Easy Sensors Wireless field gateway Arduino Nano client

After not much development on my nrf24L01 AdaFruit.IO and Azure IOT Hub field gateways for a while some new nRF24L01 devices arrived in the post last week.

This sample client is an Arduino Nano clone with an Arduino Nano radio shield for NRF24L01+.

I use the shield’s onboard SHA204A crypto and authentication chip, and a Seeedstudio Temperature & Humidity sensor with the data uploaded to adafruit.io.

/*
  Copyright ® 2018 September devMobile Software, All Rights Reserved

  THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
  KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
  IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR
  PURPOSE.

  You can do what you want with this code, acknowledgment would be nice.

  http://www.devmobile.co.nz

*/
#include
#include
#include 

// RF24 radio( ChipeEnable , ChipSelect )
RF24 radio(9, 10);
const byte FieldGatewayChannel = 15 ;
const byte FieldGatewayAddress[] = {"Base1"};
const rf24_datarate_e RadioDataRate = RF24_250KBPS;
const rf24_pa_dbm_e RadioPALevel = RF24_PA_HIGH;

// Payload configuration
const int PayloadSizeMaximum = 32 ;
char payload[PayloadSizeMaximum] = "";
const byte DeviceIdPlusCsvSensorReadings = 1 ;
const byte SensorReadingSeperator = ',' ;

// ATSHA204 secure authentication, validation with crypto and hashing (only using for unique serial number)
atsha204Class sha204(A3);
const int DeviceSerialNumberLength = 9 ;
uint8_t deviceSerialNumber[DeviceSerialNumberLength] = {""};
const int LoopSleepDelaySeconds = 10 ;

void setup()
{
  Serial.begin(9600);
  Serial.println("Setup called");

  // Retrieve the serial number then display it nicely
  sha204.getSerialNumber(deviceSerialNumber);

  Serial.print("SNo:");
  for (int i = 0; i < sizeof( deviceSerialNumber) ; i++)
  {
    // Add a leading zero
    if ( deviceSerialNumber[i] < 16)
    {
      Serial.print("0");
    }
    Serial.print(deviceSerialNumber[i], HEX);
    Serial.print(" ");
  }

  Serial.println();

  // Configure the Seeedstudio TH02 temperature & humidity sensor
  Serial.println("TH02 setup");
  TH02.begin();
  delay(100);

  // Configure the nRF24 module
  Serial.println("nRF24 setup");
  radio.begin();
  radio.setChannel(FieldGatewayChannel);
  radio.openWritingPipe(FieldGatewayAddress);
  radio.setDataRate(RadioDataRate) ;
  radio.setPALevel(RadioPALevel);
  radio.enableDynamicPayloads();

  Serial.println("Setup done");
}

void loop()
{
  int payloadLength = 0 ;
  float temperature ;
  float humidity ;

  Serial.println("Loop called");
  memset( payload, 0, sizeof( payload));

  // prepare the payload header with PayloadMessageType (top nibble) and DeviceID length (bottom nibble)
  payload[0] = (DeviceIdPlusCsvSensorReadings &lt;<span id="mce_SELREST_start" style="overflow:hidden;line-height:0;"></span>&lt; 4) | sizeof(deviceSerialNumber) ;
  payloadLength += 1;

  // Copy the device serial number into the payload
  memcpy( &amp;payload[payloadLength], deviceSerialNumber, sizeof( deviceSerialNumber));
  payloadLength += sizeof( deviceSerialNumber) ;

  // Read the temperature, humidity &amp; battery voltage values then display nicely
  temperature = TH02.ReadTemperature();
  Serial.print(&quot;T:&quot;);
  Serial.print( temperature, 1 ) ;
  Serial.print( &quot;C&quot; ) ;

  humidity = TH02.ReadHumidity();
  Serial.print(&quot; H:&quot;);
  Serial.print( humidity, 0 ) ;
  Serial.println( &quot;%&quot; ) ;

