Tag Archives: SPI

Re-reading the SX1231 datasheet

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While trying to debug a deadlock in my RFM69 library I noticed in the logging that I was getting a receive interrupt while putting bytes in the FIFO for transmission. 

Register 0x49 - Value 0X00 - Bits 00000000
Register 0x4a - Value 0X00 - Bits 00000000
Register 0x4b - Value 0X00 - Bits 00000000
Register 0x4c - Value 0X00 - Bits 00000000
Register 0x4d - Value 0X00 - Bits 00000000
...
22:58:47.192 Received To 0X22 a 33 byte message hello world RFM69-915-02 10-58-47 CRC Ok True
The thread 0x6a8 has exited with code 0 (0x0).
22:58:48.334 Send-hello world RFM69-915-01 10-58-48
22:58:48.351 Send-Done
22:58:48.388 Received To 0X22 a 33 byte message hello world RFM69-915-02 10-58-52 CRC Ok True
22:58:48.462 Transmit-Done
The thread 0xde4 has exited with code 0 (0x0).
22:58:53.427 Send-hello world RFM69-915-01 10-58-53
22:58:53.445 Send-Done
22:58:53.556 Transmit-Done
22:58:57.382 Received To 0X22 a 33 byte message hello world RFM69-915-02 10-58-57 CRC Ok True
The thread 0x17c has exited with code 0 (0x0).

After re-reading the RFM69CW/RFM69HCW module datasheet (based on the Semtech SX1231/SX1231H) I realised my code for loading the FIFO could be more efficient.

SX1231 Register map FIFO

Based on the timing diagram I could remove the loop which loads bytes in the FIFO for transmission.

The changes in my RFM69 library weren’t huge but I think they are also applicable to the RFM9X LoRa library as well

public void SendMessage(byte address, byte[] messageBytes)
{
#region Guard conditions
#endregion

	lock (Rfm9XRegFifoLock)
	{
		SetMode(RegOpModeMode.StandBy);

		if (PacketFormat == RegPacketConfig1PacketFormat.VariableLength)
		{
			RegisterManager.WriteByte((byte)Registers.RegFifo, (byte)(messageBytes.Length + 1)); // Additional byte for address 
		}

		RegisterManager.WriteByte((byte)Registers.RegFifo, address);

		foreach (byte b in messageBytes)
		{
				this.RegisterManager.WriteByte((byte)Registers.RegFifo, b);
		}

		SetMode(RegOpModeMode.Transmit);
	}
}

After modifications

public void SendMessage(byte address, byte[] messageBytes)
{
#region Guard conditions
...
#endregion

	SetDioPinMapping(dio0Mapping: Dio0Mapping.TransmitPacketSent);

	lock (Rfm9XRegFifoLock)
	{
		SetMode(RegOpModeMode.StandBy);

		if (PacketFormat == RegPacketConfig1PacketFormat.VariableLength)
		{
			RegisterManager.WriteByte((byte)Registers.RegFifo, (byte)(messageBytes.Length + 1)); // Additional byte for address 
		}

		RegisterManager.WriteByte((byte)Registers.RegFifo, address);

		this.RegisterManager.Write((byte)Registers.RegFifo, messageBytes);
	}
	SetMode(RegOpModeMode.Transmit);
}

After stress testing with several client devices this appears to have reduced the scope of a receive interrupt to occur while a packet was being loaded into the FIFO for transmission. I now need to dig deeper into the timing around entering different operational modes and selectively enabling event interrupts.

RFM69 hat library lockups and corruptions

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While doing yet more stress testing I noticed a couple of odd message go past and a long pause every so often when sending a message in the Visual Studio output window.

I have two Arduino devices sending addressed messages every (both individual and broadcast) to the Adafruit RFM69 HCW Radio Bonnet, on my two Windows 10 IoT Core devices every 100mSec. At the same time the windows 10 devices are sending each other a message every 5 seconds.

To help spot the pauses I added some code to mark any events where there was a significant gap. In this case ” is ASCII character for 0x22 the device address

21:10:30.746 Received To 34 a 23 byte message Hello World ---0x22:236 CRC Ok True
21:10:30.918 Received To 153 a 23 byte message Hello World ---0x99:236 CRC Ok True
21:10:31.399 Received To 34 a 23 byte message Hello World ---0x22:237 CRC Ok True
21:10:31.568 Send-hello world RFM69-915-01 09-10-31
21:10:31.580 Send-Done
21:10:31.592 Received To 34 a 33 byte message """"""""""""""""""""""""""""""""" CRC Ok True
RC-------------------------------------------
21:10:32.052 Received To 34 a 23 byte message Hello World ---0x22:238 CRC Ok True
21:10:32.225 Received To 153 a 23 byte message Hello World ---0x99:238 CRC Ok True
21:10:32.705 Received To 34 a 23 byte message Hello World ---0x22:239 CRC Ok True

There were also still some corrupted messages

21:10:30.746 Received To 34 a 23 byte message Hello World ---0x22:236 CRC Ok True
21:10:30.918 Received To 153 a 23 byte message Hello World ---0x99:236 CRC Ok True
21:10:31.399 Received To 34 a 23 byte message Hello World ---0x22:237 CRC Ok True
21:10:31.568 Send-hello world RFM69-915-01 09-10-31
21:10:31.580 Send-Done
21:10:31.592 Received To 34 a 33 byte message """"""""""""""""""""""""""""""""" CRC Ok True
RC-------------------------------------------
21:10:32.052 Received To 34 a 23 byte message Hello World ---0x22:238 CRC Ok True
21:10:32.225 Received To 153 a 23 byte message Hello World ---0x99:238 CRC Ok True
21:10:32.705 Received To 34 a 23 byte message Hello World ---0x22:239 CRC Ok True

It looks like if the base station receives a message as it is about to send a message the Rfm69Device_OnTransmit never gets called.

It also looks like every so often the transmitter gets stuck on one of Windows 10 devices effectively jamming the frequency.

Transmit stuck on
16:12:10.193 Received To 34 a 22 byte message Hello World ---0x22:65 CRC Ok True
16:12:10.360 Received To 153 a 22 byte message Hello World ---0x99:65 CRC Ok True
16:12:10.831 Received To 34 a 22 byte message Hello World ---0x22:66 CRC Ok True
16:12:10.998 Received To 153 a 22 byte message Hello World ---0x99:66 CRC Ok True
The thread 0x570 has exited with code 0 (0x0).
16:12:11.484 Send-hello world RFM69-915-01 04-12-11
16:12:11.494 Received To 34 a 22 byte message Hello World ---0x22:67 CRC Ok True
16:12:11.504 Send-Done
The thread 0x3a8 has exited with code 0 (0x0).
16:12:16.554 Send-hello world RFM69-915-01 04-12-16
16:12:16.566 Send-Done
16:12:16.660 Transmit-Done
T--------------------------------------------
16:12:16.736 Received To 153 a 22 byte message Hello World ---0x99:75 CRC Ok True
16:12:17.206 Received To 34 a 22 byte message Hello World ---0x22:76 CRC Ok True
16:12:17.374 Received To 153 a 22 byte message Hello World ---0x99:76 CRC Ok True
16:12:18.011 Received To 153 a 22 byte message Hello World ---0x99:77 CRC Ok True


Transmit stuck 
16:12:07.591 Transmit-Done
16:12:07.880 Received To 153 a 23 byte message Hello World ---0x99:137 CRC Ok True
16:12:08.533 Received To 153 a 23 byte message Hello World ---0x99:138 CRC Ok True
16:12:08.839 Received To 17 a 24 byte message Hello World ----0x11:139 CRC Ok True
16:12:09.186 Received To 153 a 23 byte message Hello World ---0x99:139 CRC Ok True
16:12:09.493 Received To 17 a 24 byte message Hello World ----0x11:140 CRC Ok True
16:12:10.799 Received To 17 a 24 byte message Hello World ----0x11:142 CRC Ok True
The thread 0xc8 has exited with code 0 (0x0).
16:12:12.567 Send-hello world RFM69-915-02 04-12-12
16:12:12.589 Send-Done
16:12:12.681 Transmit-Done
16:12:16.510 Received To 17 a 33 byte message hello world RFM69-915-01 04-12-16 CRC Ok True
16:12:16.576 Received To 153 a 22 byte message Hello World ---0x99:75 CRC Ok True
16:12:17.025 Received To 153 a 23 byte message Hello World ---0x99:151 CRC Ok True
16:12:17.214 Received To 153 a 22 byte message Hello World ---0x99:76 CRC Ok True
16:12:17.331 Received To 17 a 24 byte message Hello World ----0x11:152 CRC Ok True
The thread 0xfa0 has exited with code 0 (0x0).
16:12:17.661 Send-hello world RFM69-915-02 04-12-17
16:12:17.680 Send-Done
16:12:17.772 Transmit-Done
16:12:17.851 Received To 153 a 22 byte message Hello World ---0x99:77 CRC Ok True
16:12:18.331 Received To 153 a 23 byte message Hello World ---0x99:153 CRC Ok True
16:12:18.489 Received To 153 a 22 byte message Hello World ---0x99:78 CRC Ok True
16:12:18.638 Received To 17 a 24 byte message Hello World ----0x11:154 CRC Ok True
16:12:18.985 Received To 153 a 23 byte message Hello World ---0x99:154 CRC Ok True
16:12:19.291 Received To 17 a 24 byte message Hello World ----0x11:155 CRC Ok True
16:12:19.638 Received To 153 a 23 byte message Hello World ---0x99:155 CRC Ok True
16:12:19.944 Received To 17 a 24 byte message Hello World ----0x11:156 CRC Ok True
16:12:20.291 Received To 153 a 23 byte message Hello World ---0x99:156 CRC Ok True
16:12:20.597 Received To 17 a 24 byte message Hello World ----0x11:157 CRC Ok True

