Hello everyone.
First of all, sorry if the question has already been asked, I didn’t found an answer to it or perhaps didn’t understood it correctly.
At work, I was given the task to program an eSP32 device with the Arduino LMIC library and the deep sleep feature of the ESP32. It’s a completely unknown field to me.
I took the demo from the library as a basis and tried to adapt it to learn and understand how it works.
The demo works like a charm, I successfully receive the “Hello world” message on either TTN or on the company’s private Chirpstack server I set up.
However, I’m facing an issue as soon as I’m adding deep sleep (I even tried light sleep mode, but I’m facing the same issue).
I’m trying to make the micro-controller sleep after it sends a message, but sometimes the serial console displays “noJoinAccept” and sometimes the message isn’t delivered. It seems very random.
Here’s the example code, (I removed the application/device credentials, as well as a few comments in the beginning for readability).
#include <lmic.h>
#include <hal/hal.h>
#include <SPI.h>
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);}
static const u1_t PROGMEM DEVEUI[8]={ };
void os_getDevEui (u1_t* buf) { memcpy_P(buf, DEVEUI, 8);}
static const u1_t PROGMEM APPKEY[16] = { };
void os_getDevKey (u1_t* buf) { memcpy_P(buf, APPKEY, 16);}
static uint8_t mydata[] = "Hello, world!";
static osjob_t sendjob;
const unsigned TX_INTERVAL = 60;
RTC_DATA_ATTR int wake_count;
// Pin mapping
const lmic_pinmap lmic_pins = {
.nss = 18,
.rxtx = LMIC_UNUSED_PIN,
.rst = 23,
.dio = {26, 33, 32},
};
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);
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;
/*
|| 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.print(F("Démarrage n°"));
Serial.println(++wake_count);
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 {
// Prepare upstream data transmission at the next possible time.
LMIC_setTxData2(1, mydata, sizeof(mydata)-1, 0);
Serial.println(F("Packet queued"));
}
// Next TX is scheduled after TX_COMPLETE event.
}
void setup() {
Serial.begin(115200);
Serial.println(F("Starting"));
esp_sleep_enable_timer_wakeup(120000000);
#ifdef VCC_ENABLE
// For Pinoccio Scout boards
pinMode(VCC_ENABLE, OUTPUT);
digitalWrite(VCC_ENABLE, HIGH);
delay(1000);
#endif
Serial.println(F("Before os_init()"));
// LMIC init
os_init();
Serial.println(F("After os_init()"));
Serial.println(F("Before LMIC_reset()"));
// Reset the MAC state. Session and pending data transfers will be discarded.
LMIC_reset();
Serial.println(F("After LMIC_reset()"));
// Start job (sending automatically starts OTAA too)
do_send(&sendjob);
}
void loop() {
os_runloop_once();
}
My board is a TTGO ESP32 Lora.
Thanks by advance for your help 
, I can provide any extra info if needed.
Clément