  // Copy the temperature into the payload
  payload[ payloadLength] = &#039;t&#039;;
  payloadLength += 1 ;
  dtostrf(temperature, 6, 1, &amp;payload[payloadLength]);
  payloadLength += 6;

  payload[ payloadLength] = &#039;,&#039;;
  payloadLength += 1 ;

  // Copy the humidity into the payload
  payload[ payloadLength] = &#039;h&#039;;
  payloadLength += 1 ;
  dtostrf(humidity, 4, 0, &amp;payload[payloadLength]);
  payloadLength += 4;

  // Powerup the nRF24 chipset then send the payload to base station
  Serial.print( &quot;Payload length:&quot;);
  Serial.println( payloadLength );

  Serial.println( &quot;nRF24 write&quot; ) ;
  boolean result = radio.write(payload, payloadLength);
  if (result)
    Serial.println(&quot;Write Ok...&quot;);
  else
    Serial.println(&quot;Write failed.&quot;);

  Serial.println(&quot;Loop done&quot;);
  delay(LoopSleepDelaySeconds * 1000l);
}

Arduino monitor output

NanoArduinoNrf24

Prototype hardware

ArduinoNanonRF24

Bill of materials (prices as at Sep 2018)

  • Arduino Nano clone USD4.70
  • Easy Sensors Arduino Nano Radio Shield for nRF24L01 USD13
  • Seeedstudio Temperature and Humidity Sensor Pro USD11.50
  • Seeedstudio 4 pin Male Jumper to Grove 4 pin Conversion Cable USD2.90

Adafruit.IO temperature display when I moved the sensor outside.

NanoNrf24

Rfm9xLoRaDevice NetMF SNR and RSSI

The signal to noise Ratio (SNR) and Received Signal Strength Indication(RSSI) for inbound messages required reading values from three registers
•RegPktSnrValue
•RegPktRssiValue
•RegRssiValue

I had to modify the OnDataRecievedHandler method signature so the values could be returned

 public delegate void OnDataRecievedHandler(float packetSnr, int packetRssi, int rssi, byte[] data);

I was inspired by the RSSI adjustment approach used in the Arduino-LoRa library

// Get the RSSI HF vs. LF port adjustment section 5.5.5 RSSI and SNR in LoRa Mode
float packetSnr = this.Rfm9XLoraModem.ReadByte((byte)Registers.RegPktSnrValue) * 0.25f;

int rssi = this.Rfm9XLoraModem.ReadByte((byte)Registers.RegRssiValue);
if (Frequency > RFMidBandThreshold)
{
  rssi = RssiAdjustmentHF + rssi;
}
else
{
  rssi = RssiAdjustmentLF + rssi;
}

int packetRssi = this.Rfm9XLoraModem.ReadByte((byte)Registers.RegPktRssiValue);
if (Frequency > RFMidBandThreshold)
{
  packetRssi = RssiAdjustmentHF + packetRssi;
}
else
{
  packetRssi = RssiAdjustmentLF + packetRssi;
}

OnDataReceived?.Invoke( packetSnr, packetRssi, rssi, messageBytes);

The values displayed in the Rfm9xLoRaDeviceClient application looked reasonable, but will need further checking

00:06:14-Rfm9X PacketSnr 9.8 Packet RSSI -47dBm RSSI -111dBm = 28 byte message "Hello W10 IoT Core LoRa! 182"
Sending 20 bytes message Hello NetMF LoRa! 38
Transmit-Done
00:06:24-Rfm9X PacketSnr 9.8 Packet RSSI -48dBm RSSI -111dBm = 28 byte message "Hello W10 IoT Core LoRa! 181"
Sending 20 bytes message Hello NetMF LoRa! 39
Transmit-Done
00:06:34-Rfm9X PacketSnr 9.8 Packet RSSI -47dBm RSSI -112dBm = 28 byte message "Hello W10 IoT Core LoRa! 180"
Sending 20 bytes message Hello NetMF LoRa! 40
Transmit-Done
00:06:44-Rfm9X PacketSnr 10.0 Packet RSSI -48dBm RSSI -111dBm = 28 byte message "Hello W10 IoT Core LoRa! 179"