Then as rfm69Device.SetMode(Rfm69HcwDevice.RegOpModeMode.Receive) hasn’t been called no messages are received until another message is sent.

It looks like a timing issue around access to the message fifo (I have that in a critical section) so I need todo some more debugging. Maybe purging the receive buffer 

byte regPacketConfig2 = RegisterManager.ReadByte((byte)Rfm69HcwDevice.Registers.RegPacketConfig2);
			regPacketConfig2 |= 0b00000100;
			RegisterManager.WriteByte((byte)Rfm69HcwDevice.Registers.RegPacketConfig2, regPacketConfig2);

The adfruit.io RFM69 shield has DIO2 which can be used for automode operation which might remove some of the synchronisation issues I am encountering.

RFM69 hat library h WWWWWWWWoo

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Again, while doing some stress testing I noticed an odd message go past in the Visual Studio output window. I had multiple devices sending addressed messages (both individual and broadcast) to the Adafruit RFM69 HCW Radio Bonnet, on my Windows 10 IoT Core device while it was sending a message every 5 seconds.

Received From 102 a 15 byte message Hello World:161
23:42:33.343 RegIrqFlags2 01100110
23:42:33.356 RegIrqFlags1 11011001
23:42:33.374 Address 0X99 10011001
Received From 153 a 15 byte message Hello World:106
23:42:33.761 RegIrqFlags2 01100110
23:42:33.774 RegIrqFlags1 11011001
23:42:33.791 Address 0X66 01100110
Received From 102 a 15 byte message Hello World:162
The thread 0xd20 has exited with code 0 (0x0).
23:42:34.500 RegIrqFlags2 01100110
23:42:34.501 Send-hello world 11:42:34 PM
23:42:34.520 RegIrqFlags1 11011001
23:42:34.545 Send-Done
23:42:34.551 Address 0X10 00010000
Received From 16 a 15 byte message h    WWWWWWWWoo
23:42:34.686 RegIrqFlags2 00001000
23:42:34.701 RegIrqFlags1 10110000
23:42:34.715 Transmit-Done
Transmit-Done
23:42:34.902 RegIrqFlags2 01100110
23:42:34.915 RegIrqFlags1 11011001
23:42:34.931 Address 0X66 01100110
Received From 102 a 15 byte message Hello World:163
23:42:35.626 RegIrqFlags2 01100110
23:42:35.640 RegIrqFlags1 11011001
23:42:35.659 Address 0X99 10011001
Received From 153 a 15 byte message Hello World:108
23:42:36.042 RegIrqFlags2 01100110
23:42:36.055 RegIrqFlags1 11011001
23:42:36.073 Address 0X66 01100110

The RegIrqFlags2 CrcOk (bit 1) was set and the message was corrupt.

RegIrqFlags2 bit flags from SX1231 datasheet

I have added code to check the CRC on inbound messages if this functionality is enabled. So the library can be used with CRCs disabled I have added a flag to the OnDataReceivedEventArgs class to indicate whether the CRC on the inbound message was OK.

private readonly Object Rfm9XRegFifoLock = new object();
...
private void ProcessPayloadReady(RegIrqFlags1 irqFlags1, RegIrqFlags2 irqFlags2)
{
	byte? address = null;
	byte numberOfBytes;
	byte[] messageBytes;

	lock (Rfm9XRegFifoLock)
	{
		// Read the length of the buffer if variable length packets
		if (PacketFormat == RegPacketConfig1PacketFormat.VariableLength)
		{
			numberOfBytes = RegisterManager.ReadByte((byte)Rfm69HcwDevice.Registers.RegFifo);
		}
		else
		{
			numberOfBytes = PayloadLength;
		}

		// Remove the address from start of the payload
		if (AddressingEnabled)
		{
			address = RegisterManager.ReadByte((byte)Rfm69HcwDevice.Registers.RegFifo);

			Debug.WriteLine("{0:HH:mm:ss.fff} Address 0X{1:X2} {2}", DateTime.Now, address, Convert.ToString((byte)address, 2).PadLeft(8, '0'));
			numberOfBytes--;
		}

		// Allocate a buffer for the payload and read characters from the Fifo
		messageBytes = new byte[numberOfBytes];

		for (int i = 0; i < numberOfBytes; i++)
		{
			messageBytes[i] = RegisterManager.ReadByte((byte)Rfm69HcwDevice.Registers.RegFifo);
		}
	}
...
public void SendMessage(byte[] messageBytes)
{
#region Guard conditions
#endregion

	lock (Rfm9XRegFifoLock)
	{
		SetMode(RegOpModeMode.StandBy);

		if (PacketFormat == RegPacketConfig1PacketFormat.VariableLength)
		{
			RegisterManager.WriteByte((byte)Registers.RegFifo, (byte)messageBytes.Length);
		}

		foreach (byte b in messageBytes)
		{
			this.RegisterManager.WriteByte((byte)Registers.RegFifo, b);
		}

		SetMode(RegOpModeMode.Transmit);
	}
}

I can most probably reduce the duration which I hold the lock for but that will require some more stress testing.

RFM69 hat library Hello Woooooooo

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While doing some stress testing I noticed an odd message go past in the Visual Studio output window. I had multiple devices sending addressed messages (both individual and broadcast) to the Adafruit RFM69 HCW Radio Bonnet, on my Windows 10 IoT Core device while it was sending a message every 5 seconds.

Received From 153 a 13 byte message Hello World:7
18:43:56.544 RegIrqFlags2 01100110
18:43:56.558 RegIrqFlags1 11011001
18:43:56.575 Address 0X66 01100110
Received From 102 a 15 byte message Hello World:162
The thread 0x254 has exited with code 0 (0x0).
18:43:57.699 Send-hello world 6:43:57 PM
18:43:57.699 RegIrqFlags2 01100110
18:43:57.731 RegIrqFlags1 10000000
18:43:57.747 Address 0X66 01100110
18:43:57.765 Send-Done
Received From 102 a 15 byte message Hello Woooooooo
18:43:57.987 RegIrqFlags2 00001000
18:43:58.003 RegIrqFlags1 10110000
18:43:58.017 Transmit-Done
Transmit-Done
18:43:58.825 RegIrqFlags2 01100110
18:43:58.838 RegIrqFlags1 11011001
18:43:58.857 Address 0X66 01100110
Received From 102 a 15 byte message Hello World:164
18:43:59.966 RegIrqFlags2 01100110
18:43:59.979 RegIrqFlags1 11011001
18:43:59.998 Address 0X66 01100110

The odd thing was that the RegIrqFlags2 CrcOk (bit 1) was set but the message was still corrupt.

