Hi! I'm currently trying to read gas sensor readings from a MQ2 gas sensor that is mounted on a RAK 4631 and then send the signals to a Lora32 T-beam. I'm just wondering would it work since the RAK 4631 and Lora32 are using 2 different libraries.
For the RAK, I'm using the sx126x-Arduino library and for the T-beam, I am planning to use the Lora Library by sandeepmistry. I believe I am almost done with the code for the transmitter and I'm wondering if I'm on the right track. Thank you so much for any input.
#include <Adafruit_TinyUSB.h>
#include <SX126x-RAK4630.h>
#include <SPI.h>
#include <Wire.h>
#include "ADC121C021.h"
#include <U8g2lib.h> // Click to install library: http://librarymanager/All#u8g2
//defining the functions for reading the gas sensor values
#define EN_PIN WB_IO6 //Logic high enables the device. Logic low disables the device
#define ALERT_PIN WB_IO5 //a high indicates that the respective limit has been violated.
#define MQ2_ADDRESS 0x51 //the device i2c address
#define RatioMQ2CleanAir (1.0) //RS / R0 = 1.0 ppm
#define MQ2_RL (10.0) //the board RL = 10KΩ can adjust
//defining the parameters for the lora peer to peer communication
// Define LoRa parameters
#define RF_FREQUENCY 923000000 // Hz
#define TX_OUTPUT_POWER 22 // dBm
#define LORA_BANDWIDTH 0 // [0: 125 kHz, 1: 250 kHz, 2: 500 kHz, 3: Reserved]
#define LORA_SPREADING_FACTOR 7 // [SF7..SF12]
#define LORA_CODINGRATE 1 // [1: 4/5, 2: 4/6, 3: 4/7, 4: 4/8]
#define LORA_PREAMBLE_LENGTH 8 // Same for Tx and Rx
#define LORA_SYMBOL_TIMEOUT 0 // Symbols
#define LORA_FIX_LENGTH_PAYLOAD_ON false
#define LORA_IQ_INVERSION_ON false
#define RX_TIMEOUT_VALUE 5000 //changed from original value of 3000
#define TX_TIMEOUT_VALUE 5000 //changed from original value of 3000
//Lora function declarations
void OnTxDone(void);
void OnTxTimeout(void);
#ifdef NRF52_SERIES
#define LED_BUILTIN 35
#endif
//for mq2 sensor
ADC121C021 MQ2;
uint16_t result;
//for lorawan sensor
static RadioEvents_t RadioEvents;
static uint8_t TxdBuffer[64];
void setup()
{
//mq2 sensor start
pinMode(ALERT_PIN, INPUT);
pinMode(EN_PIN, OUTPUT);
digitalWrite(EN_PIN, HIGH); //power on RAK12004
delay(5);
//initialize the lora chip
lora_rak4630_init();
time_t timeout = millis();
Serial.begin(115200);
while (!Serial)
{
delay(100); //delaying for 100 milliseconds indefinitely
}
//********ADC121C021 ADC convert init ********************************
while (!(MQ2.begin(MQ2_ADDRESS, Wire)))
{
Serial.println("please check device!!!");
delay(200);
}
Serial.println("MQ2 gas sensor seems to be working fine");
//testing the lora p2p test
Serial.println("============");
Serial.println("Lorap2p Tx Test");
Serial.println("=========");
//Initialize radio call backs
RadioEvents.TxDone = OnTxDone;
RadioEvents.RxDone = NULL; //since this is for transmission
RadioEvents.TxTimeout = OnTxTimeout;
RadioEvents.RxTimeout = NULL;
RadioEvents.RxError = NULL;
//Initialize the radio
Radio.Init(&RadioEvents);
//Set the radio channel
Radio.SetChannel(RF_FREQUENCY);
//Set Radio Tx configuration
Radio.SetTxConfig(MODEM_LORA, TX_OUTPUT_POWER, 0 , LORA_BANDWIDTH, LORA_SPREADING_FACTOR, LORA_CODINGRATE, LORA_PREAMBLE_LENGTH, LORA_FIX_LENGTH_PAYLOAD_ON, true, 0, 0, LORA_IQ_INVERSION_ON, TX_TIMEOUT_VALUE);
send();
delay(3000);
//sending some data to establish connection
//**************init MQ2 *****************************************************
MQ2.setRL(MQ2_RL);
/*
*detect Propane gas if to detect other gas need to reset A and B value，it depend on MQ sensor datasheet
*/
MQ2.setA(-0.890); //A -> Slope, -0.685
MQ2.setB(1.125); //B -> Intersect with X - Axis 1.019
//Set math model to calculate the PPM concentration and the value of constants
MQ2.setRegressionMethod(0); //PPM = pow(10, (log10(ratio)-B)/A)
float calcR0 = 0;
for (int i = 1; i <= 100; i++)
{
calcR0 += MQ2.calibrateR0(RatioMQ2CleanAir);
}
MQ2.setR0(calcR0 / 10);
if (isinf(calcR0))
{
Serial.println("Warning: Conection issue founded, R0 is infite (Open circuit detected) please check your wiring and supply");
while (1)
;
}
if (calcR0 == 0)
{
Serial.println("Warning: Conection issue founded, R0 is zero (Analog pin with short circuit to ground) please check your wiring and supply");
while (1)
;
}
float r0 = MQ2.getR0();
Serial.printf("R0 Value is:%3.2f\r\n", r0);
}
void loop()
{
float sensorPPM;
float PPMpercentage;
//handle radio events
Radio.IrqProcess();
Serial.println("Getting Conversion Readings from ADC121C021");
Serial.println(" ");
sensorPPM = MQ2.readSensor();
Serial.printf("sensor PPM Value is: %3.2f\r\n", sensorPPM);
PPMpercentage = sensorPPM / 10000;
sensorPPM = round(sensorPPM*100)/100;
Serial.printf ("The new rounded value of sensorPPM is ", sensorPPM); //to test the value of the new rounded file
Serial.printf("PPM percentage Value is:%3.2f%%\r\n", PPMpercentage);
Serial.println(" ");
Serial.println(" *************************** ");
Serial.println(" ");
int intPart = (int)sensorPPM;
float decPart = sensorPPM - (float)intPart;
if (sensorPPM >= 1000 ){
int temp = intPart;
uint8_t ppmbuf[7];
for (int i=3 ; i >=0 ; i--){
ppmbuf[i] = temp % 10;
temp /= 10;
}
ppmbuf[4] = -1;
ppmbuf[5] = (int)(decPart *100) % 10 ;
ppmbuf[6] = (int)(decPart *100) / 10;
Radio.Send(ppmbuf, 7);
}
else {
uint8_t ppmbuf[6];
int temp = intPart;
for (int i=2 ; i >= 0 ; i--){
ppmbuf[i] = temp % 10;
temp = temp / 10;
}
ppmbuf[3] = -1;
ppmbuf[4] = (int)(decPart *100) % 10;
ppmbuf[5] = (int)(decPart *100) / 10;
Radio.Send(ppmbuf, 6);
}
delay(5000);
yield();
}
void OnTxDone(void){
Serial.println("onTxDone");
delay(5000);
send();
}
void OnTxTimeout(void)
{
Serial.println("OnTxTimeout");
}
void send(){
TxdBuffer[0] = 'H';
TxdBuffer[1] = 'e';
TxdBuffer[2] = 'l';
TxdBuffer[3] = 'l';
TxdBuffer[4] = 'o';
Radio.Send(TxdBuffer, 5);
}