#include <heltec.h>
#include <lmic.h>
#include <hal/hal.h>
#include <SPI.h>
#include <Arduino.h>
#include <math.h>
#include "esp_deep_sleep.h"
#include <driver/adc.h>
#include <driver/dac.h>
#define uS_TO_S_FACTOR 1000000 /* Conversion factor for micro seconds to seconds */
#define TIME_TO_SLEEP 30 /* Time ESP32 will go to sleep (in seconds) */
// Schedule TX every this many seconds (might become longer due to duty cycle limitations).
//const unsigned TX_INTERVAL = 60 * 30;
const unsigned TX_INTERVAL = 60;
// This EUI must be in little-endian format, so least-significant-byte
// first. When copying an EUI from ttnctl output, this means to reverse
// the bytes. For TTN issued EUIs the last bytes should be 0xD5, 0xB3,
// 0x70.
static const u1_t PROGMEM APPEUI[8] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
void os_getArtEui (u1_t* buf) {
memcpy_P(buf, APPEUI, 8);
}
// This should also be in little endian format, see above.
static const u1_t PROGMEM DEVEUI[8] = { //add dev eui here };
void os_getDevEui (u1_t* buf) {
memcpy_P(buf, DEVEUI, 8);
}
// This key should be in big endian format (or, since it is not really a
// number but a block of memory, endianness does not really apply). In
// practice, a key taken from ttnctl can be copied as-is.
static const u1_t PROGMEM APPKEY[16] = { //add app key here };
void os_getDevKey (u1_t* buf) {
memcpy_P(buf, APPKEY, 16);
}
const uint8_t PACKET_SIZE = 8;
uint8_t fullPayload[PACKET_SIZE];
static osjob_t sendjob;
// Pin mapping for Heltec ESP32 and Wireless Stick Lite
const lmic_pinmap lmic_pins = {
.nss = 18, //CS pin
.rxtx = LMIC_UNUSED_PIN,
.rst = 14, //RST PIN
//.dio = {26, 35, 34}, //DIO 0, 1, 2
.dio = {26, 35, LMIC_UNUSED_PIN}, //DIO 0, 1, 2
};
// save the session info in RTC memory during deep sleep
RTC_DATA_ATTR u4_t netid = 0;
RTC_DATA_ATTR devaddr_t devaddr = 0;
RTC_DATA_ATTR u1_t nwkKey[16];
RTC_DATA_ATTR u1_t artKey[16];
RTC_DATA_ATTR bool isShutdown = false;
RTC_DATA_ATTR u4_t sequence_up = 0;
RTC_DATA_ATTR u4_t sequence_dn = 0;
void printSessionInfo() {
Serial.print("netid: ");
Serial.println(netid, DEC);
Serial.print("devaddr: ");
Serial.println(devaddr, HEX);
Serial.print("appSessionKey: ");
for (int i = 0; i < sizeof(artKey); ++i) {
Serial.print(artKey[i], HEX);
}
Serial.println("");
Serial.print("netSessiomKey: ");
for (int i = 0; i < sizeof(nwkKey); ++i) {
Serial.print(nwkKey[i], HEX);
}
Serial.println("");
Serial.print("sequence up: ");
Serial.println(sequence_up, DEC);
Serial.print("sequence dn: ");
Serial.println(sequence_dn, DEC);
Serial.println("");
}
void shutDownRadio() {
Serial.println(F("Shutting LMIC Down"));
sequence_up = LMIC.seqnoUp;
sequence_dn = LMIC.seqnoDn;
LMIC_shutdown();
isShutdown = true;
}
void onEvent (ev_t ev) {
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"));
LMIC_getSessionKeys(&netid, &devaddr, nwkKey, artKey);
printSessionInfo();
LMIC_setLinkCheckMode(0);
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"));
break;
case EV_TXCOMPLETE:
Serial.println(F("EV_TXCOMPLETE Done Sending data (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(F("Shutting LMIC Down"));
sequence_up = LMIC.seqnoUp;
sequence_dn = LMIC.seqnoDn;
Serial.print("LMIC sequence up number:");
Serial.println (sequence_up);
Serial.print("LMIC sequence dn number:");
Serial.println(sequence_dn);
LMIC_shutdown();
isShutdown = true;
Serial.println(F("Going to sleep now"));
Serial.flush();
pinMode(25, OUTPUT); digitalWrite(25, LOW); //The on board LED will be OFF in wake up period
delay(100);
pinMode(23, INPUT);
pinMode(36, INPUT);
pinMode(37, INPUT);
pinMode(38, INPUT);
pinMode(39, INPUT);
pinMode(4, INPUT);
pinMode(2, INPUT);
pinMode(15, INPUT);
pinMode(32, INPUT);
pinMode(33, INPUT);
pinMode(25, INPUT);
pinMode(9, INPUT);
pinMode(10, INPUT);
adc_power_off();
esp_deep_sleep_start();
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;
case EV_SCAN_FOUND:
Serial.println(F("EV_SCAN_FOUND"));
break;
case EV_TXSTART:
Serial.println(F("EV_TXSTART"));
break;
default:
break;
}
}
void initLoraRadio() {
dac_i2s_disable();
// LMIC init
Serial.println("LMIC: Initializing...");
os_init();
// Reset the MAC state. Session and pending data transfers will be discarded.