 

Re-reading the SX1276 datasheet

I sat down and read the Semtech SX1276 datasheet paying close attention to any references to CRCs and headers. Then to test some ideas I modified my Receive Basic test harness to see if I could reliably reproduce the problem with my stress test harness.LoRaStress2

public sealed class StartupTask : IBackgroundTask
	{
		private const int ChipSelectLine = 25;
		private const int ResetLine = 17;
		private Rfm9XDevice rfm9XDevice = new Rfm9XDevice(ChipSelectLine, ResetLine);

		public void Run(IBackgroundTaskInstance taskInstance)
		{
			// Put device into LoRa + Sleep mode
			rfm9XDevice.RegisterWriteByte(0x01, 0b10000000); // RegOpMode 

			// Set the frequency to 915MHz
			byte[] frequencyWriteBytes = { 0xE4, 0xC0, 0x00 }; // RegFrMsb, RegFrMid, RegFrLsb
			rfm9XDevice.RegisterWrite(0x06, frequencyWriteBytes);

			rfm9XDevice.RegisterWriteByte(0x0F, 0x0); // RegFifoRxBaseAddress 

			rfm9XDevice.RegisterWriteByte(0x01, 0b10000101); // RegOpMode set LoRa & RxContinuous

			while (true)
			{
				// Wait until a packet is received, no timeouts in PoC
				Debug.WriteLine("Receive-Wait");
				byte IrqFlags = rfm9XDevice.RegisterReadByte(0x12); // RegIrqFlags
				while ((IrqFlags & 0b01000000) == 0)  // wait until RxDone cleared
				{
					Task.Delay(20).Wait();
					IrqFlags = rfm9XDevice.RegisterReadByte(0x12); // RegIrqFlags
					Debug.Write(".");
				}
				Debug.WriteLine("");

				if ((IrqFlags & 0b00100000) == 0b00100000)
				{
					Debug.WriteLine("Payload CRC error");
				}

				byte regHopChannel = rfm9XDevice.RegisterReadByte(0x1C);
				Debug.WriteLine(string.Format("regHopChannel {0}", Convert.ToString((byte)regHopChannel, 2).PadLeft(8, '0')));

				byte currentFifoAddress = rfm9XDevice.RegisterReadByte(0x10); // RegFifiRxCurrent
				rfm9XDevice.RegisterWriteByte(0x0d, currentFifoAddress); // RegFifoAddrPtr*
				byte numberOfBytes = rfm9XDevice.RegisterReadByte(0x13); // RegRxNbBytes

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

				for (int i = 0; i < numberOfBytes; i++)
				{
					messageBytes[i] = rfm9XDevice.RegisterReadByte(0x00); // RegFifo
				}
				rfm9XDevice.RegisterWriteByte(0x12, 0xff); // RegIrqFlags clear all the bits

				string messageText = UTF8Encoding.UTF8.GetString(messageBytes);
				Debug.WriteLine("Received {0} byte message {1}", messageBytes.Length, messageText);
				Debug.WriteLine(string.Format("RegIrqFlags {0}", Convert.ToString((byte)IrqFlags, 2).PadLeft(8, '0')));
				Debug.WriteLine("Receive-Done");
			}
		}
	}

The RegHopChannel register has a flag indicating whether there was a CRC extracted from the packet header.

regHopChannel 00000000
Received 23 byte message 1 Hello Arduino LoRa! 1
RegIrqFlags 01010000
Receive-Done
Receive-Wait
…………………………..
regHopChannel 00000000
Received 23 byte message 1 Hello Arduino LoRa! 2
RegIrqFlags 01010000
Receive-Done
Receive-Wait
……………………………
regHopChannel 00000000
Received 23 byte message 1 Hello Arduino LoRa! 3
RegIrqFlags 01010000
Receive-Done
Receive-Wait

