This is my code, it’s basically the OTA example code with some stuff added to read from a BMP085 sensor and send data in Cayenne LPP format to TTN:
#include <avr/sleep.h>
#include <avr/wdt.h>
#include <lmic.h>
#include <hal/hal.h>
#include <SPI.h>
#include “LowPower.h”
#include <Wire.h>
#include <Adafruit_BMP085.h>
#include <Arduino.h>
int sleepcycles = 75; // every sleepcycle will last 8 secs, total sleeptime will be sleepcycles * 8 sec
bool joined = false;
bool sleeping = false;
#define LedPin 13
#define VBATPIN A9
static const u1_t DEVEUI[8] = { }; //LSB
static const u1_t APPEUI[8] = { }; //LSB
static const u1_t APPKEY[16] = { }; //MSB
Adafruit_BMP085 bmp;
static void initfunc (osjob_t*);
// provide APPEUI (8 bytes, LSBF)
void os_getArtEui (u1_t* buf) {
memcpy(buf, APPEUI, 8);
}
// provide DEVEUI (8 bytes, LSBF)
void os_getDevEui (u1_t* buf) {
memcpy(buf, DEVEUI, 8);
}
// provide APPKEY key (16 bytes)
void os_getDevKey (u1_t* buf) {
memcpy(buf, APPKEY, 16);
}
static osjob_t sendjob;
static osjob_t initjob;
// Pin mapping is hardware specific.
// Pin mapping
const lmic_pinmap lmic_pins = {
.nss = 8,
.rxtx = LMIC_UNUSED_PIN,
.rst = 4, // Needed on RFM92/RFM95? (probably not) D0/GPIO16
.dio = {7, 6, LMIC_UNUSED_PIN}, // Specify pin numbers for DIO0, 1, 2
// connected to D7, D6, -
};
float getBatVoltage() {
float measuredvbat = analogRead(VBATPIN);
measuredvbat *= 2; // Voltage is devided by two by bridge resistor so multiply back
measuredvbat *= 3.3; // Multiply by 3.3V, our reference voltage
measuredvbat /= 1024; // convert to voltage
Serial.print("VBat: " ); Serial.println(measuredvbat);
return measuredvbat;
}
void onEvent (ev_t ev) {
int i,j;
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”));
// Disable link check validation (automatically enabled
// during join, but not supported by TTN at this time).
LMIC_setLinkCheckMode(0);
digitalWrite(LedPin,LOW);
// after Joining a job with the values will be sent.
joined = true;
break;
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”));
// Re-init
os_setCallback(&initjob, initfunc);
break;
case EV_TXCOMPLETE:
sleeping = true;
if (LMIC.dataLen) {
// data received in rx slot after tx
// if any data received, a LED will blink
// this number of times, with a maximum of 10
Serial.print(F("Data Received: "));
Serial.println(LMIC.frame[LMIC.dataBeg],HEX);
i=(LMIC.frame[LMIC.dataBeg]);
// i (0…255) can be used as data for any other application
// like controlling a relay, showing a display message etc.
if (i>10){
i=10; // maximum number of BLINKs
}
for(j=0;j<i;j++)
{
digitalWrite(LedPin,HIGH);
delay(200);
digitalWrite(LedPin,LOW);
delay(400);
}
}
Serial.println(F(“EV_TXCOMPLETE (includes waiting for RX windows)”));
delay(50); // delay to complete Serial Output before Sleeping
// Schedule next transmission
// next transmission will take place after next wake-up cycle in main loop
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;
default:
Serial.println(F("Unknown event"));
break;
}
}
void do_send(osjob_t* j) {
if (LMIC.opmode & OP_TXRXPEND) {
Serial.println(F(“OP_TXRXPEND, not sending”));
} else {
// Prepare upstream data transmission at the next possible time.
float vbat = getBatVoltage();
int vbatint = (int)(vbat*100);
Serial.print("vbatint: " ); Serial.println(vbatint);
uint8_t message[12];
message[0] = 0x01;
message[1] = 0x02;
message[2] = (uint8_t)highByte(vbatint);
message[3] = (uint8_t)lowByte(vbatint);
int pressure = (int)(bmp.readPressure() / 10);
message[4] = 0x02;
message[5] = 0x73;
message[6] = (uint8_t)highByte(pressure);
message[7] = (uint8_t)lowByte(pressure);
int temperature = (int)((bmp.readTemperature() * 100)/10);
message[8] = 0x03;
message[9] = 0x67;
message[10] = (uint8_t)highByte(temperature);
message[11] = (uint8_t)lowByte(temperature);
LMIC_setTxData2(1, message, sizeof(message), 0);
Serial.println(F("Sending: "));
}
}
// initial job
static void initfunc (osjob_t* j) {
// reset MAC state
LMIC_reset();
LMIC_setClockError(MAX_CLOCK_ERROR * 1 / 100);
// start joining
LMIC_startJoining();
// init done - onEvent() callback will be invoked…
}
void setup()
{
if (!bmp.begin()) {
Serial.println(“Could not find a valid BMP085 sensor, check wiring!”);
while (1) {}
}
delay(10000);
Serial.begin(9600);
Serial.println(F(“Starting”));
delay(10000);
os_init();
// Reset the MAC state. Session and pending data transfers will be discarded.
os_setCallback(&initjob, initfunc);
LMIC_reset();
}
void loop()
{
// start OTAA JOIN
if (joined==false)
{
os_runloop_once();
}
else
{
do_send(&sendjob); // Sent sensor values
while(sleeping == false)
{
os_runloop_once();
}
sleeping = false;
for (int i=0;i<sleepcycles;i++)
{
LowPower.powerDown(SLEEP_8S, ADC_OFF, BOD_OFF); //sleep 8 seconds
}
}
digitalWrite(LedPin,((millis()/100) % 2) && (joined==false)); // only blinking when joining and not sleeping
}
I’ve fixed this now.