RegIrqFlags2 bit flags from SX1231 datasheet

After looking at the code I think the problem was the reading of the received message bytes from the device FIFO and the writing of bytes of message to be transmitted into the device FIFO overlapped. To stop this occurring again I have added code to synchronise access (using a Lock) to the FIFO. 

private readonly Object Rfm9XRegFifoLock = new object();
...
private void ProcessPayloadReady(RegIrqFlags1 irqFlags1, RegIrqFlags2 irqFlags2)
{
	byte? address = null;
	byte numberOfBytes;
	byte[] messageBytes;

	lock (Rfm9XRegFifoLock)
	{
		// Read the length of the buffer if variable length packets
		if (PacketFormat == RegPacketConfig1PacketFormat.VariableLength)
		{
			numberOfBytes = RegisterManager.ReadByte((byte)Rfm69HcwDevice.Registers.RegFifo);
		}
		else
		{
			numberOfBytes = PayloadLength;
		}

		// Remove the address from start of the payload
		if (AddressingEnabled)
		{
			address = RegisterManager.ReadByte((byte)Rfm69HcwDevice.Registers.RegFifo);

			Debug.WriteLine("{0:HH:mm:ss.fff} Address 0X{1:X2} {2}", DateTime.Now, address, Convert.ToString((byte)address, 2).PadLeft(8, '0'));
			numberOfBytes--;
		}

		// Allocate a buffer for the payload and read characters from the Fifo
		messageBytes = new byte[numberOfBytes];

		for (int i = 0; i < numberOfBytes; i++)
		{
			messageBytes[i] = RegisterManager.ReadByte((byte)Rfm69HcwDevice.Registers.RegFifo);
		}
	}
...
public void SendMessage(byte[] messageBytes)
{
#region Guard conditions
#endregion

	lock (Rfm9XRegFifoLock)
	{
		SetMode(RegOpModeMode.StandBy);

		if (PacketFormat == RegPacketConfig1PacketFormat.VariableLength)
		{
			RegisterManager.WriteByte((byte)Registers.RegFifo, (byte)messageBytes.Length);
		}

		foreach (byte b in messageBytes)
		{
			this.RegisterManager.WriteByte((byte)Registers.RegFifo, b);
		}

		SetMode(RegOpModeMode.Transmit);
	}
}

The code has been running for a day without any corrupted messages so the lock appears to be working. I can most probably reduce the duration which I hold the lock for but that will require some more stress testing.

RFM69 hat library Part12E

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Enums and Masks – RegDIOMapping1 & RegDIOMapping2

The RFM69CW/RFM69HCW module (based on the Semtech SX1231/SX1231H) has configurable digital outputs (RegDIOMapping1 & RegDIOMapping2) . Which I use to trigger interrupts on my Windows 10 IoT Core or Arduino devices. Currently (Sep 2019) the library only supports the mapping of the digital outputs D0 & D1 when the RFM69 is in Packet Mode.

RegiDIOMapping0 & RegDIOMapping2 settings for DIO thru DIO5

I added some additional constants and enumerations for the other settings configured in RegDioMapping1 & RegDioMapping2.

// RegDioMapping1 & RegDioMapping2 Packet Mode Table 22 pg48
// DIO 0 Bits 7&6 of RegDioMapping1
[Flags]
public enum Dio0Mapping
{
	// Sleep
	// Standby
	// Frequency Synthesis
	// Reserved 00-10
	FrequencySynthesisPllLock = 0b11000000,
	ReceiveCrcOk = 0b00000000,
	ReceivePayloadReady = 0b01000000,
	ReceiveSyncAddress = 0b10000000,
	ReceiveRssi = 0b11000000,
	TransmitPacketSent = 0b00000000,
	TransmitTxReady = 0b01000000,
	// Reserved 10
	PllLock = 0b11000000
}
const Dio0Mapping Dio0MappingDefault = 0x00;

// DIO 1 Bits 5&4 of RegDioMapping1
public enum Dio1Mapping
{
	SleepFifoLevel = 0b00000000,
	SleepFifoFull = 0b00010000,
	SleepFifoNotEmpty = 0b00100000,
	// Reserved 11
	StandByFifoLevel = 0b00000000,
	StandByFifoFull = 0b00010000,
	StandByFifoNotEmpty = 0b00100000,
	FrequencySynthesisFifoLevel = 0b00000000,
	FrequencySynthesisFifoFull = 0b00010000,
	FrequencySynthesisFifoNotEmpty = 0b00100000,
	FrequencySynthesisPllLock = 0b00110000,
	ReceiveFifoLevel = 0b00000000,
	ReceiveFifoFull = 0b00010000,
	ReceiveFifoNotEmpty = 0b00100000,
	ReceiveTimeout = 0b00110000,
	TransmitFifoLevel = 0b00000000,
	TransmitFifoFull = 0b00010000,
	TransmitFifoNotEmpty = 0b00100000,
	TransmitPllLock = 0b00110000,
}
const Dio1Mapping Dio1MappingDefault = 0x00;

// DIO 2 Bits 3&2 of RegDioMapping1
public enum Dio2Mapping
{
}
const Dio2Mapping Dio2MappingDefault = 0x00;

// DIO 2 Bits 1&0 of RegDioMapping1
public enum Dio3Mapping
{
}
const Dio3Mapping Dio3MappingDefault = 0x00;

// DIO 2 Bits 7&6 of RegDioMapping2
public enum Dio4Mapping
{
}
const Dio4Mapping Dio4MappingDefault = 0x00;

// DIO 2 Bits 5&4 of RegDioMapping2
public enum Dio5Mapping
{
}
const Dio5Mapping Dio5MappingDefault = 0x00;

// RegDioMapping2 Bits 2-0
public enum ClockOutDioMapping : byte
{
	FXOsc = 0b00000000,
	FXOscDiv2 = 0b00000001,
	FXOscDiv4 = 0b00000010,
	FXOscDiv8 = 0b00000011,
	FXOscDiv16 = 0b00000100,
	FXOscDiv32 = 0b00000101,
	RC = 0b00000110,
	Off = 0b00000111,
}
public const ClockOutDioMapping ClockOutDioMappingDefault = ClockOutDioMapping.Off;

I also added some code to the initialise method to set the RegDioMapping1 & RegDioMapping1 only if the values were not the defaults.

public void Initialise(RegOpModeMode modeAfterInitialise,
	bool sequencer = RegOpModeSequencerDefault,
	bool listen = RegOpModeListenDefault,
	BitRate bitRate = BitRateDefault,
	ushort frequencyDeviation = frequencyDeviationDefault,
	double frequency = FrequencyDefault,
	AfcLowBeta afcLowBeta = AfcLowBetaDefault,
	ListenModeIdleResolution listenModeIdleResolution = ListenModeIdleResolutionDefault, ListenModeRXTime listenModeRXTime = ListenModeRXTimeDefault, ListenModeCriteria listenModeCrieria = ListenModeCriteriaDefault, ListenModeEnd listenModeEnd = ListenModeEndDefault,
	byte listenCoefficientIdle = ListenCoefficientIdleDefault,
	byte listenCoefficientReceive = ListenCoefficientReceiveDefault,
	bool pa0On = pa0OnDefault, bool pa1On = pa1OnDefaut, bool pa2On = pa2OnDefault, byte outputpower = OutputpowerDefault,
	PaRamp paRamp = PaRampDefault,
	bool ocpOn = OcpOnDefault, byte ocpTrim = OcpTrimDefault,
	LnaZin lnaZin = LnaZinDefault, LnaCurrentGain lnaCurrentGain = LnaCurrentGainDefault, LnaGainSelect lnaGainSelect = LnaGainSelectDefault,
	byte dccFrequency = DccFrequencyDefault, RxBwMant rxBwMant = RxBwMantDefault, byte RxBwExp = RxBwExpDefault,
	byte dccFreqAfc = DccFreqAfcDefault, byte rxBwMantAfc = RxBwMantAfcDefault, byte bxBwExpAfc = RxBwExpAfcDefault,
	Dio0Mapping dio0Mapping = Dio0MappingDefault,
	Dio1Mapping dio1Mapping = Dio1MappingDefault,
	Dio2Mapping dio2Mapping = Dio2MappingDefault,
	Dio3Mapping dio3Mapping = Dio3MappingDefault,
	Dio4Mapping dio4Mapping = Dio4MappingDefault,
	Dio5Mapping dio5Mapping = Dio5MappingDefault,
	ClockOutDioMapping clockOutDioMapping = ClockOutDioMappingDefault,
	ushort preambleSize = PreambleSizeDefault,
	RegSyncConfigFifoFileCondition? syncFifoFileCondition = null, byte? syncTolerance = null, byte[] syncValues = null,
	RegPacketConfig1PacketFormat packetFormat = RegPacketConfig1PacketFormat.FixedLength,
	RegPacketConfig1DcFree packetDcFree = RegPacketConfig1DcFreeDefault,
	bool packetCrc = PacketCrcOnDefault,
	bool packetCrcAutoClear = PacketCrcAutoClearDefault,
	byte payloadLength = PayloadLengthDefault,
	byte? addressNode = null, byte? addressbroadcast = null,
	TxStartCondition txStartCondition = TxStartConditionDefault, byte fifoThreshold = FifoThresholdDefault,
	byte interPacketRxDelay = InterPacketRxDelayDefault, bool autoRestartRx = AutoRestartRxDefault,
	byte[] aesKey = null
	)
...
	// RegDioMapping1
	if ((dio0Mapping != Dio0MappingDefault) ||
	    (dio1Mapping != Dio1MappingDefault) ||
	    (dio2Mapping != Dio2MappingDefault) ||
	    (dio3Mapping != Dio3MappingDefault))
	{
		byte regDioMapping1Value = (byte)dio0Mapping;

		regDioMapping1Value |= (byte)dio1Mapping;
		regDioMapping1Value |= (byte)dio2Mapping;
		regDioMapping1Value |= (byte)dio3Mapping;