I then modified my Arduino-LoRa library based client to include a CRC

void setup() {
  Serial.begin(9600);                   // initialize serial
  while (!Serial);

  Serial.println("LoRa Duplex - Set sync word");

  // override the default CS, reset, and IRQ pins (optional)
  LoRa.setPins(csPin, resetPin, irqPin);// set CS, reset, IRQ pin

  if (!LoRa.begin(915E6)) {             // initialize ratio at 915 MHz
    Serial.println("LoRa init failed. Check your connections.");
    while (true);                       // if failed, do nothing
  }

  LoRa.enableCrc();  // BHL This was my change

  LoRa.setSyncWord(0x12);           // ranges from 0-0xFF, default 0x34, see API docs

  LoRa.dumpRegisters(Serial);
  Serial.println("LoRa init succeeded.");
}

void loop() {
  if (millis() - lastSendTime > interval) {
    String message = "5 Hello Arduino LoRa! ";   // send a message
    message += msgCount;
    sendMessage(message);
    Serial.println("Sending " + message);
    lastSendTime = millis();            // timestamp the message
    //interval = random(2000) + 1000;    // 2-3 seconds
    interval = 1000;
  }

  // parse for a packet, and call onReceive with the result:
  onReceive(LoRa.parsePacket());
}

void sendMessage(String outgoing) {
  LoRa.beginPacket();                   // start packet
  LoRa.print(outgoing);                 // add payload
  LoRa.endPacket();                     // finish packet and send it
  msgCount++;                           // increment message ID
}

void onReceive(int packetSize) {
  if (packetSize == 0) return;          // if there's no packet, return

  // read packet header bytes:
  String incoming = "";

  while (LoRa.available()) {
    incoming += (char)LoRa.read();
  }

  Serial.println("Message: " + incoming);
  Serial.println("RSSI: " + String(LoRa.packetRssi()));
  Serial.println("Snr: " + String(LoRa.packetSnr()));
  Serial.println();
}

When I powered up a single client and the payload had a CRC

...............................
regHopChannel 01000000
Received 23 byte message 6 Hello Arduino LoRa! 6
RegIrqFlags 01010000
Receive-Done
Receive-Wait
.................................
regHopChannel 01000000
Received 23 byte message 6 Hello Arduino LoRa! 7
RegIrqFlags 01010000
Receive-Done
Receive-Wait
.................................
regHopChannel 01000000
Received 23 byte message 6 Hello Arduino LoRa! 8
RegIrqFlags 01010000
Receive-Done
Receive-Wait
...............................

Then when I increased the number of clients I started getting corrupted messages with CRC errors.

Received 24 byte message 6 Hello Arduino LoRa! 32
RegIrqFlags 01010000
Receive-Done
Receive-Wait
...............
regHopChannel 01000001
Received 25 byte message 8 Hello Arduino LoRa! 114
RegIrqFlags 01010000
Receive-Done
Receive-Wait
Payload CRC error
regHopChannel 01000000
Received 24 byte message s��=��(��p�^j�\ʏ�����
RegIrqFlags 01100000
Receive-Done
Receive-Wait
.............
regHopChannel 01000000
Received 24 byte message 6 Hello Arduino LoRa! 33
RegIrqFlags 01010000
Receive-Done
Receive-Wait
...............
regHopChannel 01000001
Received 25 byte message 8 Hello Arduino LoRa! 115
RegIrqFlags 01010000
Receive-Done
Receive-Wait

I need to do some more testing but now I think the problem was the RegIrqFlags PayloadCRCError flag was never going to get set because there was no CRC on the payload.

