Getting this bit too work took a bit longer than expected. The code below works but isn’t super efficient. I must be reading the SX1276 SPI timing diagram wrong or I need to read the .NetMF SPI implementation code some more.
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// Copyright (c) August 2018, devMobile Software
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namespace devMobile.NetMF.Rfm9X.RegisterRead
{
using System;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware;
using SecretLabs.NETMF.Hardware.Netduino;
public class Program
{
public static void Main()
{
//OutputPort reset = new OutputPort(Pins.GPIO_PIN_D9, true);
OutputPort chipSelect = null;
//chipSelect = new OutputPort(Pins.GPIO_PIN_D10, true);
//SPI spiPort = new SPI(new SPI.Configuration(Pins.GPIO_NONE, false, 0, 0, true, true, 500, SPI.SPI_module.SPI1));
SPI spiPort = new SPI(new SPI.Configuration(Pins.GPIO_PIN_D10, false, 0, 0, false, true, 500, SPI.SPI_module.SPI1));
Thread.Sleep(100);
while (true)
{
//byte[] writeBuffer = new byte[] { 0x42 }; // RegVersion exptecing 0x12
byte[] writeBuffer = new byte[] { 0x06 }; // RegFreqMsb expecting 0x6C
//byte[] writeBuffer = new byte[] { 0x07 }; // RegFreqMid expecting 0x80
//byte[] writeBuffer = new byte[] { 0x08 }; // RegFreqLsb expecting 0x00
byte[] readBuffer = new byte[1];
if (chipSelect != null)
{
chipSelect.Write(false);
}
spiPort.WriteRead(writeBuffer, readBuffer, 1);
if (chipSelect != null)
{
chipSelect.Write(true);
}
Debug.Print("Value = 0x" + BytesToHexString(readBuffer));
Thread.Sleep(1000);
}
}
private static string BytesToHexString(byte[] bytes)
{
string hexString = string.Empty;
// Create a character array for hexidecimal conversion.
const string hexChars = "0123456789ABCDEF";
// Loop through the bytes.
for (byte b = 0; b 0)
hexString += "-";
// Grab the top 4 bits and append the hex equivalent to the return string.
hexString += hexChars[bytes[b] >> 4];
// Mask off the upper 4 bits to get the rest of it.
hexString += hexChars[bytes[b] & 0x0F];
}
return hexString;
}
}
}
The output indicated that I could success fully read the middle byte (of three) of the transmit frequency and it matched the default. There seems to be something odd about the chip select line/ sequencing
The thread '' (0x2) has exited with code 0 (0x0). Value = 0xE4 Value = 0xE4 Value = 0xE4 Value = 0xE4 Value = 0xE4 Value = 0xE4
It’s late, so the next step will be scanning the SX1276 registers and starting to build out the register manager code to read+write byte values, word values and arrays.
Also noticed that setup seems to work a bit better on a Netduino3 device, have noticed this before with higher power consumption shields.
