This is the sketch i’ve been using:
#include <arduino_lmic.h>
#include <arduino_lmic_hal_boards.h>
#include <arduino_lmic_hal_configuration.h>
#include <arduino_lmic_lorawan_compliance.h>
#include <arduino_lmic_user_configuration.h>
#include <lmic.h>
#include <hal/hal.h>
#include <SPI.h>
#include <MHZ19.h>
#include <SoftwareSerial.h>
#include “heltec.h”
#include “DHT.h”
#define DHTTYPE DHT22
#define DHTPIN 13
#define RXPin 22 // para MH-Z19B
#define TXPin 21 // para MH-Z19B
SoftwareSerial ss(RXPin, TXPin);// RX, TX
MHZ19 mhz(&ss);
DHT dht(DHTPIN, DHTTYPE);
/long val_CO2 = 0; // valor CO2
float val_tempC = 0.0; // valor Temperatura
float val_accCO2 = 0.0; // valor accuracy
long val_minCO2 = 0.0; // valor min CO2/
unsigned long getDataTimer;
unsigned long counter;
unsigned long paquete;
float h;
float t;
float CO2;
long val_CO2 = 0; // valor CO2
float val_tempC = 0.0; // valor Temperatura
float val_accCO2 = 0.0; // valor accuracy
unsigned long MHZ19B_PREHEATING_TIME = 180000; // Por especificaciones tiene un PREHEATING Time de 3 minutos… pero pongo 1…
const int OFFSET_TEMP = -1; // Valor obtenido de comparar con un termometro.
const int OFFSET_CO2 = +18; // Valor de 400 al arranque +18 que se supone media anual al nivel del mar en 2020
/*#ifdef COMPILE_REGRESSION_TEST
define FILLMEIN 0
#else
warning “You must replace the values marked FILLMEIN with real values from the TTN control panel!”
define FILLMEIN (#dont edit this, edit the lines that use FILLMEIN)
#endif*/
// lsb
static const u1_t PROGMEM APPEUI[8] = { 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX };
void os_getArtEui (u1_t* buf) {
memcpy_P(buf, APPEUI, 8);
}
// lsb
static const u1_t PROGMEM DEVEUI[8] = { 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX };
void os_getDevEui (u1_t* buf) {
memcpy_P(buf, DEVEUI, 8);
}
// msb
static const u1_t PROGMEM APPKEY[16] = { 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX };
void os_getDevKey (u1_t* buf) {
memcpy_P(buf, APPKEY, 16);
}
// payload to send to TTN gateway
static uint8_t payload[8];
static osjob_t sendjob;
// Schedule TX every this many seconds (might become longer due to duty
// cycle limitations).
const unsigned TX_INTERVAL = 60;
// Pin mapping
const lmic_pinmap lmic_pins = {
.nss = 18,
.rxtx = LMIC_UNUSED_PIN,
.rst = 14, // reset pinPreformatted text
.dio = {/dio0/ 26, /dio1/ 35, /dio2/ 33}
};
void printHex2(unsigned v) {
v &= 0xff;
if (v < 16)
Serial.print(‘0’);
Serial.print(v, HEX);
}
void onEvent (ev_t ev) {
Serial.print(os_getTime());
Serial.print(": ");
switch (ev) {
case EV_SCAN_TIMEOUT:
Serial.println(F(“EV_SCAN_TIMEOUT”));
break;
case EV_BEACON_FOUND:
Serial.println(F(“EV_BEACON_FOUND”));
break;
case EV_BEACON_MISSED:
Serial.println(F(“EV_BEACON_MISSED”));
break;
case EV_BEACON_TRACKED:
Serial.println(F(“EV_BEACON_TRACKED”));
break;
case EV_JOINING:
Serial.println(F(“EV_JOINING”));
break;
case EV_JOINED:
Serial.println(F(“EV_JOINED”));
{
u4_t netid = 0;
devaddr_t devaddr = 0;
u1_t nwkKey[16];
u1_t artKey[16];
LMIC_getSessionKeys(&netid, &devaddr, nwkKey, artKey);
Serial.print("netid: ");
Serial.println(netid, DEC);
Serial.print(“devaddr: “);
Serial.println(devaddr, HEX);
Serial.print(“AppSKey: “);
for (size_t i = 0; i < sizeof(artKey); ++i) {
if (i != 0)
Serial.print(”-”);
printHex2(artKey[i]);
}
Serial.println(””);
Serial.print(“NwkSKey: “);
for (size_t i = 0; i < sizeof(nwkKey); ++i) {
if (i != 0)
Serial.print(”-”);
printHex2(nwkKey[i]);
}
Serial.println();
}
// Disable link check validation (automatically enabled
// during join, but because slow data rates change max TX
// size, we don’t use it in this example.