Azure Meetup Christchurch notes

For the people who came to my Azure meetup session this evening

Sources of sensors and development boards

http://www.adafruit.com
http://www.elecrow.com (watering kits)
http://www.ingenuitymicro.com (NZ based dev boards)
http://www.netduino.com (.NetMF development boards)
http://www.makerfabs.com
http://www.seeedstudio.com
http://www.tindie.com

nRF24Shields for RPI devices
http://www.tindie.com/products/ceech/new-raspberry-pi-to-nrf24l01-shield/

nRF24Shields for *duino devices in AU
embeddedcoolness.com

Raspberry PI Source in CHC
http://www.wavetech.co.nz

RFM69 & LoRa Modules
http://www.wisen.com.au

local sensor and device resellers quick turnaround
http://www.mindkits.co.nz
http://www.nicegear.co.nz

http://www.diyelectricskateboard.com

The watch development platform
http://www.hexiwear.com

http://www.gowifi.co.nz (Antennas & other wireless kit based in Rangiora)

my projects
http://www.hackster.io/KiwiBryn
io.adafruit.com/BrynHLewis/dashboards/home-environment

Wireless field gateway devDuino client V1

This client is a devDuino V2.2 device with an AdaFruit AM2315 temperature & humidity sensor. This sensor is powered by two AAA batteries and has an on-board support for unique device identification and encryption.

In this first iteration the focus was accessing the SHA204A crypto and authentication chip, the AM2315 sensor and message payload assembly. Reducing the power consumption, improving reliability etc. will be covered in future posts.

/*
Copyright ® 2018 Jan devMobile Software, All Rights Reserved

THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR
PURPOSE.

You can do what you want with this code, acknowledgment would be nice.

http://www.devmobile.co.nz

*/
#include <RF24.h>
#include <Adafruit_AM2315.h>
#include <sha204_library.h>

// nRF24L01 ISM wireless module setup
RF24 radio(7,6);
const int nRFPayloadSize = 32 ;
char payload[nRFPayloadSize] = "";
const byte FieldGatewayAddress[5] = "Base1";
const byte FieldGatewayChannel = 10 ;
const rf24_pa_dbm_e RadioPALevel = RF24_PA_MAX;
const rf24_datarate_e RadioDataRate = RF24_250KBPS; 

// ATSHA204 secure authentication, validation with crypto and hashing (initially only used for unique serial number)
atsha204Class sha204(A2);
const int SerialNumberLength = 9 ;
uint8_t serialNumber[SerialNumberLength];

// AM2315 I2C Outdoors temperature and humdity sensor
Adafruit_AM2315 am2315;

const int LoopSleepDelay = 30000 ;

void setup()
{
  Serial.begin(9600);
  Serial.println("Setup called");

  // Retrieve the serial number then display it nicely
  sha204.getSerialNumber(serialNumber);

  Serial.print("SNo:");
  for (int i=0; i<SerialNumberLength; i++)
  {
    // Add a leading zero
    if ( serialNumber[i] < 16)
    {
      Serial.print("0");
    }
    Serial.print(serialNumber[i], HEX);
    Serial.print(" ");
  }
  Serial.println(); 

  // Configure the AM2315 temperature & humidity sensor
  Serial.println("AM2315 setup");
  am2315.begin();

  // Configure the nRF24 module
  Serial.println("nRF24 setup");
  radio.begin();
  radio.setPALevel(RadioPALevel);
  radio.setDataRate(RadioDataRate) ;
  radio.setChannel(FieldGatewayChannel);
  radio.enableDynamicPayloads();
  radio.openWritingPipe(FieldGatewayAddress);

  delay(1000);

  Serial.println("Setup done");
}

void loop()
{
  float temperature ;
  float humidity ;
  float batteryVoltage ;

  Serial.println("Loop called");
  memset( payload, 0, sizeof( payload));

  // prepare the payload header
  int payloadLength = 0 ;
  payload[0] = 1 ; // Sensor device unique ID header with CSV payload
  payloadLength += 1;

  // Copy the ATSHA204 device serial number into the payload
  payload[1] = SerialNumberLength ;
  payloadLength += 1;
  memcpy( &payload[payloadLength], serialNumber, SerialNumberLength);
  payloadLength += SerialNumberLength ;