		RegisterManager.WriteByte((byte)Registers.RegDioMapping1, regDioMapping1Value);
	}

	// RegDioMapping2
	if ((dio4Mapping != Dio4MappingDefault) ||
		 (dio5Mapping != Dio5MappingDefault) ||
		 (clockOutDioMapping != ClockOutDioMappingDefault ))
	{
		byte regDioMapping2Value = (byte)dio4Mapping;

		regDioMapping2Value |= (byte)dio5Mapping;
		regDioMapping2Value |= (byte)clockOutDioMapping;

		RegisterManager.WriteByte((byte)Registers.RegDioMapping2, regDioMapping2Value);
	}

I had several failed attempts at defining suitable enumerations for configuring the RegDioMapping1 & RegDioMapping2 registers. I initially started with an enumeration for each Mode (Sleep, StandBy etc.) but the implementation was quite complex. The initial version only supports DIO0 & DIO1 as most of the shields I have, only DIO0 adn/or DIO1 are connected.

RFM69 hat library Part12D

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Enums and Masks – Packet lengths, addressing & CRCs

The RFM69CW/RFM69HCW module (based on the Semtech SX1231/SX1231H) has configurable (RegSyncConfig) synchronisation sequences (the length, tolerance for errors and the individual byte values).

By default synchronisation is enabled and a default sequence of bytes is used, in my library synchronisation is NOT enabled until a SyncValue is provided.

I added some additional constants and enumerations for the other settings configured in RegSyncConfig.

// RegSyncConfig 
// This is private because default ignored and flag set based on SyncValues parameter being specified rather than default
private enum RegSyncConfigSyncOn
{
	Off = 0b00000000,
	On = 0b10000000
}

public enum RegSyncConfigFifoFileCondition
{
	SyncAddressInterrupt = 0b00000000,
	FifoFillCondition =    0b01000000
}

private const RegSyncConfigFifoFileCondition SyncFifoFileConditionDefault = RegSyncConfigFifoFileCondition.SyncAddressInterrupt;
readonly byte[] SyncValuesDefault = {0x01, 0x01, 0x01, 0x01};
public const byte SyncValuesSizeDefault = 4;
public const byte SyncValuesSizeMinimum = 1;
public const byte SyncValuesSizeMaximum = 8;

private const byte SyncToleranceDefault = 0;
public const byte SyncToleranceMinimum = 0;
public const byte SyncToleranceMaximum = 7;

I also added some guard conditions to the initialise method which validate the syncFifoFileCondition, syncTolerance and syncValues length.

public void Initialise(RegOpModeMode modeAfterInitialise,
	BitRate bitRate = BitRateDefault,
	ushort frequencyDeviation = frequencyDeviationDefault,
	double frequency = FrequencyDefault,
	ListenModeIdleResolution listenModeIdleResolution = ListenModeIdleResolutionDefault, ListenModeRXTime listenModeRXTime = ListenModeRXTimeDefault, ListenModeCrieria listenModeCrieria = ListenModeCrieriaDefault, ListenModeEnd listenModeEnd = ListenModeEndDefault,
	byte listenCoefficientIdle = ListenCoefficientIdleDefault,
	byte listenCoefficientReceive = ListenCoefficientReceiveDefault,
	bool pa0On = pa0OnDefault, bool pa1On = pa1OnDefaut, bool pa2On = pa2OnDefault, byte outputpower = OutputpowerDefault,
	PaRamp paRamp = PaRampDefault,
	bool ocpOn = OcpOnDefault, byte ocpTrim = OcpTrimDefault,
	LnaZin lnaZin = LnaZinDefault, LnaCurrentGain lnaCurrentGain = LnaCurrentGainDefault, LnaGainSelect lnaGainSelect = LnaGainSelectDefault,
	byte dccFrequency = DccFrequencyDefault, RxBwMant rxBwMant = RxBwMantDefault, byte RxBwExp = RxBwExpDefault,
	byte dccFreqAfc = DccFreqAfcDefault, byte rxBwMantAfc = RxBwMantAfcDefault, byte bxBwExpAfc = RxBwExpAfcDefault,
	ushort preambleSize = PreambleSizeDefault,
	RegSyncConfigFifoFileCondition? syncFifoFileCondition = null, byte? syncTolerance = null, byte[] syncValues = null,
	RegPacketConfig1PacketFormat packetFormat = RegPacketConfig1PacketFormat.FixedLength,
	RegPacketConfig1DcFree packetDcFree = RegPacketConfig1DcFreeDefault,
	bool packetCrc = PacketCrcOnDefault,
	bool packetCrcAutoClearOff = PacketCrcAutoClearOffDefault,
	RegPacketConfig1CrcAddressFiltering packetAddressFiltering = PacketAddressFilteringDefault,
	byte payloadLength = PayloadLengthDefault,
	byte addressNode = NodeAddressDefault, byte addressbroadcast = BroadcastAddressDefault,
	TxStartCondition txStartCondition = TxStartConditionDefault, byte fifoThreshold = FifoThresholdDefault,
	byte interPacketRxDelay = InterPacketRxDelayDefault, bool restartRx = RestartRxDefault, bool autoRestartRx = AutoRestartRxDefault,
	byte[] aesKey = null
	)
{
	RegOpModeModeCurrent = modeAfterInitialise;
	PacketFormat = packetFormat;

	#region RegSyncConfig + RegSyncValue1 to RegSyncValue8 guard conditions
	if (syncValues != null)
	{
		// If sync enabled (i.e. SyncValues array provided) check that SyncValues not to short/long and SyncTolerance not to small/big
		if ((syncValues.Length < SyncValuesSizeMinimum) || (syncValues.Length > SyncValuesSizeMaximum))
		{
			throw new ArgumentException($"The syncValues array length must be between {SyncValuesSizeMinimum} and {SyncValuesSizeMaximum} bytes", "syncValues");
		}
		if (syncTolerance.HasValue)
		{
			if ((syncTolerance < SyncToleranceMinimum) || (syncTolerance > SyncToleranceMaximum))
			{
				throw new ArgumentException($"The syncTolerance size must be between {SyncToleranceMinimum} and {SyncToleranceMaximum}", "syncTolerance");
			}
		}
	}
	else
	{
		// If sync not enabled (i.e. SyncValues array null) check that no syncFifoFileCondition or syncTolerance configuration specified
		if (syncFifoFileCondition.HasValue)
		{
			throw new ArgumentException($"If Sync not enabled syncFifoFileCondition is not supported", "syncFifoFileCondition");
		}

		if (syncTolerance.HasValue)
		{
			throw new ArgumentException($"If Sync not enabled SyncTolerance is not supported", "syncTolerance");
		}
	}
	#endregion

I also ensure that the syncFifoFileCondition and syncTolerance are not specified if synchronisation is not enabled.

The library also supports the built in RFRM69 node and broadcast addressing which is enabled when the AddressNode and/or AddressBroadcast parameters of the Initialise method are set.

RegPacketConfig1 address filtering options

My first attempt at getting encryption and addressing working together failed badly, the Windows 10 IoT Core device didn’t receive any addressed messages when encryption was enabled. So, I went back and re-read the datasheet again and noticed

“If the address filtering is expected then AddressFiltering must be enabled on the transmitter side as well to prevent address byte to be encrypted”(Sic).

