Grove – Laser PM2.5 Sensor(HM3301) trial

In preparation for a project to monitor the particulates levels around the 3D Printers and Laser Cutters in a school makerspace I purchased a Grove -Laser PM2.5 Sensor (HM3301) for evaluation.

Seeeduino, Grove HM3301 and easysensors shield

The Seeeduino Nano devices I’m testing have a single on-board I2C socket which meant I didn’t need a Grove Shield for Arduino Nano which reduced the size and cost of the sensor node.

To test my setup I installed the Seeed PM2.5 Sensor HM3301 Software Library and downloaded the demo application to my device.

I started with my Easy Sensors Arduino Nano Radio Shield RFM69/95 Payload Addressing client and modified it to use the HM3301 sensor.

After looking at the demo application I stripped out the checksum code and threw the rest away. In my test harness I have extracted only the PM1.0/PM2.5/PM10.0 (concentration CF=1, Standard particulate) in μg/ m3 values from the sensor response payload.

/*
  Copyright ® 2019 August 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 <stdlib.h&gt;
#include <LoRa.h&gt;
#include <sha204_library.h&gt;
#include "Seeed_HM330X.h"

//#define DEBUG
//#define DEBUG_TELEMETRY
//#define DEBUG_LORA

const byte SensorPayloadLength = 28 ;
const byte SensorPayloadBufferSize  = 29 ;
const byte SensorPayloadPM1_0Position = 4;
const byte SensorPayloadPM2_5Position = 6;
const byte SensorPayloadPM10_0Position = 8;

HM330X sensor;
byte SensorPayload[SensorPayloadBufferSize];
  
// LoRa field gateway configuration (these settings must match your field gateway)
const byte DeviceAddressMaximumLength = 15 ;
const char FieldGatewayAddress[] = {"LoRaIoT1"};
const float FieldGatewayFrequency =  915000000.0;
const byte FieldGatewaySyncWord = 0x12 ;

// Payload configuration
const int ChipSelectPin = 10;
const int ResetPin = 9;
const int InterruptPin = 2;

// LoRa radio payload configuration
const byte SensorIdValueSeperator = ' ' ;
const byte SensorReadingSeperator = ',' ;
const unsigned long SensorUploadDelay = 60000;

// ATSHA204 secure authentication, validation with crypto and hashing (currently only using for unique serial number)
const byte Atsha204Port = A3;
atsha204Class sha204(Atsha204Port);
const byte DeviceSerialNumberLength = 9 ;
byte deviceSerialNumber[DeviceSerialNumberLength] = {""};

const byte PayloadSizeMaximum = 64 ;
byte payload[PayloadSizeMaximum];
byte payloadLength = 0 ;


void setup()
{
  Serial.begin(9600);

#ifdef DEBUG
  while (!Serial);
#endif
 
  Serial.println("Setup called");

  Serial.print("Field gateway:");
  Serial.print(FieldGatewayAddress ) ;
  Serial.print(" Frequency:");
  Serial.print( FieldGatewayFrequency,0 ) ;
  Serial.print("MHz SyncWord:");
  Serial.print( FieldGatewaySyncWord ) ;
  Serial.println();
  
   // Retrieve the serial number then display it nicely
  if(sha204.getSerialNumber(deviceSerialNumber))
  {
    Serial.println("sha204.getSerialNumber failed");
    while (true); // Drop into endless loop requiring restart
  }

  Serial.print("SNo:");
  DisplayHex( deviceSerialNumber, DeviceSerialNumberLength);
  Serial.println();

  Serial.println("LoRa setup start");

  // override the default chip select and reset pins
  LoRa.setPins(ChipSelectPin, ResetPin, InterruptPin);
  if (!LoRa.begin(FieldGatewayFrequency))
  {
    Serial.println("LoRa begin failed");
    while (true); // Drop into endless loop requiring restart
  }

  // Need to do this so field gateway pays attention to messsages from this device
  LoRa.enableCrc();
  LoRa.setSyncWord(FieldGatewaySyncWord);

#ifdef DEBUG_LORA
  LoRa.dumpRegisters(Serial);
#endif
  Serial.println("LoRa Setup done.");

  // Configure the Seeedstudio CO2, temperature &amp; humidity sensor
  Serial.println("HM3301 setup start");
  if(sensor.init())
  {
    Serial.println("HM3301 init failed");
    while (true); // Drop into endless loop requiring restart
  
  }
  delay(100);
  Serial.println("HM3301 setup done");

  PayloadHeader((byte *)FieldGatewayAddress,strlen(FieldGatewayAddress), deviceSerialNumber, DeviceSerialNumberLength);

  Serial.println("Setup done");
  Serial.println();
}

void loop()
{
  unsigned long currentMilliseconds = millis();  
  byte sum=0;
  short pm1_0 ;
  short pm2_5 ;
  short pm10_0 ;

  Serial.println("Loop called");

  if(sensor.read_sensor_value(SensorPayload,SensorPayloadBufferSize) == NO_ERROR)
  {
    // Calculate then validate the payload "checksum"
    for(int i=0;i<SensorPayloadLength;i++)
    {
        sum+=SensorPayload[i];
    }
    if(sum!=SensorPayload[SensorPayloadLength])
    {
        Serial.println("Invalid checksum");
        return;
    }    

    PayloadReset();
    
    pm1_0 = (u16)SensorPayload[SensorPayloadPM1_0Position]<<8|SensorPayload[SensorPayloadPM1_0Position+1];
    Serial.print("PM1.5: ");
    Serial.print(pm1_0);
    Serial.println("ug/m3 ") ;

    PayloadAdd( "P10", pm1_0, false);
    
    pm2_5 = (u16)SensorPayload[SensorPayloadPM2_5Position]<<8|SensorPayload[SensorPayloadPM2_5Position+1];
    Serial.print("PM2.5: ");
    Serial.print(pm2_5);
    Serial.println("ug/m3 ") ;

    PayloadAdd( "P25", pm2_5, 1, false);

    pm10_0 = (u16)SensorPayload[SensorPayloadPM10_0Position]<<8|SensorPayload[SensorPayloadPM10_0Position+1];
    Serial.print("PM10.0: ");
    Serial.print(pm10_0);
    Serial.println("ug/m3 ");