  // Read the temperature, humidity & battery voltage values then display nicely
  am2315.readTemperatureAndHumidity(temperature, humidity);
  Serial.print("T:");
  Serial.print( temperature, 1 ) ;
  Serial.print( "C" ) ;

  Serial.print(" H:");
  Serial.print( humidity, 0 ) ;
  Serial.print( "%" ) ;

  batteryVoltage = readVcc() / 1000.0 ;
  Serial.print(" B:");
  Serial.print( batteryVoltage, 2 ) ;
  Serial.println( "V" ) ;

  // Copy the temperature into the payload
  payload[ payloadLength] = 'T';
  payloadLength += 1 ;
  dtostrf(temperature, 6, 1, &payload[payloadLength]);
  payloadLength += 6;
  payload[ payloadLength] = ',';
  payloadLength += 1 ;

  // Copy the humidity into the payload
  payload[ payloadLength] = 'H';
  payloadLength += 1 ;
  dtostrf(humidity, 4, 0, &payload[payloadLength]);
  payloadLength += 4;
  payload[ payloadLength] = ',';
  payloadLength += 1 ;

  // Copy the battery voltage into the payload
  payload[ payloadLength] = 'V';
  payloadLength += 1 ;

  dtostrf(batteryVoltage, 5, 2, &payload[payloadLength]);
  payloadLength += 5;

  // Powerup the nRF24 chipset then send the payload to base station
  Serial.print( "Payload length:");
  Serial.println( payloadLength );

  radio.powerUp();
  delay(500);

  Serial.println( "nRF24 write" ) ;
  boolean result = radio.write(payload, payloadLength);
  if (result)
    Serial.println("Write Ok...");
  else
    Serial.println("Write failed.");

 Serial.println( "nRF24 power down" ) ;
 radio.powerDown();

 delay(LoopSleepDelay);
}

Arduino monitor output

devDuinoAM2315V1Output

Prototype hardware

devDuinoAM2315V1Bill of materials (prices as at Jan 2018)

  • devDuino V2.2 USD18
  • AdaFruit AM2315 USD30
  • Grove – 5cm buckled cable USD1.90
  • Grove – Screw Terminal USD2.90
  • 10K resistors x 2

RaspberyPI UWP application diagnostic output

Interrupt Triggered: RisingEdge
Interrupt Triggered: FallingEdge
09:39:03 Address 01-23-32-66-C6-FE-0B-8D-EE Length 9 Payload T  25.0,H  48,V 3.31 Length 20
 Sensor 01-23-32-66-C6-FE-0B-8D-EE-T Value 25.0
 Sensor 01-23-32-66-C6-FE-0B-8D-EE-H Value 48
 Sensor 01-23-32-66-C6-FE-0B-8D-EE-V Value 3.31
Interrupt Triggered: RisingEdge
Interrupt Triggered: FallingEdge
09:39:33 Address 01-23-32-66-C6-FE-0B-8D-EE Length 9 Payload T  24.9,H  48,V 3.30 Length 20
 Sensor 01-23-32-66-C6-FE-0B-8D-EE-T Value 24.9
 Sensor 01-23-32-66-C6-FE-0B-8D-EE-H Value 48
 Sensor 01-23-32-66-C6-FE-0B-8D-EE-V Value 3.30
Interrupt Triggered: RisingEdge
Interrupt Triggered: FallingEdge
09:40:04 Address 01-23-32-66-C6-FE-0B-8D-EE Length 9 Payload T  24.9,H  48,V 3.31 Length 20
 Sensor 01-23-32-66-C6-FE-0B-8D-EE-T Value 24.9
 Sensor 01-23-32-66-C6-FE-0B-8D-EE-H Value 48
 Sensor 01-23-32-66-C6-FE-0B-8D-EE-V Value 3.31
Interrupt Triggered: RisingEdge

nRF24 Windows 10 IoT Core Background Task

First step is to build a basic Windows 10 IoT Core background task which can receive and display messages sent from a variety of devices across an nRF24L01 wireless link.