The Arduino client code had to be modified so I could set the node + broadcast address registers and AddressFiltering bit flag in RegPacketConfig1

My RMRFM69.h modifications

enum moduleType {RFM65, RFM65C, RFM69, RFM69C, RFM69H, RFM69HC};
	
 #define ADDRESS_NODE_DEFAULT 0x0
 #define ADDRESS_BROADCAST_DEFAULT 0x0
 #define ADDRESSING_ENABLED_NODE 0x2
 #define ADDRESSING_ENABLED_NODE_AND_BROADCAST 0x4

	class RMRFM69
	{
	 public:
		 RMRFM69(SPIClass &spiPort, byte csPin, byte dio0Pin, byte rstPin);
		 modulationType Modulation; //OOK/FSK/GFSK
		 moduleType COB;				//Chip on board
		 uint32_t Frequency;			//unit: KHz
		 uint32_t SymbolTime;			//unit: ns
		 uint32_t Devation;				//unit: KHz
		 word BandWidth;				//unit: KHz
		 byte OutputPower;				//unit: dBm   range: 0-31 [-18dBm~+13dBm] for RFM69/RFM69C
										//            range: 0-31 [-11dBm~+20dBm] for RFM69H/RFM69HC
		 word PreambleLength;			//unit: byte

		 bool CrcDisable; //fasle: CRC enable�� & use CCITT 16bit
						  //true : CRC disable
		 bool CrcMode;	//false: CCITT

		 bool FixedPktLength; //false: for contain packet length in Tx message, the same mean with variable lenth
							  //true : for doesn't include packet length in Tx message, the same mean with fixed length
		 bool AesOn;		  //false:
							  //true:
		 bool AfcOn;		  //false:
							  //true:
		 byte SyncLength;	 //unit: none, range: 1-8[Byte], value '0' is not allowed!
		 byte SyncWord[8];
		 byte PayloadLength; //PayloadLength is need to be set a value, when FixedPktLength is true.
		 byte AesKey[16];	//AES Key block, note [0]->[15] == MSB->LSB
		 byte AddressNode = ADDRESS_NODE_DEFAULT;
		 byte AddressBroadcast = ADDRESS_BROADCAST_DEFAULT;

		 void vInitialize(void);
		 void vConfig(void);
		 void vGoRx(void);
		 void vGoStandby(void);
		 void vGoSleep(void);
		 bool bSendMessage(byte msg[], byte length);
		 bool bSendMessage(byte Address, byte msg[], byte length);
		 byte bGetMessage(byte msg[]);
		 void vRF69SetAesKey(void);
		 void vTrigAfc(void);

		 void vDirectRx(void);			  //go continuous rx mode, with init. inside
		 void vChangeFreq(uint32_t freq); //change frequency
		 byte bReadRssi(void);			  //read rssi value
		 void dumpRegisters(Stream& out);

My RMRFM69.cpp modifications in vConfig

 if(!CrcDisable)
 	{
 	i += CrcOn;
	if(CrcMode)
		i += CrcCalc_IBM;
	else
		i += CrcCalc_CCITT;
	}

if((AddressNode!=ADDRESS_NODE_DEFAULT) || (AddressBroadcast==ADDRESS_BROADCAST_DEFAULT))
   {
      i += ADDRESSING_ENABLED_NODE;
   }

if((AddressNode!=ADDRESS_NODE_DEFAULT) || (AddressBroadcast!=ADDRESS_BROADCAST_DEFAULT))
  {
     i += ADDRESSING_ENABLED_NODE_AND_BROADCAST;
  }

 vSpiWrite(((word)RegPacketConfig1<<8)+i);

I also validate the lengths of the messages to be sent taking into account whether encryption is enabled\disabled.

RFM69 hat library Part12C

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Enums and Masks – Synchronisation

The RFM69CW/RFM69HCW module (based on the Semtech SX1231/SX1231H) has configurable (RegSyncConfig) synchronisation sequences (the length, tolerance for errors and the individual byte values).

By default synchronisation is enabled and a default sequence of bytes is used, in my library synchronisation is NOT enabled until a SyncValue is provided.

I added some additional constants and enumerations for the other settings configured in RegSyncConfig.

// RegSyncConfig 
// This is private because default ignored and flag set based on SyncValues parameter being specified rather than default
private enum RegSyncConfigSyncOn
{
	Off = 0b00000000,
	On = 0b10000000
}

public enum RegSyncConfigFifoFileCondition
{
	SyncAddressInterrupt = 0b00000000,
	FifoFillCondition =    0b01000000
}

private const RegSyncConfigFifoFileCondition SyncFifoFileConditionDefault = RegSyncConfigFifoFileCondition.SyncAddressInterrupt;
readonly byte[] SyncValuesDefault = {0x01, 0x01, 0x01, 0x01};
public const byte SyncValuesSizeDefault = 4;
public const byte SyncValuesSizeMinimum = 1;
public const byte SyncValuesSizeMaximum = 8;

private const byte SyncToleranceDefault = 0;
public const byte SyncToleranceMinimum = 0;
public const byte SyncToleranceMaximum = 7;

I also added some guard conditions to the initialise method which validate the syncFifoFileCondition, syncTolerance and syncValues length.

public void Initialise(RegOpModeMode modeAfterInitialise,
	BitRate bitRate = BitRateDefault,
	ushort frequencyDeviation = frequencyDeviationDefault,
	double frequency = FrequencyDefault,
	ListenModeIdleResolution listenModeIdleResolution = ListenModeIdleResolutionDefault, ListenModeRXTime listenModeRXTime = ListenModeRXTimeDefault, ListenModeCrieria listenModeCrieria = ListenModeCrieriaDefault, ListenModeEnd listenModeEnd = ListenModeEndDefault,
	byte listenCoefficientIdle = ListenCoefficientIdleDefault,
	byte listenCoefficientReceive = ListenCoefficientReceiveDefault,
	bool pa0On = pa0OnDefault, bool pa1On = pa1OnDefaut, bool pa2On = pa2OnDefault, byte outputpower = OutputpowerDefault,
	PaRamp paRamp = PaRampDefault,
	bool ocpOn = OcpOnDefault, byte ocpTrim = OcpTrimDefault,
	LnaZin lnaZin = LnaZinDefault, LnaCurrentGain lnaCurrentGain = LnaCurrentGainDefault, LnaGainSelect lnaGainSelect = LnaGainSelectDefault,
	byte dccFrequency = DccFrequencyDefault, RxBwMant rxBwMant = RxBwMantDefault, byte RxBwExp = RxBwExpDefault,
	byte dccFreqAfc = DccFreqAfcDefault, byte rxBwMantAfc = RxBwMantAfcDefault, byte bxBwExpAfc = RxBwExpAfcDefault,
	ushort preambleSize = PreambleSizeDefault,
	RegSyncConfigFifoFileCondition? syncFifoFileCondition = null, byte? syncTolerance = null, byte[] syncValues = null,
	RegPacketConfig1PacketFormat packetFormat = RegPacketConfig1PacketFormat.FixedLength,
	RegPacketConfig1DcFree packetDcFree = RegPacketConfig1DcFreeDefault,
	bool packetCrc = PacketCrcOnDefault,
	bool packetCrcAutoClearOff = PacketCrcAutoClearOffDefault,
	RegPacketConfig1CrcAddressFiltering packetAddressFiltering = PacketAddressFilteringDefault,
	byte payloadLength = PayloadLengthDefault,
	byte addressNode = NodeAddressDefault, byte addressbroadcast = BroadcastAddressDefault,
	TxStartCondition txStartCondition = TxStartConditionDefault, byte fifoThreshold = FifoThresholdDefault,
	byte interPacketRxDelay = InterPacketRxDelayDefault, bool restartRx = RestartRxDefault, bool autoRestartRx = AutoRestartRxDefault,
	byte[] aesKey = null
	)
{
	RegOpModeModeCurrent = modeAfterInitialise;
	PacketFormat = packetFormat;

	#region RegSyncConfig + RegSyncValue1 to RegSyncValue8 guard conditions
	if (syncValues != null)
	{
		// If sync enabled (i.e. SyncValues array provided) check that SyncValues not to short/long and SyncTolerance not to small/big
		if ((syncValues.Length < SyncValuesSizeMinimum) || (syncValues.Length > SyncValuesSizeMaximum))
		{
			throw new ArgumentException($"The syncValues array length must be between {SyncValuesSizeMinimum} and {SyncValuesSizeMaximum} bytes", "syncValues");
		}
		if (syncTolerance.HasValue)
		{
			if ((syncTolerance < SyncToleranceMinimum) || (syncTolerance > SyncToleranceMaximum))
			{
				throw new ArgumentException($"The syncTolerance size must be between {SyncToleranceMinimum} and {SyncToleranceMaximum}", "syncTolerance");
			}
		}
	}
	else
	{
		// If sync not enabled (i.e. SyncValues array null) check that no syncFifoFileCondition or syncTolerance configuration specified
		if (syncFifoFileCondition.HasValue)
		{
			throw new ArgumentException($"If Sync not enabled syncFifoFileCondition is not supported", "syncFifoFileCondition");
		}

		if (syncTolerance.HasValue)
		{
			throw new ArgumentException($"If Sync not enabled SyncTolerance is not supported", "syncTolerance");
		}
	}
	#endregion

I also ensure that the syncFifoFileCondition and syncTolerance are not specified if synchronisation is not enabled.