    PayloadAdd( "P100", pm10_0, 0, true) ;

    #ifdef DEBUG_TELEMETRY
      Serial.println();
      Serial.print("RFM9X/SX127X Payload length:");
      Serial.print(payloadLength);
      Serial.println(" bytes");
    #endif

    LoRa.beginPacket();
    LoRa.write(payload, payloadLength);
    LoRa.endPacket();
  }
  Serial.println("Loop done");
  Serial.println();
  
  delay(SensorUploadDelay - (millis() - currentMilliseconds ));
}

void PayloadHeader( const byte *to, byte toAddressLength, const byte *from, byte fromAddressLength)
{
  byte addressesLength = toAddressLength + fromAddressLength ;

  payloadLength = 0 ;

  // prepare the payload header with "To" Address length (top nibble) and "From" address length (bottom nibble)
  
  payload[payloadLength] = (toAddressLength << 4) | fromAddressLength ;
  payloadLength += 1;

  // Copy the "To" address into payload
  memcpy(&amp;payload[payloadLength], to, toAddressLength);
  payloadLength += toAddressLength ;

  // Copy the "From" into payload
  memcpy(&amp;payload[payloadLength], from, fromAddressLength);
  payloadLength += fromAddressLength ;
}

void PayloadAdd( const char *sensorId, float value, byte decimalPlaces, bool last)
{
  byte sensorIdLength = strlen( sensorId ) ;

  memcpy( &amp;payload[payloadLength], sensorId,  sensorIdLength) ;
  payloadLength += sensorIdLength ;
  payload[ payloadLength] = SensorIdValueSeperator;
  payloadLength += 1 ;
  payloadLength += strlen( dtostrf(value, -1, decimalPlaces, (char *)&amp;payload[payloadLength]));
  if (!last)
  {
    payload[ payloadLength] = SensorReadingSeperator;
    payloadLength += 1 ;
  }
  
#ifdef DEBUG_TELEMETRY
  Serial.print("PayloadAdd float-payloadLength:");
  Serial.print( payloadLength);
  Serial.println( );
#endif
}

void PayloadAdd( char *sensorId, int value, bool last )
{
  byte sensorIdLength = strlen(sensorId) ;

  memcpy(&amp;payload[payloadLength], sensorId,  sensorIdLength) ;
  payloadLength += sensorIdLength ;
  payload[ payloadLength] = SensorIdValueSeperator;
  payloadLength += 1 ;
  payloadLength += strlen(itoa( value,(char *)&amp;payload[payloadLength],10));
  if (!last)
  {
    payload[ payloadLength] = SensorReadingSeperator;
    payloadLength += 1 ;
  }
  
#ifdef DEBUG_TELEMETRY
  Serial.print("PayloadAdd int-payloadLength:" );
  Serial.print(payloadLength);
  Serial.println( );
#endif
}

void PayloadAdd( char *sensorId, unsigned int value, bool last )
{
  byte sensorIdLength = strlen(sensorId) ;

  memcpy(&amp;payload[payloadLength], sensorId,  sensorIdLength) ;
  payloadLength += sensorIdLength ;
  payload[ payloadLength] = SensorIdValueSeperator;
  payloadLength += 1 ;
  payloadLength += strlen(utoa( value,(char *)&amp;payload[payloadLength],10));
  if (!last)
  {
    payload[ payloadLength] = SensorReadingSeperator;
    payloadLength += 1 ;
  }
  
#ifdef DEBUG_TELEMETRY
  Serial.print("PayloadAdd uint-payloadLength:");
  Serial.print(payloadLength);
  Serial.println( );
#endif
}

void PayloadReset()
{
  byte fromAddressLength = payload[0] &amp; 0xf ;
  byte toAddressLength = payload[0] &gt;&gt; 4 ;
  
  payloadLength = toAddressLength + fromAddressLength + 1;
}

void DisplayHex( byte *byteArray, byte length) 
{
  for (int i = 0; i < length ; i++)
  {
    // Add a leading zero
    if ( byteArray[i] < 16)
    {
      Serial.print("0");
    }
    Serial.print(byteArray[i], HEX);
    if ( i < (length-1)) // Don't put a - after last digit
    {
      Serial.print("-");
    }
  }
}    

The code is available on GitHub.

20:45:38.021 -> Setup called
20:45:38.054 -> Field gateway:LoRaIoT1 Frequency:915000000MHz SyncWord:18
20:45:38.156 -> SNo:01-23-8C-48-D6-D1-F5-86-EE
20:45:38.190 -> LoRa setup start
20:45:38.190 -> LoRa Setup done.
20:45:38.224 -> HM3301 setup start
20:45:38.292 -> HM3301 setup done
20:45:38.292 -> Setup done
20:45:38.292 -> 
20:45:38.325 -> Loop called
20:45:38.325 -> PM1.5: 10ug/m3 
20:45:38.359 -> PM2.5: 14ug/m3 
20:45:38.359 -> PM10.0: 19ug/m3 
20:45:38.393 -> Loop done
20:45:38.393 -> 
20:46:38.220 -> Loop called
20:46:38.220 -> PM1.5: 10ug/m3 
20:46:38.255 -> PM2.5: 15ug/m3 
20:46:38.255 -> PM10.0: 20ug/m3 
20:46:38.325 -> Loop done
20:46:38.325 -> 
20:47:38.181 -> Loop called
20:47:38.181 -> PM1.5: 10ug/m3 
20:47:38.181 -> PM2.5: 14ug/m3 
20:47:38.216 -> PM10.0: 19ug/m3 
20:47:38.250 -> Loop done
20:47:38.284 -> 
20:48:38.123 -> Loop called
20:48:38.123 -> PM1.5: 10ug/m3 
20:48:38.158 -> PM2.5: 14ug/m3 
20:48:38.158 -> PM10.0: 19ug/m3 
20:48:38.193 -> Loop done
20:48:38.227 -> 
20:49:38.048 -> Loop called
20:49:38.082 -> PM1.5: 10ug/m3 
20:49:38.082 -> PM2.5: 14ug/m3 
20:49:38.117 -> PM10.0: 19ug/m3 
20:49:38.151 -> Loop done
20:49:38.151 -> 
20:50:38.010 -> Loop called
20:50:38.010 -> PM1.5: 9ug/m3 
20:50:38.010 -> PM2.5: 13ug/m3 
20:50:38.045 -> PM10.0: 18ug/m3 
20:50:38.079 -> Loop done
20:50:38.079 -> 

To configure the device in Azure IoT Central (similar process for Adafruit.IO, working on support for losant, ubidots and MyDevices) I copied the SNo: from the Arduino development tool logging window and appended p10 for PM 1 value, p25 for PM2.5 value and p100 for PM10 value to the unique serial number from the ATSHA204A chip. (N.B. pay attention to the case of the field names they are case sensitive)

Azure IoT Central telemetry configuration

The rapidly settled into a narrow range of readings, but spiked when I took left it outside (winter in New Zealand) and the values spiked when food was being cooked in the kitchen which is next door to my office.