If you create a new “Windows IoT Core” “Background Application” project then copy this code into StartupTasks.cs the namespace has to be changed in the C# file, project properties\library\Default namespace and “Package.appxmanifest”\declarations\Entry Point.

/*

Copyright ® 2017 December devMobile Software, All Rights Reserved

THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR
PURPOSE.

http://www.devmobile.co.nz

*/
using System;
using System.Diagnostics;
using System.Text;
using Radios.RF24;
using Windows.ApplicationModel.Background;

namespace devmobile.IoTCore.nRF24BackgroundTask
{
    public sealed class StartupTask : IBackgroundTask
    {
      private const byte ChipEnablePin = 25;
      private const byte ChipSelectPin = 0;
      private const byte nRF24InterruptPin = 17;
      private const string BaseStationAddress = "Base1";
      private const byte nRF24Channel = 10;
      private RF24 Radio = new RF24();
      private BackgroundTaskDeferral deferral;

      public void Run(IBackgroundTaskInstance taskInstance)
        {
         Radio.OnDataReceived += Radio_OnDataReceived;
         Radio.OnTransmitFailed += Radio_OnTransmitFailed;
         Radio.OnTransmitSuccess += Radio_OnTransmitSuccess;

         Radio.Initialize(ChipEnablePin, ChipSelectPin, nRF24InterruptPin);
         Radio.Address = Encoding.UTF8.GetBytes(BaseStationAddress);
         Radio.Channel = nRF24Channel;
         Radio.PowerLevel = PowerLevel.High;
         Radio.DataRate = DataRate.DR250Kbps;
         Radio.IsEnabled = true;

         Debug.WriteLine("Address: " + Encoding.UTF8.GetString(Radio.Address));
         Debug.WriteLine("PA: " + Radio.PowerLevel);
         Debug.WriteLine("IsAutoAcknowledge: " + Radio.IsAutoAcknowledge);
         Debug.WriteLine("Channel: " + Radio.Channel);
         Debug.WriteLine("DataRate: " + Radio.DataRate);
         Debug.WriteLine("IsDynamicAcknowledge: " + Radio.IsDyanmicAcknowledge);
         Debug.WriteLine("IsDynamicPayload: " + Radio.IsDynamicPayload);
         Debug.WriteLine("IsEnabled: " + Radio.IsEnabled);
         Debug.WriteLine("Frequency: " + Radio.Frequency);
         Debug.WriteLine("IsInitialized: " + Radio.IsInitialized);
         Debug.WriteLine("IsPowered: " + Radio.IsPowered);

         deferral = taskInstance.GetDeferral();

         Debug.WriteLine("Run completed");
      }

      private void Radio_OnDataReceived(byte[] data)
      {
         // Display as Unicode
         string unicodeText = Encoding.UTF8.GetString(data);
         Debug.WriteLine("Unicode - Payload Length {0} Unicode Length {1} Unicode text {2}", data.Length, unicodeText.Length, unicodeText);

         // display as hex
         Debug.WriteLine("Hex - Length {0} Payload {1}", data.Length, BitConverter.ToString(data));
      }

      private void Radio_OnTransmitSuccess()
      {
         Debug.WriteLine("Transmit Succeeded!");
      }

      private void Radio_OnTransmitFailed()
      {
         Debug.WriteLine("Transmit Failed!");
      }
   }
}

This was displayed in the output window of Visual Studio

Address: Base1
PA: 15
IsAutoAcknowledge: True
Channel: 10
DataRate: DR250Kbps
IsDynamicAcknowledge: False
IsDynamicPayload: True
IsEnabled: True
Frequency: 2410
IsInitialized: True
IsPowered: True
Run completed

Interrupt Triggered: FallingEdge
Unicode – Payload Length 19 Unicode Length 19 Unicode text T  23.8,H  73,V 3.26
Hex – Length 19 Payload 54-20-32-33-2E-38-2C-48-20-20-37-33-2C-56-20-33-2E-32-36
Interrupt Triggered: RisingEdge

Note the odd formatting of the Temperature and humidity values which is due to the way dtostrf function in the Atmel AVR library works.