The Arduino client code works though I need modify it so I can do more testing of the initialise method parameter options.

RFM69 hat library Part12B

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Enums and Masks – Encryption

The RFM69CW/RFM69HCW module (based on the Semtech SX1231/SX1231H) has built in support for 128bit Advanced Encryption Standard(AES) encoding of message payloads. To make encryption easy to configure I added some additional constants and enumerations for the other settings configured in RegPacketConfig2.

// RegPacketConfig2
private const byte InterPacketRxDelayDefault = 0;
public const byte InterPacketRxDelayMinimum = 0x0;
public const byte InterPacketRxDelayMaximum = 0xF;

private const bool RestartRxDefault = false;
[Flags]
private enum RegPacketConfig2RestartRxDefault : byte
{
	Off = 0b00000000,
	On = 0b00000100,
}

private const bool AutoRestartRxDefault = true;
[Flags]
private enum RegPacketConfig2AutoRestartRxDefault : byte
{
	Off = 0b00000000,
	On = 0b00000010,
}

[Flags]
private enum RegPacketConfig2Aes : byte
{
	Off = 0b00000000,
	On = 0b00000001,
}
public const byte AesKeyLength = 16;

I then added some guard conditions to the initialise method to validate the InterPacketRxDelay and the encryption key length.

public void Initialise(RegOpModeMode modeAfterInitialise,
	BitRate bitRate = BitRateDefault,
	ushort frequencyDeviation = frequencyDeviationDefault,
	double frequency = FrequencyDefault,
	ListenModeIdleResolution listenModeIdleResolution = ListenModeIdleResolutionDefault, ListenModeRXTime listenModeRXTime = ListenModeRXTimeDefault, ListenModeCrieria listenModeCrieria = ListenModeCrieriaDefault, ListenModeEnd listenModeEnd = ListenModeEndDefault,
	byte listenCoefficientIdle = ListenCoefficientIdleDefault,
	byte listenCoefficientReceive = ListenCoefficientReceiveDefault,
	bool pa0On = pa0OnDefault, bool pa1On = pa1OnDefaut, bool pa2On = pa2OnDefault, byte outputpower = OutputpowerDefault,
	PaRamp paRamp = PaRampDefault,
	bool ocpOn = OcpOnDefault, byte ocpTrim = OcpTrimDefault,
	LnaZin lnaZin = LnaZinDefault, LnaCurrentGain lnaCurrentGain = LnaCurrentGainDefault, LnaGainSelect lnaGainSelect = LnaGainSelectDefault,
	byte dccFrequency = DccFrequencyDefault, RxBwMant rxBwMant = RxBwMantDefault, byte RxBwExp = RxBwExpDefault,
	byte dccFreqAfc = DccFreqAfcDefault, byte rxBwMantAfc = RxBwMantAfcDefault, byte bxBwExpAfc = RxBwExpAfcDefault,
	ushort preambleSize = PreambleSizeDefault,
	bool syncOn = SyncOnDefault, SyncFifoFileCondition syncFifoFileCondition = SyncFifoFileConditionDefault, byte syncSize = SyncSizeDefault, byte syncTolerance = SyncToleranceDefault, byte[] syncValues = null,
	RegPacketConfig1PacketFormat packetFormat = RegPacketConfig1PacketFormat.FixedLength,
	RegPacketConfig1DcFree packetDcFree = RegPacketConfig1DcFreeDefault,
	bool packetCrc = PacketCrcOnDefault,
	bool packetCrcAutoClearOff = PacketCrcAutoClearOffDefault,
	RegPacketConfig1CrcAddressFiltering packetAddressFiltering = PacketAddressFilteringDefault,
	byte payloadLength = PayloadLengthDefault,
	byte addressNode = NodeAddressDefault, byte addressbroadcast = BroadcastAddressDefault,
	TxStartCondition txStartCondition = TxStartConditionDefault, byte fifoThreshold = FifoThresholdDefault,
	byte interPacketRxDelay = InterPacketRxDelayDefault, bool restartRx = RestartRxDefault, bool autoRestartRx = AutoRestartRxDefault,
	byte[] aesKey = null
)
{
	RegOpModeModeCurrent = modeAfterInitialise;
	PacketFormat = packetFormat;

	#region Guard Conditions
	if ((interPacketRxDelay < InterPacketRxDelayMinimum ) || (interPacketRxDelay > InterPacketRxDelayMaximum))
	{
		throw new ArgumentException($"The interPacketRxDelay must be between {InterPacketRxDelayMinimum} and {InterPacketRxDelayMaximum}", "interPacketRxDelay");
	}
	if ((aesKey != null) && (aesKey.Length != AesKeyLength))
	{
		throw new ArgumentException($"The AES key must be {AesKeyLength} bytes", "aesKey");
	}
	#endregion

This required some modifications to the run method to catch the new exceptions gracefully.

public void Run(IBackgroundTaskInstance taskInstance)
{
	byte[] syncValues ={0xAA, 0x2D, 0xD4};
	byte[] aesKeyValues = {0x0, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0X0E, 0X0F };

	rfm69Device.RegisterDump();

	try
	{
		rfm69Device.Initialise(Rfm69HcwDevice.RegOpModeMode.StandBy,
			bitRate: Rfm69HcwDevice.BitRate.bps4K8,
			frequency: 915000000.0, frequencyDeviation: 0X023d,
			dccFrequency: 0x1,rxBwMant: Rfm69HcwDevice.RxBwMant.RxBwMant20, RxBwExp:0x2,
			preambleSize: 16,
			syncSize: 3,
			syncValues: syncValues,
			packetFormat: Rfm69HcwDevice.RegPacketConfig1PacketFormat.VariableLength,
			packetCrc:true,
			aesKey: aesKeyValues
			);

		rfm69Device.RegisterDump();

		// RegDioMapping1
		rfm69Device.RegisterManager.WriteByte(0x26, 0x01);

		rfm69Device.RegisterDump();
		while (true)
		{
			string message = "hello world " + DateTime.Now.ToLongTimeString();

			byte[] messageBuffer = UTF8Encoding.UTF8.GetBytes(message);

			Debug.WriteLine("{0:HH:mm:ss.fff} Send-{1}", DateTime.Now, message);
			rfm69Device.SendMessage(messageBuffer);

			Debug.WriteLine("{0:HH:mm:ss.fff} Send-Done", DateTime.Now);

			Task.Delay(5000).Wait();
		}
	}
	catch( Exception ex)
	{
		Debug.WriteLine(ex.Message);
	}
}

The Arduino client code works though I need modify it so I can do more testing of the initialise method parameter options.

RFM69 hat library Part12A

Posted on by

Enums and Masks

Based on the approach I used in my RFM9X library this refactor adds enumerations and constants for initialising and then accessing the registers of the RFM69CW/RFM69HCW module (based on the Semtech SX1231/SX1231H) .

Adafruit RFM69 Radio Bonnet

There is now a even less code in the Run method in the startup.cs file and the code for configuring the RFM69 is more obvious

public sealed class StartupTask : IBackgroundTask
{
	private const int ResetPin = 25;
	private const int InterruptPin = 22;
	private Rfm69HcwDevice rfm69Device = new Rfm69HcwDevice(ChipSelectPin.CS1, ResetPin, InterruptPin);

	public void Run(IBackgroundTaskInstance taskInstance)
	{
		byte[] syncValues ={0xAA, 0x2D, 0xD4};

		rfm69Device.Initialise(Rfm69HcwDevice.RegOpModeMode.StandBy,
			bitRate: Rfm69HcwDevice.BitRate.bps4K8,
			frequency: 915000000.0, frequencyDeviation: 0X023d,
			dccFrequency: 0x1,rxBwMant: Rfm69HcwDevice.RxBwMant.RxBwMant20, RxBwExp:0x2,
			preambleSize: 16,
			syncSize: 3,
			syncValues: syncValues,
			packetFormat: Rfm69HcwDevice.RegPacketConfig1PacketFormat.VariableLength,
			packetCrc:true
		);

	// RegDioMapping1
	rfm69Device.RegisterManager.WriteByte(0x26, 0x01);

	rfm69Device.RegisterDump();

	while (true)
	{
		byte[] messageBuffer = UTF8Encoding.UTF8.GetBytes("hello world " + DateTime.Now.ToLongTimeString());

		rfm69Device.SendMessage(messageBuffer);

		Debug.WriteLine("{0:HH:mm:ss.fff} Send-Done", DateTime.Now);

		Task.Delay(5000).Wait();
	}
}

The Rasmitic library modifies a number of the default settings (e.g. RegRxBw register) so I had to reverse engineer the values. I also added SendMessage methods for both addressed and un-addressed messages.