It would be good to run the sensor alongside a professional particulates monitor so the values could be compared and used to adjust the readings of the Grove sensor if necessary.

Hour of PM1, PM2.5 & PM10 readings in my office early evening
CO2 and particulates values while outside on my deck from 10:30pm to 11:30pm

Bill of materials (prices as at August 2019)

  • Seeeduino Nano USD6.90
  • Grove – Laser PM2.5 Sensor (HM3301) USD29.90
  • EasySensors Arduino Nano radio shield RFM95 USD15.00

Grove – Carbon Dioxide Sensor(SCD30) trial

In preparation for another student project to monitor the temperature, humidity and CO2 levels in a number of classrooms I purchased a couple of Grove – CO2, Temperature & Humidity Sensors (SCD30) for evaluation.

Seeeduino, Grove SCD30 and easysensors shield

Seeeduino Nano devices have a single on-board I2C socket which meant I didn’t need a Grove Shield for Arduino Nano which reduced the size and cost of the sensor node.

I downloaded the seeedstudio wiki example calibration code, compiled and uploaded it to one of my Seeeduino Nano devices. When activated for the first time a period of minimum 7 days is needed so that the sensor algorithm can find its initial parameter set. During this period the sensor has to be exposed to fresh air for at least 1 hour every day.

During the calibration process I put the device in my garage and left the big door open for at least an hour every day. Once the sensor was calibrated I bought it inside at put it on the bookcase in my office.

I modified my Easy Sensors Arduino Nano Radio Shield RFM69/95 Payload Addressing client to use the sensor.

/*
  Copyright ® 2019 August 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 <stdlib.h&gt;
#include <LoRa.h&gt;
#include <sha204_library.h&gt;
#include "SCD30.h"

//#define DEBUG
//#define DEBUG_TELEMETRY
//#define DEBUG_LORA

// LoRa field gateway configuration (these settings must match your field gateway)
const byte DeviceAddressMaximumLength = 15 ;
const char FieldGatewayAddress[] = {"LoRaIoT1"};
const float FieldGatewayFrequency =  915000000.0;
const byte FieldGatewaySyncWord = 0x12 ;

// Payload configuration
const int ChipSelectPin = 10;
const int ResetPin = 9;
const int InterruptPin = 2;

// LoRa radio payload configuration
const byte SensorIdValueSeperator = ' ' ;
const byte SensorReadingSeperator = ',' ;
const unsigned long SensorUploadDelay = 300000;

// ATSHA204 secure authentication, validation with crypto and hashing (currently only using for unique serial number)
const byte Atsha204Port = A3;
atsha204Class sha204(Atsha204Port);
const byte DeviceSerialNumberLength = 9 ;
byte deviceSerialNumber[DeviceSerialNumberLength] = {""};

const byte PayloadSizeMaximum = 64 ;
byte payload[PayloadSizeMaximum];
byte payloadLength = 0 ;


void setup()
{
  Serial.begin(9600);

#ifdef DEBUG
  while (!Serial);
#endif
 
  Serial.println("Setup called");

  Serial.print("Field gateway:");
  Serial.print(FieldGatewayAddress ) ;
  Serial.print(" Frequency:");
  Serial.print( FieldGatewayFrequency,0 ) ;
  Serial.print("MHz SyncWord:");
  Serial.print( FieldGatewaySyncWord ) ;
  Serial.println();
  
   // Retrieve the serial number then display it nicely
  if(sha204.getSerialNumber(deviceSerialNumber))
  {
    Serial.println("sha204.getSerialNumber failed");
    while (true); // Drop into endless loop requiring restart
  }

  Serial.print("SNo:");
  DisplayHex( deviceSerialNumber, DeviceSerialNumberLength);
  Serial.println();

  Serial.println("LoRa setup start");

  // override the default chip select and reset pins
  LoRa.setPins(ChipSelectPin, ResetPin, InterruptPin);
  if (!LoRa.begin(FieldGatewayFrequency))
  {
    Serial.println("LoRa begin failed");
    while (true); // Drop into endless loop requiring restart
  }

  // Need to do this so field gateway pays attention to messsages from this device
  LoRa.enableCrc();
  LoRa.setSyncWord(FieldGatewaySyncWord);

#ifdef DEBUG_LORA
  LoRa.dumpRegisters(Serial);
#endif
  Serial.println("LoRa Setup done.");

  // Configure the Seeedstudio CO2, temperature &amp; humidity sensor
  Serial.println("SCD30 setup start");
  Wire.begin();
  scd30.initialize();  
  delay(100);
  Serial.println("SCD30 setup done");

  PayloadHeader((byte *)FieldGatewayAddress,strlen(FieldGatewayAddress), deviceSerialNumber, DeviceSerialNumberLength);

  Serial.println("Setup done");
  Serial.println();
}

void loop()
{
  unsigned long currentMilliseconds = millis();  
  float temperature ;
  float humidity ;
  float co2;

  Serial.println("Loop called");

  if(scd30.isAvailable())
  {
    float result[3] = {0};
    PayloadReset();

    // Read the CO2, temperature &amp; humidity values then display nicely
    scd30.getCarbonDioxideConcentration(result);

    co2 = result[0];
    Serial.print("C:");
    Serial.print(co2, 1) ;
    Serial.println("ppm ") ;

    PayloadAdd( "C", co2, 1, false);
    
    temperature = result[1];
    Serial.print("T:");
    Serial.print(temperature, 1) ;
    Serial.println("C ") ;

    PayloadAdd( "T", temperature, 1, false);

    humidity = result[2];
    Serial.print("H:" );
    Serial.print(humidity, 0) ;
    Serial.println("% ") ;

    PayloadAdd( "H", humidity, 0, true) ;

    #ifdef DEBUG_TELEMETRY
      Serial.println();
      Serial.print("RFM9X/SX127X Payload length:");
      Serial.print(payloadLength);
      Serial.println(" bytes");
    #endif

    LoRa.beginPacket();
    LoRa.write(payload, payloadLength);
    LoRa.endPacket();
  }
  Serial.println("Loop done");
  Serial.println();
  
  delay(SensorUploadDelay - (millis() - currentMilliseconds ));
}
...
}    

The code is available on GitHub.