Serial.println("LMIC: Reseting...");
LMIC_reset();
// this is hack to correct timing for RX1 and RX2 receive window
LMIC_setClockError(5 * MAX_CLOCK_ERROR / 100);
//For CFG_us915 -
LMIC_selectSubBand(1);
if (isShutdown) {
isShutdown = false;
Serial.println("Was shutdown..set session");
printSessionInfo();
LMIC_setSession(netid, devaddr, nwkKey, artKey);
LMIC_setSeqnoUp(sequence_up);
LMIC.seqnoDn = sequence_dn;
}
}
void print_wakeup_reason() {
esp_sleep_wakeup_cause_t wakeup_reason;
wakeup_reason = esp_sleep_get_wakeup_cause();
switch (wakeup_reason)
{
case ESP_SLEEP_WAKEUP_EXT0 : Serial.println("Wakeup caused by external signal using RTC_IO"); break;
case ESP_SLEEP_WAKEUP_EXT1 : Serial.println("Wakeup caused by external signal using RTC_CNTL"); break;
case ESP_SLEEP_WAKEUP_TIMER : Serial.println("Wakeup caused by timer"); break;
case ESP_SLEEP_WAKEUP_TOUCHPAD : Serial.println("Wakeup caused by touchpad"); break;
case ESP_SLEEP_WAKEUP_ULP : Serial.println("Wakeup caused by ULP program"); break;
default : Serial.printf("Wakeup was not caused by deep sleep: %d\n", wakeup_reason); break;
}
}
void setup() {
Serial.begin(9600);
delay(4000);
adc_power_on();
print_wakeup_reason();
esp_sleep_enable_timer_wakeup(TIME_TO_SLEEP * uS_TO_S_FACTOR);
esp_deep_sleep_pd_config(ESP_PD_DOMAIN_RTC_PERIPH, ESP_PD_OPTION_OFF);
Serial.println("Setup ESP32 to sleep for every " + String(TIME_TO_SLEEP) + " Seconds");
Serial.println("STARTING...");
initLoraRadio();
Serial.println("LMIC: Starting...");
do_send(&sendjob);
}
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 {
Serial.println("[do_send] Get sensor data...");
get_sensor_data();
LMIC_setTxData2(1, fullPayload, sizeof(fullPayload), 0);
}
// Next TX is scheduled after TX_COMPLETE event.
}
void get_sensor_data() {
uint16_t l, p;
int8_t t, h, m, g;
// some fake data
t = 21;
p = 1012;
h = 45;
m = 75;
g = 17;
l = 1234;
fullPayload[0] = t;
fullPayload[1] = h;
fullPayload[2] = lowByte(p);
fullPayload[3] = highByte(p);
fullPayload[4] = m;
fullPayload[5] = g;
fullPayload[6] = lowByte(l);
fullPayload[7] = highByte(l);
}
void loop() {
os_runloop_once();
}
This is the sample code, including some attempts at powering down components of the board to improve the low power current. The lowest I could get was 1.5mA which is really far from the 30uA they claimed. I even tried to use their own sample app (not using any LoraWAN) and couldn’t get that low. But the join before and after sleep works well.
One other thing I forgot to mention is the use of
LMIC_setClockError(5 * MAX_CLOCK_ERROR / 100);
I had to increase the error tolerance rate to compensate for the arduino internal oscillator lack of precision.
And in addition to this, make sure your device is at least 3m away from the gateway you are testing with to prevent the end device signal to bounce back. Also I have my loraserver DeviceProfile_Otaa profile configure with LoraWAN MAC version 1.0.2. I am not sure if the latest version of LMIC supports 1.0.3.
There are lots of small details and lots of trial and error 
and 