Register dump
Register 0x01 - Value 0X04 - Bits 00000100
Register 0x02 - Value 0X00 - Bits 00000000
Register 0x03 - Value 0X1a - Bits 00011010
…
Register 0x4b - Value 0X00 - Bits 00000000
Register 0x4c - Value 0X00 - Bits 00000000
Register 0x4d - Value 0X00 - Bits 00000000
16:52:38.337 Send-Done
16:52:38.456 RegIrqFlags 00001000
16:52:38.472 Transmit-Done
The thread 0xfe4 has exited with code 0 (0x0).
The thread 0x100 has exited with code 0 (0x0).
16:52:43.391 Send-Done
16:52:43.465 RegIrqFlags 00001000
16:52:43.480 Transmit-Done
The thread 0xb94 has exited with code 0 (0x0).
16:52:48.475 Send-Done
16:52:48.550 RegIrqFlags 00001000
16:52:48.563 Transmit-Done
16:52:53.448 RegIrqFlags 01000110
16:52:53 Received 13 byte message Hello world:0
The thread 0x2b4 has exited with code 0 (0x0).
16:52:53.559 Send-Done
16:52:53.633 RegIrqFlags 00001000
16:52:53.648 Transmit-Done
16:52:54.577 RegIrqFlags 01000110
16:52:54 Received 13 byte message Hello world:1
16:52:55.706 RegIrqFlags 01000110
16:52:55 Received 13 byte message Hello world:2
16:52:56.836 RegIrqFlags 01000110
16:52:56 Received 13 byte message Hello world:3
16:52:57.965 RegIrqFlags 01000110
16:52:57 Received 13 byte message Hello world:4
The thread 0x354 has exited with code 0 (0x0).
16:52:58.634 Send-Done
16:52:58.709 RegIrqFlags 00001000
16:52:58.724 Transmit-Done
16:52:59.095 RegIrqFlags 01000110
16:52:59 Received 13 byte message Hello world:5
The program '[3736] backgroundTaskHost.exe' has exited with code -1

The Arduino code works though I need modify it so I can do more testing of the initialise method parameter options.

16:41:03.619 -> RX start
16:41:03.619 -> 0x0: 0x0
16:41:03.654 -> 0x1: 0x10
16:41:03.654 -> 0x2: 0x0
…
16:41:04.310 -> 0x3B: 0x0
16:41:04.310 -> 0x3C: 0x1
16:41:04.344 -> 0x3D: 0x0
16:41:07.228 -> MessageIn:hello world 4:41:07 PM
16:41:12.322 -> MessageIn:hello world 4:41:12 PM
16:41:17.395 -> MessageIn:hello world 4:41:17 PM
16:41:22.448 -> MessageIn:hello world 4:41:22 PM
16:41:27.533 -> MessageIn:hello world 4:41:27 PM
16:41:32.609 -> MessageIn:hello world 4:41:32 PM
16:41:37.673 -> MessageIn:hello world 4:41:37 PM

The Initialise method has a large number of parameters but as most of these have a reasonable default I’m not to concerned.

public void Initialise(RegOpModeMode modeAfterInitialise,
			BitRate bitRate = BitRateDefault,
			ushort frequencyDeviation = frequencyDeviationDefault,
			double frequency = FrequencyDefault,
			ListenModeIdleResolution listenModeIdleResolution = ListenModeIdleResolutionDefault, ListenModeRXTime listenModeRXTime = ListenModeRXTimeDefault, ListenModeCrieria listenModeCrieria = ListenModeCrieriaDefault, ListenModeEnd listenModeEnd = ListenModeEndDefault,
			byte listenCoefficientIdle = ListenCoefficientIdleDefault,
			byte listenCoefficientReceive = ListenCoefficientReceiveDefault,
			bool pa0On = pa0OnDefault, bool pa1On = pa1OnDefaut, bool pa2On = pa2OnDefault, byte outputpower = OutputpowerDefault,
			PaRamp paRamp = PaRampDefault,
			bool ocpOn = OcpOnDefault, byte ocpTrim = OcpTrimDefault,
			LnaZin lnaZin = LnaZinDefault, LnaCurrentGain lnaCurrentGain = LnaCurrentGainDefault, LnaGainSelect lnaGainSelect = LnaGainSelectDefault,
			byte dccFrequency = DccFrequencyDefault, RxBwMant rxBwMant = RxBwMantDefault, byte RxBwExp = RxBwExpDefault,
			byte dccFreqAfc = DccFreqAfcDefault, byte rxBwMantAfc = RxBwMantAfcDefault, byte bxBwExpAfc = RxBwExpAfcDefault,
			ushort preambleSize = PreambleSizeDefault,
			bool syncOn = SyncOnDefault, SyncFifoFileCondition syncFifoFileCondition = SyncFifoFileConditionDefault, byte syncSize = SyncSizeDefault, byte syncTolerance = SyncToleranceDefault, byte[] syncValues = null,
			RegPacketConfig1PacketFormat packetFormat = RegPacketConfig1PacketFormat.FixedLength,
			RegPacketConfig1DcFree packetDcFree = RegPacketConfig1DcFreeDefault,
			bool packetCrc = PacketCrcOnDefault,
			bool packetCrcAutoClearOff = PacketCrcAutoClearOffDefault,
			RegPacketConfig1CrcAddressFiltering packetAddressFiltering = PacketAddressFilteringDefault,
			byte payloadLength = PayloadLengthDefault,
			byte addressNode = NodeAddressDefault, byte addressbroadcast = BroadcastAddressDefault
			)
		{
			RegOpModeModeCurrent = modeAfterInitialise;
			PacketFormat = packetFormat;

			// Strobe Reset pin briefly to factory reset SX1231 chip
			ResetGpioPin.Write(GpioPinValue.High);
			Task.Delay(100);
			ResetGpioPin.Write(GpioPinValue.Low);
			Task.Delay(10);

			// Put the device into sleep mode so registers can be changed
			SetMode(RegOpModeMode.Sleep);

Most of the initialise method follows a similar pattern, checking parameters associated with a Register and only setting it if the cvalues are not all the default

// Configure RF Carrier frequency RegFrMsb, RegFrMid, RegFrLsb
if (frequency != FrequencyDefault)
{
	byte[] bytes = BitConverter.GetBytes((long)(frequency / RH_RFM69HCW_FSTEP));
	RegisterManager.WriteByte((byte)Registers.RegFrfMsb, bytes[2]);
	RegisterManager.WriteByte((byte)Registers.RegFrfMid, bytes[1]);
	RegisterManager.WriteByte((byte)Registers.RegFrfLsb, bytes[0]);
}

Some registers are a bit more complex to configure e.g. RegSyncConfig

// RegSyncConfig
if ((syncOn != SyncOnDefault) ||
	 (syncFifoFileCondition != SyncFifoFileConditionDefault) ||
	 (syncSize != SyncSizeDefault) ||
	 (syncTolerance != SyncToleranceDefault))
{
	byte regSyncConfigValue= 0b00000000;

	if (syncOn)
	{
		regSyncConfigValue |= 0b10000000;
	}
	
	regSyncConfigValue |= (byte)syncFifoFileCondition;

	regSyncConfigValue |= (byte)((syncSize - 1) << 3);
	regSyncConfigValue |= (byte)syncTolerance;
	RegisterManager.WriteByte((byte)Registers.RegSyncConfig, regSyncConfigValue);
}

I have just got to finish the code for RegFifoThresh, RegPacketConfig2 and the RegAesKey1-16 registers.

Other libraries for the RRFM69 support changing configuration while the application is running which significantly increases the complexity and number of test cases. My initial version will only support configuration on start-up.

RFM69 hat library Part11

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RegisterManager Refactor

I had been meaning to refactor the code for accessing the registers of the RFM69CW/RFM69HCW module (based on the Semtech SX1231/SX1231H) registers for a while.