20:38:56.746 -> Setup called
20:38:56.746 -> Field gateway: Frequency:915000000MHz SyncWord:18
20:38:56.849 -> SNo:01-23-39-BD-D6-D1-F5-86-EE
20:38:56.884 -> LoRa setup start
20:38:56.919 -> LoRa Setup done.
20:38:56.919 -> SCD30 setup start
20:38:56.986 -> SCD30 setup done
20:38:56.986 -> Setup done
20:38:57.020 -> 
20:39:06.966 -> Received packet
20:39:06.966 -> Packet size:18
20:39:06.999 -> To len:9
20:39:06.999 -> From len:8
20:39:06.999 -> To:01-23-39-BD-D6-D1-F5-86-EE
20:39:07.034 -> From:4C-6F-52-61-49-6F-54-31
20:39:07.069 -> FieldGateway:4C-6F-52-61-49-6F-54-31
20:39:07.104 -> RSSI -55
20:39:07.139 -> Loop called
20:39:07.139 -> C:730.8ppm 
20:39:07.139 -> T:23.1C 
20:39:07.173 -> H:46% 
20:39:07.173 -> Loop done
20:39:07.208 -> 
20:39:37.123 -> Loop called
20:39:37.158 -> C:529.9ppm 
20:39:37.158 -> T:23.2C 
20:39:37.158 -> H:48% 
20:39:37.228 -> Loop done
20:39:37.228 -> 

To configure the device in Azure IoT Central (similar process for Adafruit.IO, working on support for losant, ubidots and MyDevices) I copied the SNo: from the Arduino development tool logging window and appended c for the CO2 parts per million (ppm), h for the humidity % and t for the temperature °C to the unique serial number from the ATSHA204A chip. (N.B. pay attention to the case of the field names they are case sensitive)

Azure IoT Central telemetry configuration

Overall the performance of the sensor is looking pretty positive, the CO2 levels fluctuate in a acceptable range (based on office occupancy), and the temperature + humidity readings track quite closely to the other two sensor nodes in my office. The only issue so far is my lack of USB-C cables to power the devices in the field

CO2, Humidity and Temperature in my office for a day

Bill of materials (prices as at August 2019)

  • Seeeduino Nano USD6.90
  • Grove – CO2, Humidity & Temperature Sensor(SCD30) USD59.95
  • EasySensors Arduino Nano radio shield RFM95 USD15.00

STM32 Blue Pill LoRaWAN node

A few weeks ago I ordered an STM32 Blue Pill LoRaWAN node from the M2M Shop on Tindie for evaluation. I have bought a few M2M client devices including a Low power LoRaWan Node Model A328, and Low power LoRaWan Node Model B1284 for projects and they have worked well. This one looked interesting as I had never used a maple like device before.

Bill of materials (Prices as at July 2019)

  • STM32 Blue Pill LoRaWAN node USD21
  • Grove – Temperature&Humidity Sensor USD11.5
  • Grove – 4 pin Female Jumper to Grove 4 pin Conversion Cable USD3.90

The two sockets on the main board aren’t Grove compatible so I used the 4 pin female to Grove 4 pin conversion cable to connect the temperature and humidity sensor.

STM32 Blue Pill LoRaWAN node test rig

I used a modified version of my Arduino client code which worked after I got the pin reset pin sorted and the female sockets in the right order.

/*
  Copyright ® 2019 July 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.
  
  Adapted from LoRa Duplex communication with Sync Word

  Sends temperature &amp; humidity data from Seeedstudio 

  https://www.seeedstudio.com/Grove-Temperature-Humidity-Sensor-High-Accuracy-Min-p-1921.html

  To my Windows 10 IoT Core RFM 9X library

  https://blog.devmobile.co.nz/2018/09/03/rfm9x-iotcore-payload-addressing/
*/
#include <itoa.h&gt;     
#include <SPI.h&gt;     
#include <LoRa.h&gt;

#include <TH02_dev.h&gt;

#define DEBUG
//#define DEBUG_TELEMETRY
//#define DEBUG_LORA

// LoRa field gateway configuration (these settings must match your field gateway)
const char DeviceAddress[] = {"BLUEPILL"};

// Azure IoT Hub FieldGateway
const char FieldGatewayAddress[] = {"LoRaIoT1"}; 
const float FieldGatewayFrequency =  915000000.0;
const byte FieldGatewaySyncWord = 0x12 ;

// Bluepill hardware configuration
const int ChipSelectPin = PA4;
const int InterruptPin = PA0;
const int ResetPin = -1;

// LoRa radio payload configuration
const byte SensorIdValueSeperator = ' ' ;
const byte SensorReadingSeperator = ',' ;
const byte PayloadSizeMaximum = 64 ;
byte payload[PayloadSizeMaximum];
byte payloadLength = 0 ;

const int LoopDelaySeconds = 300 ;

// Sensor configuration
const char SensorIdTemperature[] = {"t"};
const char SensorIdHumidity[] = {"h"};


void setup()
{
  Serial.begin(9600);
#ifdef DEBUG
  while (!Serial);
#endif
  Serial.println("Setup called");

  Serial.println("LoRa setup start");

  // override the default chip select and reset pins
  LoRa.setPins(ChipSelectPin, ResetPin, InterruptPin);
  if (!LoRa.begin(FieldGatewayFrequency))
  {
    Serial.println("LoRa begin failed");
    while (true); // Drop into endless loop requiring restart
  }