LMIC_setLinkCheckMode(0);
break;
/*
|| This event is defined but not used in the code. No
|| point in wasting codespace on it.
||
|| case EV_RFU1:
|| Serial.println(F(“EV_RFU1”));
|| break;
*/
case EV_JOIN_FAILED:
Serial.println(F(“EV_JOIN_FAILED”));
break;
case EV_REJOIN_FAILED:
Serial.println(F(“EV_REJOIN_FAILED”));
break;
case EV_TXCOMPLETE:
Serial.println(F(“EV_TXCOMPLETE (includes waiting for RX windows)”));
if (LMIC.txrxFlags & TXRX_ACK)
Serial.println(F(“Received ack”));
if (LMIC.dataLen) {
Serial.print(F(“Received “));
Serial.print(LMIC.dataLen);
Serial.println(F(” bytes of payload”));
}
// Schedule next transmission
os_setTimedCallback(&sendjob, os_getTime() + sec2osticks(TX_INTERVAL), do_send);
Serial.println("\n PAQUETE ENVIADO ");
paquete++;
break;
case EV_LOST_TSYNC:
Serial.println(F("EV_LOST_TSYNC"));
break;
case EV_RESET:
Serial.println(F("EV_RESET"));
break;
case EV_RXCOMPLETE:
// data received in ping slot
Serial.println(F("EV_RXCOMPLETE"));
break;
case EV_LINK_DEAD:
Serial.println(F("EV_LINK_DEAD"));
break;
case EV_LINK_ALIVE:
Serial.println(F("EV_LINK_ALIVE"));
break;
/*
|| This event is defined but not used in the code. No
|| point in wasting codespace on it.
||
|| case EV_SCAN_FOUND:
|| Serial.println(F("EV_SCAN_FOUND"));
|| break;
*/
case EV_TXSTART:
Serial.println(F("EV_TXSTART"));
break;
case EV_TXCANCELED:
Serial.println(F("EV_TXCANCELED"));
break;
case EV_RXSTART:
/* do not print anything -- it wrecks timing */
break;
case EV_JOIN_TXCOMPLETE:
Serial.println(F("EV_JOIN_TXCOMPLETE: no JoinAccept"));
break;
default:
Serial.print(F("Unknown event: "));
Serial.println((unsigned) ev);
break;
}
}
void do_send(osjob_t* j) {
// Check if there is not a current TX/RX job running
if (LMIC.opmode & OP_TXRXPEND) {
Serial.println(F(“OP_TXRXPEND, not sending”));
} else {
// CO2 //
CO2 = mhz.getCO2();
Serial.print("Co2 ");
Serial.println(CO2);
// TEMPERATURE //
t = dht.readTemperature();
Serial.print("Temperatura: ");
Serial.println(t);
// HUMIDITY //
h = dht.readHumidity();
Serial.print("Humedad: ");
Serial.println(h);
if (isnan(h) || isnan(t)) {
Serial.println(F("Failed to read from DHT sensor!"));
return;
}
uint16_t ft = (uint16_t)(t * 100);
uint16_t fh = (uint16_t)(h * 100);
uint32_t fco2 = (uint32_t)((CO2 + OFFSET_CO2) * 100);
payload[0] = ft >> 8;
payload[1] = ft % 0xFF;
payload[2] = fh >> 8;
payload[3] = fh & 0xFF;
payload[4] = fco2 & 0xFF;
payload[5] = (fco2 >> 8) & 0xFF;
payload[6] = (fco2 >> 16) & 0xFF;
payload[7] = (fco2 >> 24) & 0xFF;
// Prepare upstream data transmission at the next possible time.
LMIC_setTxData2(1, payload, sizeof(payload) - 1, 0);
Serial.println(F("Packet queued"));
}
// Next TX is scheduled after TX_COMPLETE event.
}
void setup() {
Heltec.begin(true /DisplayEnable Enable/, true /LoRa Enable/, true /Serial Enable/, true /LoRa use PABOOST/, 868E6 /LoRa RF working band/);
Serial.begin(115200);
delay(1000);
ss.begin(9600); // Software Serial
Serial.println(F(“Starting\n”));
dht.begin();
mhz.setAutoCalibration(true); // default settings - off autocalibration
// LMIC init
os_init();
// Reset the MAC state. Session and pending data transfers will be discarded.
LMIC_reset();
// Start job (sending automatically starts OTAA too)
do_send(&sendjob);
}
void loop() {
os_runloop_once();
if (millis() - getDataTimer >= 3000) {
val_tempC = mhz.getTemperature() + OFFSET_TEMP;
val_CO2 = mhz.getCO2() + OFFSET_CO2;
val_accCO2 = mhz.getAccuracy();
MHZ19_RESULT response = mhz.retrieveData();
if (response == MHZ19_RESULT_OK) {
Serial.print(F("\n\nCO2: "));
Serial.println(val_CO2);
Heltec.display -> clear();
Heltec.display -> drawString(0, 0, "Co2: " + String(val_CO2) + " ppm");
Heltec.display -> drawString(0, 10, "Nº de medidas: " + String(counter));
Heltec.display -> drawString(0, 20, "Paquetes enviados: " + String(paquete));
Heltec.display -> display();
}
else {
Serial.print( "Error Reading MH-Z19B Module" );
Serial.print(F("Error, code: "));
Serial.println(response);
Heltec.display -> clear();
Heltec.display -> drawString(0, 0, "ERROR en medición: " + String(response));
Heltec.display -> drawString(0, 10, "Nº de medidas: " + String(counter));
Heltec.display -> drawString(0, 20, "Paquetes enviados: " + String(paquete));
Heltec.display -> display();
}
counter++;
recogerTemp();
getDataTimer = millis();
}
}
void recogerTemp() {
h = dht.readHumidity();
t = dht.readTemperature();
if (isnan(h) || isnan(t)) {
Serial.println(F(“Failed to read from DHT sensor!”));
return;
}
Serial.print(F("\n\nHumedad: “));
Serial.print(h);
Serial.print(F(”% Temperatura: "));
Serial.print(t);
Serial.println(F("°C "));
Heltec.display -> drawString(0, 30, “Temperatura: " + String(t) + " ºC”);
Heltec.display -> drawString(0, 40, “Humedad: " + String(h) + " %”);
Heltec.display -> display();
}
It works perfectly, any questions you may have, don’t hesitate to ask!
@omb @njotha