Also noticed the techfooninja nRF24 library has configurable output power level which I will try to retrofit onto the Gralin NetMF library.

Next, several simple Arduino, devDuino V2.2, Seeeduino V4.2 and Netduino 2/3 clients (plus possibly some others)

nRF24 Windows 10 IoT Core Test Harness

After modifying the Raspbery PI nRF24L01 shields I built a single page single button Universal Windows Platforms(UWP) test harness (using the techfooninja RF24 library) to check everything was working as expected.

I used a couple of Netduinos and Raspbery PI devices to as test clients.

public sealed partial class MainPage : Page
{
   private const byte ChipEnablePin = 25;
   private const byte ChipSelectPin = 0;
   private const byte InterruptPin = 17;
   private const byte Channel = 10;
   private RF24 radio;

   public MainPage()
   {
      this.InitializeComponent();

      this.radio = new RF24();

      this.radio.OnDataReceived += this.Radio_OnDataReceived;
      this.radio.OnTransmitFailed += this.Radio_OnTransmitFailed;
      this.radio.OnTransmitSuccess += this.Radio_OnTransmitSuccess;

      this.radio.Initialize(ChipEnablePin, ChipSelectPin, InterruptPin);
      this.radio.Address = Encoding.UTF8.GetBytes("Base1");
      this.radio.Channel = Channel;
      this.radio.PowerLevel = PowerLevel.Low;
      this.radio.DataRate = DataRate.DR250Kbps;

      this.radio.IsEnabled = true;

      Debug.WriteLine("Address: " + Encoding.UTF8.GetString(this.radio.Address));
      Debug.WriteLine("Channel: " + this.radio.Channel);
      Debug.WriteLine("DataRate: " + this.radio.DataRate);
      Debug.WriteLine("PA: " + this.radio.PowerLevel);
      Debug.WriteLine("IsAutoAcknowledge: " + this.radio.IsAutoAcknowledge);
      Debug.WriteLine("IsDynamicAcknowledge: " + this.radio.IsDynamicAcknowledge);
      Debug.WriteLine("IsDynamicPayload: " + this.radio.IsDynamicPayload);
      Debug.WriteLine("IsEnabled: " + this.radio.IsEnabled);
      Debug.WriteLine("IsInitialized: " + this.radio.IsInitialized);
      Debug.WriteLine("IsPowered: " + this.radio.IsPowered);
   }

   private void Radio_OnDataReceived(byte[] data)
   {
     string dataUTF8 = Encoding.UTF8.GetString(data);

     Debug.WriteLine(string.Format("Received: {0}", dataUTF8));
   }

   private void buttonSend_Click(object sender, Windows.UI.Xaml.RoutedEventArgs e)
   {
      this.radio.SendTo(Encoding.UTF8.GetBytes("Duino"), Encoding.UTF8.GetBytes(DateTime.UtcNow.ToString("yy-MM-dd hh:mm:ss"))) ;
   }

   private void Radio_OnTransmitSuccess()
   {
      Debug.WriteLine("Radio_OnTransmitSuccess");
   }

   private void Radio_OnTransmitFailed()
   {
      Debug.WriteLine("Radio_OnTransmitFailed");
   }
}

Interrupt Triggered: FallingEdge
Data Sent!
Radio_OnTransmitSuccess
Interrupt Triggered: RisingEdge
Interrupt Triggered: FallingEdge
Received: 20.4 70.7
Interrupt Triggered: RisingEdge
Interrupt Triggered: FallingEdge
Data Sent!
Radio_OnTransmitSuccess
Interrupt Triggered: RisingEdge
Interrupt Triggered: FallingEdge
Received: 20.3 70.8
Interrupt Triggered: RisingEdge

The Raspberry PI could reliably receive and transmit messages.