  // Need to do this so field gateways pays attention to messsages from this device
  LoRa.enableCrc();
  LoRa.setSyncWord(FieldGatewaySyncWord);

#ifdef DEBUG_LORA
  LoRa.dumpRegisters(Serial);
#endif
  Serial.println("LoRa setup done.");

  PayloadHeader((byte*)FieldGatewayAddress, strlen(FieldGatewayAddress), (byte*)DeviceAddress, strlen(DeviceAddress));

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

  Serial.println("Setup done");
}

void loop() {
  // read the value from the sensor:
  double temperature = TH02.ReadTemperature();
  double humidity = TH02.ReadHumidity();

  Serial.print("Humidity: ");
  Serial.print(humidity, 0);
  Serial.print(" %\t");
  Serial.print("Temperature: ");
  Serial.print(temperature, 1);
  Serial.println(" *C");

  PayloadReset();

  PayloadAdd(SensorIdHumidity, humidity, 0) ;
  PayloadAdd(SensorIdTemperature, temperature, 1) ;

  LoRa.beginPacket();
  LoRa.write(payload, payloadLength);
  LoRa.endPacket();

  Serial.println("Loop done");

  delay(LoopDelaySeconds * 1000);
}


void PayloadHeader( byte *to, byte toAddressLength, byte *from, byte fromAddressLength)
{
  byte addressesLength = toAddressLength + fromAddressLength ;

#ifdef DEBUG_TELEMETRY
  Serial.println("PayloadHeader- ");
  Serial.print( "To Address len:");
  Serial.print( toAddressLength );
  Serial.print( " From Address len:");
  Serial.print( fromAddressLength );
  Serial.print( " Addresses length:");
  Serial.print( addressesLength );
  Serial.println( );
#endif

  payloadLength = 0 ;

  // prepare the payload header with "To" Address length (top nibble) and "From" address length (bottom nibble)
  payload[payloadLength] = (toAddressLength << 4) | fromAddressLength ;
  payloadLength += 1;

  // Copy the "To" address into payload
  memcpy(&amp;payload[payloadLength], to, toAddressLength);
  payloadLength += toAddressLength ;

  // Copy the "From" into payload
  memcpy(&amp;payload[payloadLength], from, fromAddressLength);
  payloadLength += fromAddressLength ;
}


void PayloadAdd( const char *sensorId, float value, byte decimalPlaces)
{
  byte sensorIdLength = strlen( sensorId ) ;

#ifdef DEBUG_TELEMETRY
  Serial.println("PayloadAdd-float ");
  Serial.print( "SensorId:");
  Serial.print( sensorId );
  Serial.print( " sensorIdLen:");
  Serial.print( sensorIdLength );
  Serial.print( " Value:");
  Serial.print( value, decimalPlaces );
  Serial.print( " payloadLength:");
  Serial.print( payloadLength);
#endif

  memcpy( &amp;payload[payloadLength], sensorId,  sensorIdLength) ;
  payloadLength += sensorIdLength ;
  payload[ payloadLength] = SensorIdValueSeperator;
  payloadLength += 1 ;
  payloadLength += strlen( dtostrf(value, -1, decimalPlaces, (char *)&amp;payload[payloadLength]));
  payload[ payloadLength] = SensorReadingSeperator;
  payloadLength += 1 ;

#ifdef DEBUG_TELEMETRY
  Serial.print( " payloadLength:");
  Serial.print( payloadLength);
  Serial.println( );
#endif
}


void PayloadAdd( const char *sensorId, int value )
{
  byte sensorIdLength = strlen( sensorId ) ;

#ifdef DEBUG_TELEMETRY
  Serial.println("PayloadAdd-int ");
  Serial.print( "SensorId:");
  Serial.print( sensorId );
  Serial.print( " sensorIdLen:");
  Serial.print( sensorIdLength );
  Serial.print( " Value:");
  Serial.print( value );
  Serial.print( " payloadLength:");
  Serial.print( payloadLength);
#endif

  memcpy( &amp;payload[payloadLength], sensorId,  sensorIdLength) ;
  payloadLength += sensorIdLength ;
  payload[ payloadLength] = SensorIdValueSeperator;
  payloadLength += 1 ;
  payloadLength += strlen( itoa( value, (char *)&amp;payload[payloadLength], 10));
  payload[ payloadLength] = SensorReadingSeperator;
  payloadLength += 1 ;

#ifdef DEBUG_TELEMETRY
  Serial.print( " payloadLength:");
  Serial.print( payloadLength);
  Serial.println( );
#endif
}

void PayloadAdd( const char *sensorId, unsigned int value )
{
  byte sensorIdLength = strlen( sensorId ) ;

#ifdef DEBUG_TELEMETRY
  Serial.println("PayloadAdd-unsigned int ");
  Serial.print( "SensorId:");
  Serial.print( sensorId );
  Serial.print( " sensorIdLen:");
  Serial.print( sensorIdLength );
  Serial.print( " Value:");
  Serial.print( value );
  Serial.print( " payloadLength:");
  Serial.print( payloadLength);
#endif

  memcpy( &amp;payload[payloadLength], sensorId,  sensorIdLength) ;
  payloadLength += sensorIdLength ;
  payload[ payloadLength] = SensorIdValueSeperator;
  payloadLength += 1 ;
  payloadLength += strlen( utoa( value, (char *)&amp;payload[payloadLength], 10));
  payload[ payloadLength] = SensorReadingSeperator;
  payloadLength += 1 ;

#ifdef DEBUG_TELEMETRY
  Serial.print( " payloadLength:");
  Serial.print( payloadLength);
  Serial.println( );
#endif
}


void PayloadReset()
{
  byte fromAddressLength = payload[0] &amp; 0xf ;
  byte toAddressLength = payload[0] &gt;&gt; 4 ;
  byte addressesLength = toAddressLength + fromAddressLength ;

  payloadLength = addressesLength + 1;

#ifdef DEBUG_TELEMETRY
  Serial.println("PayloadReset- ");
  Serial.print( "To Address len:");
  Serial.print( toAddressLength );
  Serial.print( " From Address len:");
  Serial.print( fromAddressLength );
  Serial.print( " Addresses length:");
  Serial.print( addressesLength );
  Serial.println( );
#endif
}

To get the application to compile I also had to include itoa.h rather than stdlib.h.

maple_loader v0.1
Resetting to bootloader via DTR pulse
[Reset via USB Serial Failed! Did you select the right serial port?]
Searching for DFU device [1EAF:0003]...
Assuming the board is in perpetual bootloader mode and continuing to attempt dfu programming...

dfu-util - (C) 2007-2008 by OpenMoko Inc.