Adafruit RFM69 Radio Bonnet

There is now a lot less code in the startup.cs file and the code for configuring the RFM69 is more obvious

/*
    Copyright ® 2019 July devMobile Software, All Rights Reserved

	 MIT License

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    in the Software without restriction, including without limitation the rights
	 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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    furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included in all
	 copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	 SOFTWARE

 */
namespace devMobile.IoT.Rfm69Hcw.RefactorRegisterManager
{
	using System;
	using System.Diagnostics;
	using System.Text;
	using System.Threading.Tasks;
	using Windows.ApplicationModel.Background;
	using Windows.Devices.Gpio;

	sealed class Rfm69HcwDevice
	{
		private GpioPin InterruptGpioPin = null;
		public RegisterManager RegisterManager = null; // Future refactor this will be made private

		public Rfm69HcwDevice(ChipSelectPin chipSelectPin, int resetPin, int interruptPin)
		{
			RegisterManager = new RegisterManager(chipSelectPin);

			// Factory reset pin configuration
			GpioController gpioController = GpioController.GetDefault();
			GpioPin resetGpioPin = gpioController.OpenPin(resetPin);
			resetGpioPin.SetDriveMode(GpioPinDriveMode.Output);
			resetGpioPin.Write(GpioPinValue.High);
			Task.Delay(100);
			resetGpioPin.Write(GpioPinValue.Low);
			Task.Delay(10);

			// Interrupt pin for RX message & TX done notification 
			InterruptGpioPin = gpioController.OpenPin(interruptPin);
			resetGpioPin.SetDriveMode(GpioPinDriveMode.Input);

			InterruptGpioPin.ValueChanged += InterruptGpioPin_ValueChanged;
		}

		private void InterruptGpioPin_ValueChanged(GpioPin sender, GpioPinValueChangedEventArgs args)
		{
			if (args.Edge != GpioPinEdge.RisingEdge)
			{
				return;
			}

			byte irqFlags = RegisterManager.ReadByte(0x28); // RegIrqFlags2
			Debug.WriteLine("{0:HH:mm:ss.fff} RegIrqFlags {1}", DateTime.Now, Convert.ToString((byte)irqFlags, 2).PadLeft(8, '0'));
			if ((irqFlags & 0b00000100) == 0b00000100)  // PayLoadReady set
			{
				// Read the length of the buffer
				byte numberOfBytes = RegisterManager.ReadByte(0x0);

				// Allocate buffer for message
				byte[] messageBytes = new byte[numberOfBytes];

				for (int i = 0; i < numberOfBytes; i++)
				{
					messageBytes[i] = RegisterManager.ReadByte(0x00); // RegFifo
				}

				string messageText = UTF8Encoding.UTF8.GetString(messageBytes);
				Debug.WriteLine("{0:HH:mm:ss} Received {1} byte message {2}", DateTime.Now, messageBytes.Length, messageText);
			}

			if ((irqFlags & 0b00001000) == 0b00001000)  // PacketSent set
			{
				RegisterManager.WriteByte(0x01, 0b00010000); // RegOpMode set ReceiveMode
				Debug.WriteLine("{0:HH:mm:ss.fff} Transmit-Done", DateTime.Now);
			}
		}

		public void RegisterDump()
		{
			RegisterManager.Dump(0x0, 0x40);
		}
	}
	

	public sealed class StartupTask : IBackgroundTask
	{
		private const int ResetPin = 25;
		private const int InterruptPin = 22;
		private Rfm69HcwDevice rfm69Device = new Rfm69HcwDevice(ChipSelectPin.CS1, ResetPin, InterruptPin);

		const double RH_RF6M9HCW_FXOSC = 32000000.0;
		const double RH_RFM69HCW_FSTEP = RH_RF6M9HCW_FXOSC / 524288.0;

		public void Run(IBackgroundTaskInstance taskInstance)
		{
			//rfm69Device.RegisterDump();

			// regOpMode standby
			rfm69Device.RegisterManager.WriteByte(0x01, 0b00000100);

			// BitRate MSB/LSB
			rfm69Device.RegisterManager.WriteByte(0x03, 0x34);
			rfm69Device.RegisterManager.WriteByte(0x04, 0x00);

			// Frequency deviation
			rfm69Device.RegisterManager.WriteByte(0x05, 0x02);
			rfm69Device.RegisterManager.WriteByte(0x06, 0x3d);

			// Calculate the frequency accoring to the datasheett
			byte[] bytes = BitConverter.GetBytes((uint)(915000000.0 / RH_RFM69HCW_FSTEP));
			Debug.WriteLine("Byte Hex 0x{0:x2} 0x{1:x2} 0x{2:x2} 0x{3:x2}", bytes[0], bytes[1], bytes[2], bytes[3]);
			rfm69Device.RegisterManager.WriteByte(0x07, bytes[2]);
			rfm69Device.RegisterManager.WriteByte(0x08, bytes[1]);
			rfm69Device.RegisterManager.WriteByte(0x09, bytes[0]);

			// RegRxBW
			rfm69Device.RegisterManager.WriteByte(0x19, 0x2a);

			// RegDioMapping1
			rfm69Device.RegisterManager.WriteByte(0x26, 0x01);

			// Setup preamble length to 16 (default is 3) RegPreambleMsb RegPreambleLsb
			rfm69Device.RegisterManager.WriteByte(0x2C, 0x0);
			rfm69Device.RegisterManager.WriteByte(0x2D, 0x10);

			// RegSyncConfig Set the Sync length and byte values SyncOn + 3 custom sync bytes
			rfm69Device.RegisterManager.WriteByte(0x2e, 0x90);

			// RegSyncValues1 thru RegSyncValues3
			rfm69Device.RegisterManager.WriteByte(0x2f, 0xAA);
			rfm69Device.RegisterManager.WriteByte(0x30, 0x2D);
			rfm69Device.RegisterManager.WriteByte(0x31, 0xD4);

			// RegPacketConfig1 Variable length with CRC on
			rfm69Device.RegisterManager.WriteByte(0x37, 0x90);

			rfm69Device.RegisterDump();

			while (true)
			{
				// Standby mode while loading message into FIFO
				rfm69Device.RegisterManager.WriteByte(0x01, 0b00000100);

				byte[] messageBuffer = UTF8Encoding.UTF8.GetBytes("hello world " + DateTime.Now.ToLongTimeString());
				rfm69Device.RegisterManager.WriteByte(0x0, (byte)messageBuffer.Length);
				rfm69Device.RegisterManager.Write(0x0, messageBuffer);

				// Transmit mode once FIFO loaded
				rfm69Device.RegisterManager.WriteByte(0x01, 0b00001100);

				Debug.WriteLine("{0:HH:mm:ss.fff} Send-Done", DateTime.Now);

				Task.Delay(5000).Wait();
			}
		}
	}
}

I’ll modify the constructor reset pin support to see if I can get the Seegel Systeme hat working.

Register dump
Register 0x00 - Value 0X00 - Bits 00000000
Register 0x01 - Value 0X04 - Bits 00000100
Register 0x02 - Value 0X00 - Bits 00000000
Register 0x03 - Value 0X34 - Bits 00110100
…
Register 0x3e - Value 0X00 - Bits 00000000
Register 0x3f - Value 0X00 - Bits 00000000
Register 0x40 - Value 0X00 - Bits 00000000
19:58:52.828 Send-Done
19:58:53.022 RegIrqFlags 00001000
19:58:53.036 Transmit-Done
19:58:54.188 RegIrqFlags 01000110
19:58:54 Received 14 byte message Hello world:1
The thread 0xa10 has exited with code 0 (0x0).
The thread 0xf90 has exited with code 0 (0x0).
19:58:57.652 RegIrqFlags 01000110
19:58:57 Received 14 byte message Hello world:2
19:58:57.892 Send-Done
19:58:58.039 RegIrqFlags 00001000
19:58:58.053 Transmit-Done
19:59:01.115 RegIrqFlags 01000110
19:59:01 Received 14 byte message Hello world:3
19:59:02.936 Send-Done
19:59:03.083 RegIrqFlags 00001000
19:59:03.096 Transmit-Done
19:59:04.577 RegIrqFlags 01000110
19:59:04 Received 14 byte message Hello world:4
The thread 0xa5c has exited with code 0 (0x0).
19:59:08.001 Send-Done
19:59:08.122 RegIrqFlags 01001000
19:59:08.139 Transmit-Done
19:59:11.504 RegIrqFlags 01000110
19:59:11 Received 14 byte message Hello world:6
The thread 0xb18 has exited with code 0 (0x0).
19:59:13.079 Send-Done
19:59:13.226 RegIrqFlags 00001000
19:59:13.240 Transmit-Done
19:59:14.966 RegIrqFlags 01000110
19:59:14 Received 14 byte message Hello world:7

Based how my rate of progress improved when I did this on the RFM9X library I really should have done this much earlier.