Initially I had some problems deploying my software because I hadn’t followed the instructions and run the installation batch file.

14:03:56.946 -> Setup called
14:03:56.946 -> LoRa setup start
14:03:56.946 -> LoRa setup done.
14:03:56.946 -> TH02 setup
14:03:57.046 -> TH02 Setup done
14:03:57.046 -> Setup done
14:03:57.115 -> Humidity: 76 %	Temperature: 18.9 *C
14:03:57.182 -> Loop done
14:08:57.226 -> Humidity: 74 %	Temperature: 18.7 *C
14:08:57.295 -> Loop done
14:13:57.360 -> Humidity: 76 %	Temperature: 18.3 *C
14:13:57.430 -> Loop done
14:18:57.475 -> Humidity: 74 %	Temperature: 18.2 *C
14:18:57.544 -> Loop done
14:23:57.593 -> Humidity: 70 %	Temperature: 17.8 *C
14:23:57.662 -> Loop done
14:28:57.733 -> Humidity: 71 %	Temperature: 17.8 *C
14:28:57.802 -> Loop done
14:33:57.883 -> Humidity: 73 %	Temperature: 17.9 *C
14:33:57.952 -> Loop done
14:38:57.997 -> Humidity: 73 %	Temperature: 18.0 *C
14:38:58.066 -> Loop done
14:43:58.138 -> Humidity: 73 %	Temperature: 18.1 *C
14:43:58.208 -> Loop done
14:48:58.262 -> Humidity: 73 %	Temperature: 18.3 *C
14:48:58.331 -> Loop done
14:53:58.374 -> Humidity: 73 %	Temperature: 18.2 *C
14:53:58.444 -> Loop done
14:58:58.509 -> Humidity: 73 %	Temperature: 18.3 *C
14:58:58.578 -> Loop done
15:03:58.624 -> Humidity: 65 %	Temperature: 16.5 *C
15:03:58.694 -> Loop done
15:08:58.766 -> Humidity: 71 %	Temperature: 18.8 *C
15:08:58.836 -> Loop done
15:13:58.893 -> Humidity: 75 %	Temperature: 19.1 *C
15:13:58.963 -> Loop done

I configured the device to upload to my Azure IoT Hub/Azure IoT Central gateway and after getting the device name configuration right it has been running reliably for a couple of days

Azure IoT Central Temperature and humidity

The device was sitting outside on the deck and rapid increase in temperature is me bringing it inside.

Low power LoRaWan Node Model B1248 Payload Addressing Client

This is a demo M2M Low power LoRaWan Node Model B1284 client (based on one of the examples from Arduino-LoRa) that uploads telemetry data to my Windows 10 IoT Core on Raspberry PI AdaFruit.IO and Azure IoT Hub field gateways.

LoraWanNodeV1_0_0

The compiler used by the Arduino tooling for this processor was stricter about byte-char conversions so a couple of extra casts were necessary.

/*
  Adapted from LoRa Duplex communication with Sync Word

  Sends temperature & humidity data from Seeedstudio 

  https://www.seeedstudio.com/Grove-Temperature-Humidity-Sensor-High-Accuracy-Min-p-1921.html

  To my Windows 10 IoT Core RFM 9X library

  https://blog.devmobile.co.nz/2018/09/03/rfm9x-iotcore-payload-addressing/

*/
#include               // include libraries
#include
#include
const int csPin = 14;          // LoRa radio chip select
const int resetPin = 9;       // LoRa radio reset
const int irqPin = 2;         // change for your board; must be a hardware interrupt pin

// Field gateway configuration
const char FieldGatewayAddress[] = "LoRaIoT1";
const float FieldGatewayFrequency =  915000000.0;
const byte FieldGatewaySyncWord = 0x12 ;

// Payload configuration
const int PayloadSizeMaximum = 64 ;
byte payload[PayloadSizeMaximum] = "";
const byte SensorReadingSeperator = ',' ;

// Manual serial number configuration
const char DeviceId[] = {"M2MNodeV100"};

const int LoopSleepDelaySeconds = 10 ;

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

  Serial.println("LoRa Setup");

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

  if (!LoRa.begin(FieldGatewayFrequency))
  {
    Serial.println("LoRa init failed. Check your connections.");
    while (true);
  }

  // Need to do this so field gateway pays attention to messsages from this device
  LoRa.enableCrc();
  LoRa.setSyncWord(FieldGatewaySyncWord);  

  //LoRa.dumpRegisters(Serial);
  Serial.println("LoRa Setup done.");

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

  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 "To" Address length (top nibble) and "From" address length (bottom nibble)
  payload[0] = (strlen(FieldGatewayAddress)<< 4) | strlen( DeviceId ) ;
  payloadLength += 1;

  // Copy the "To" address into payload
  memcpy(&payload[payloadLength], FieldGatewayAddress, strlen(FieldGatewayAddress));
  payloadLength += strlen(FieldGatewayAddress) ;

  // Copy the "From" into payload
  memcpy(&payload[payloadLength], DeviceId, strlen(DeviceId));
  payloadLength += strlen(DeviceId) ;

  // Read the temperature and humidity values then display nicely
  temperature = TH02.ReadTemperature();
  humidity = TH02.ReadHumidity();

  Serial.print("T:");
  Serial.print( temperature, 1 ) ;
  Serial.print( "C" ) ;

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

  // Copy the temperature into the payload
  payload[ payloadLength] = 't';
  payloadLength += 1 ;
  payload[ payloadLength] = ' ';
  payloadLength += 1 ;
  payloadLength += strlen( dtostrf(temperature, -1, 1, (char*)&payload[payloadLength]));
  payload[ payloadLength] = SensorReadingSeperator;
  payloadLength += sizeof(SensorReadingSeperator) ;

  // Copy the humidity into the payload
  payload[ payloadLength] = 'h';
  payloadLength += 1 ;
  payload[ payloadLength] = ' ';
  payloadLength += 1 ;
  payloadLength += strlen( dtostrf(humidity, -1, 0, (char *)&payload[payloadLength]));  

  // display info about payload then send it (No ACK) with LoRa unlike nRF24L01
  Serial.print( "RFM9X/SX127X Payload length:");
  Serial.print( payloadLength );
  Serial.println( " bytes" );

  LoRa.beginPacket();
  LoRa.write( payload, payloadLength );
  LoRa.endPacket();      

  Serial.println("Loop done");

  delay(LoopSleepDelaySeconds * 1000l);
}

Bill of materials (Prices Sep 2018)

  • M2M Low power LoRaWan Node Model B1284 USD40
  • Seeedstudio Temperature&Humidity Sensor USD11.50
  • 4 pin Female Jumper to Grove 4 pin Conversion Cable USD2.90

The code is pretty basic (like the other samples), it shows how to pack the payload and set the necessary RFM9X/SX127X LoRa module configuration, has no power conservation, advanced wireless configuration etc.

The Grove 4 pin Female Jumper to Grove 4 pin Conversion Cable was a quick & convenient way to get the I2C Grove temperature and humidity sensor connected up.

Then in my Azure IoT Hub monitoring software

M2MNodeV100EventHub

Low power LoRaWan Node Model A328 Payload Addressing Client

This is a demo M2M Low power LoRaWan Node Model A328 client (based on one of the examples from Arduino-LoRa) that uploads telemetry data to my Windows 10 IoT Core on Raspberry PI AdaFruit.IO and Azure IoT Hub field gateways.

M2MNodeV351

/*
  Adapted from LoRa Duplex communication with Sync Word

  Sends temperature & humidity data from Seeedstudio 

  https://www.seeedstudio.com/Grove-Temperature-Humidity-Sensor-High-Accuracy-Min-p-1921.html

  To my Windows 10 IoT Core RFM 9X library

  https://blog.devmobile.co.nz/2018/09/03/rfm9x-iotcore-payload-addressing/

*/
#include               // include libraries
#include
#include 

const int csPin = 10;          // LoRa radio chip select
const int resetPin = 9;       // LoRa radio reset
const int irqPin = 2;         // change for your board; must be a hardware interrupt pin

// Field gateway configuration
const char FieldGatewayAddress[] = "LoRaIoT1";
const float FieldGatewayFrequency =  915000000.0;
const byte FieldGatewaySyncWord = 0x12 ;

// Payload configuration
const int PayloadSizeMaximum = 64 ;
byte payload[PayloadSizeMaximum] = "";
const byte SensorReadingSeperator = ',' ;

// Manual serial number configuration
const char DeviceId[] = {"M2MNodeV351"};

const int LoopSleepDelaySeconds = 10 ;

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

  Serial.println("LoRa Setup");

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

  if (!LoRa.begin(FieldGatewayFrequency))
  {
    Serial.println("LoRa init failed. Check your connections.");
    while (true);
  }

  // Need to do this so field gateways pays attention to messages from this device
  LoRa.enableCrc();
  LoRa.setSyncWord(FieldGatewaySyncWord);  

  //LoRa.dumpRegisters(Serial);
  Serial.println("LoRa Setup done.");

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

  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 "To" Address length (top nibble) and "From" address length (bottom nibble)
 payload[0] = (strlen(FieldGatewayAddress) << 4) | strlen( DeviceId ) ;   payloadLength += 1;

  // Copy the "To" address into payload
  memcpy(&payload[payloadLength], FieldGatewayAddress, strlen(FieldGatewayAddress));
  payloadLength += strlen(FieldGatewayAddress) ;

  // Copy the "From" into payload
  memcpy(&payload[payloadLength], DeviceId, strlen(DeviceId));
  payloadLength += strlen(DeviceId) ;

  // Read the temperature and humidity values then display nicely
  temperature = TH02.ReadTemperature();
  humidity = TH02.ReadHumidity();

  Serial.print("T:");
  Serial.print( temperature, 1 ) ;
  Serial.print( "C" ) ;

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

  // Copy the temperature into the payload
  payload[ payloadLength] = 't';
  payloadLength += 1 ;
  payload[ payloadLength] = ' ';
  payloadLength += 1 ;
  payloadLength += strlen( dtostrf(temperature, -1, 1, &payload[payloadLength]));
  payload[ payloadLength] = SensorReadingSeperator;
  payloadLength += sizeof(SensorReadingSeperator) ;

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

  // display info about payload then send it (No ACK) with LoRa unlike nRF24L01
  Serial.print( "RFM9X/SX127X Payload length:");
  Serial.print( payloadLength );
  Serial.println( " bytes" );

  LoRa.beginPacket();
  LoRa.write( payload, payloadLength );
  LoRa.endPacket();      

  Serial.println("Loop done");

  delay(LoopSleepDelaySeconds * 1000l);
}

Bill of materials (Prices Sep 2018)

  • M2M Low power LoRaWan Node Model A328 USD30
  • Seeedstudio Temperature & Humidity Sensor USD11.50
  • 4 pin Female Jumper to Grove 4 pin Conversion Cable USD2.90

The code is pretty basic, it shows how to pack the payload and set the necessary RFM9X/SX127X LoRa module configuration, has no power conservation, advanced wireless configuration etc.

The Grove 4 pin Female Jumper to Grove 4 pin Conversion Cable was a quick & convenient way to get the I2C Grove temperature and humidity sensor connected up.

Then in my Azure IoT Hub monitoring software

M2MNodeV35EventHub

M2M LoRaWan Gateway Shield for Raspberry Pi

This morning a 1 Channel LoRaWan Gateway Shield for Raspberry Pi arrived from M2M along with a Low power LoRaWan Node Model A328 and Low power oRaWan Node Model B1284.

First setup to get the LoRaWan Gateway Shield up and running on my Raspberry PI 3.

M2MLoRaShield

No schematics were available so I had to reverse engineer the configuration for the Single Channel LoRaWAN Gateway for my Windows 10 IoT Core setup.

pins configuration in global_conf.json

“pin_nss”: 6,

“pin_dio0”: 7,

“pin_rst”: 0

If you use RPI0, edit single_chan_pkt_fwd.cpp and change eth0 to wlan0.

First step was to confirm I had the chip select line and SPI configuration sorted by reading the RegVersion register.

//---------------------------------------------------------------------------------
// Copyright (c) August 2018, devMobile Software
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
//---------------------------------------------------------------------------------
namespace devMobile.IoT.Rfm9x.M2MSPI
{
	using System;
	using System.Diagnostics;
	using System.Threading;
	using Windows.ApplicationModel.Background;
	using Windows.Devices.Gpio;
	using Windows.Devices.Spi;

	public sealed class StartupTask : IBackgroundTask
	{
		public void Run(IBackgroundTaskInstance taskInstance)
		{
			GpioPin ChipSelectGpioPin = null;
			const int chipSelectPinNumber = 25;

			SpiController spiController = SpiController.GetDefaultAsync().AsTask().GetAwaiter().GetResult();
			var settings = new SpiConnectionSettings(1)
			{
				ClockFrequency = 500000,
				Mode = SpiMode.Mode0,   // From SemTech docs pg 80 CPOL=0, CPHA=0
			};

			// Chip select pin configuration
			GpioController gpioController = GpioController.GetDefault();
		   ChipSelectGpioPin = gpioController.OpenPin(chipSelectPinNumber);
			ChipSelectGpioPin.SetDriveMode(GpioPinDriveMode.Output);
			ChipSelectGpioPin.Write(GpioPinValue.High);

			SpiDevice Device = spiController.GetDevice(settings);

			while (true)
			{
				byte[] writeBuffer = new byte[] { 0x42 }; // RegVersion
				byte[] readBuffer = new byte[1];

				// Read the RegVersion silicon ID to check SPI works
				ChipSelectGpioPin.Write(GpioPinValue.Low);
				Device.TransferSequential(writeBuffer, readBuffer);
				ChipSelectGpioPin.Write(GpioPinValue.High);
				Debug.WriteLine("Register RegVer 0x{0:x2} - Value 0X{1:x2} - Bits {2}", writeBuffer[0], readBuffer[0], Convert.ToString(readBuffer[0], 2).PadLeft(8, '0'));

				Thread.Sleep(10000);
			}
		}
	}
}

The output confirmed I could read the register

‘backgroundTaskHost.exe’ (CoreCLR: CoreCLR_UWP_Domain): Loaded ‘C:\Data\Users\DefaultAccount\AppData\Local\DevelopmentFiles\M2MSPI-uwpVS.Debug_ARM.Bryn.Lewis\System.Threading.Thread.dll’. Skipped loading symbols. Module is optimized and the debugger option ‘Just My Code’ is enabled.
Register RegVer 0x42 – Value 0X12 – Bits 00010010
Register RegVer 0x42 – Value 0X12 – Bits 00010010

So far the M2M shield looks like a well priced option for my DIY LoRa Gateway deployments.

It arrived promptly and the vendor followed up with sample Arduino code a couple of days after the package shipped.

 

Electronic Tricks Lora/LoraWan shield for Raspberry Pi Zero and PI3

For the example code so far I had been using the Dragino LoRa GPS HAT for Raspberry PI which, after looking at the schematic (to figure out how the chip select line was connected) worked pretty well.

I had also purchased a Lora/LoRaWAN shield for Raspberry PI Zero and PI3 from Tindie (plus some unpopulated printed circuit boards so I can try building a RFM69HCW based shield).

The board didn’t fit on my Raspberry PI 2 & 3 devices so I used a Dexter industries Grove PI0 Shield as a temporary spacer to lift the antenna connector above the USB sockets.

The RFM95 chip select line is connected to pin 24 (GPIO8), the reset line to pin 29(GPIO5) and the interrupt line (RFM95 DIO0) to pin 22(GPIO25).

ElectronicTricksRFM95

My board doesn’t have any Light Emitting Diodes (LEDs) so it was straight into reading register values

//---------------------------------------------------------------------------------
// Copyright (c) July 2018, devMobile Software
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
//---------------------------------------------------------------------------------
namespace devMobile.IoT.Rfm9x.ElectronicTricksSPI
{
	using System;
	using System.Diagnostics;
	using System.Threading;
	using Windows.ApplicationModel.Background;
	using Windows.Devices.Spi;

	public sealed class StartupTask : IBackgroundTask
	{
		public void Run(IBackgroundTaskInstance taskInstance)
		{
			SpiController spiController = SpiController.GetDefaultAsync().AsTask().GetAwaiter().GetResult();
			var settings = new SpiConnectionSettings(0) // GPIO8 Electronic Tricks
			{
				ClockFrequency = 500000,
				Mode = SpiMode.Mode0,   // From SemTech docs pg 80 CPOL=0, CPHA=0
			};

			SpiDevice Device = spiController.GetDevice(settings);

			while (true)
			{
				byte[] writeBuffer = new byte[] { 0x42 }; // RegVersion
				byte[] readBuffer = new byte[1];

				Device.TransferSequential(writeBuffer, readBuffer);

				byte registerValue = readBuffer[0];
				Debug.WriteLine("Register 0x{0:x2} - Value 0X{1:x2} - Bits {2}", 0x42, registerValue, Convert.ToString(registerValue, 2).PadLeft(8, '0'));

				Thread.Sleep(10000);
			}
		}
	}
}

The debug output confirmed I was reading the right value from the RegVer register

Register 0x42 - Value 0X12 - Bits 00010010
Register 0x42 - Value 0X12 - Bits 00010010
Register 0x42 - Value 0X12 - Bits 00010010
Register 0x42 - Value 0X12 - Bits 00010010
Register 0x42 - Value 0X12 - Bits 00010010
Register 0x42 - Value 0X12 - Bits 00010010
Register 0x42 - Value 0X12 - Bits 00010010
Register 0x42 - Value 0X12 - Bits 00010010

The antenna connector not clearing the USB socket is an issue which I’ll solve with a socket like the one on the GrovePI which has longer leads and acts as a spacer.
ElectronicTricksLoraShield