RFM95W and LMIC

Good morning,
I am using an Arduino Mega 2560 board with a LoRa Shield having the RFM95W radio module. However I use LMIC to send my data to a Dragino LPS8N gateway.
And when I upload my program to the Arduino board nothing happens and I get the error displayed on the serial monitor:
Arduino\libraries\LMIC-Arduino\src\lmic\radio.c:689

I thought at first it was a pin mapping problem but I still have the same problem.
Help me please.
Here is my test code on arduino:

//Smart Waste
const int test =13;
//---------------------------------------------------

#include <lmic.h>
#include <hal/hal.h>
#include <SPI.h>

// LoRaWAN NwkSKey, network session key
// This is the default Semtech key, which is used by the early prototype TTN
// network.
static const PROGMEM u1_t NWKSKEY[16] = { 0x91, 0xA4, 0xAE, 0x05, 0x61, 0x89, 0x16, 0xCF, 0x09, 0x73, 0x51, 0x70, 0x19, 0xD1, 0xC3, 0xE2 };

// LoRaWAN AppSKey, application session key
// This is the default Semtech key, which is used by the early prototype TTN
// network.
static const u1_t PROGMEM APPSKEY[16] = { 0x79, 0xDB, 0xD8, 0xE4, 0x98, 0xF8, 0x19, 0xE1, 0xA6, 0x52, 0x5D, 0x4F, 0x79, 0x43, 0x71, 0x5D };

// LoRaWAN end-device address (DevAddr)
static const u4_t DEVADDR = 0x010C2D70; // <-- Change this address for every node!

// These callbacks are only used in over-the-air activation, so they are
// left empty here (we cannot leave them out completely unless
// DISABLE_JOIN is set in config.h, otherwise the linker will complain).
void os_getArtEui (u1_t* buf) { }
void os_getDevEui (u1_t* buf) { }
void os_getDevKey (u1_t* buf) { }

static uint8_t mydata[] = "Hello, world!";
static osjob_t sendjob;

// Schedule TX every this many seconds (might become longer due to duty
// cycle limitations).
const unsigned TX_INTERVAL = 10;

// Pin mapping
const lmic_pinmap lmic_pins = {
.nss = 10,
.rxtx = LMIC_UNUSED_PIN,
.rst = 9,
.dio = {2, 6, 7},
};

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"));
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 (includes waiting for RX windows)"));
if (LMIC.txrxFlags & TXRX_ACK)
Serial.println(F("Received ack"));
if (LMIC.dataLen) {
Serial.println(F("Received "));
Serial.println(LMIC.dataLen);
Serial.println(F(" bytes of payload"));
}
// Schedule next transmission
os_setTimedCallback(&sendjob, os_getTime()+sec2osticks(TX_INTERVAL), do_send);
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){
// Check if there is not a current TX/RX job running
if (LMIC.opmode & OP_TXRXPEND) {
Serial.println(F("OP_TXRXPEND, not sending"));
} else {

     uint8_t buff[3];
    
     buff[0] = 1;
    LMIC_setTxData2(1, buff, sizeof(buff), 0);
    Serial.println(F("Packet queued"));
}
// Next TX is scheduled after TX_COMPLETE event.

}

void setup() {
Serial.begin(115200);
#ifdef VCC_ENABLE
// For Pinoccio Scout boards
pinMode(VCC_ENABLE, OUTPUT);
digitalWrite(VCC_ENABLE, HIGH);
delay(1000);
#endif
//----------------------------------------------------
pinMode(test, OUTPUT);

// LMIC init
os_init();
// Reset the MAC state. Session and pending data transfers will be discarded.
LMIC_reset();
LMIC_setClockError(MAX_CLOCK_ERROR * 10 / 100);
// Set static session parameters. Instead of dynamically establishing a session
// by joining the network, precomputed session parameters are be provided.
#ifdef PROGMEM
// On AVR, these values are stored in flash and only copied to RAM
// once. Copy them to a temporary buffer here, LMIC_setSession will
// copy them into a buffer of its own again.
uint8_t appskey[sizeof(APPSKEY)];
uint8_t nwkskey[sizeof(NWKSKEY)];
memcpy_P(appskey, APPSKEY, sizeof(APPSKEY));
memcpy_P(nwkskey, NWKSKEY, sizeof(NWKSKEY));
LMIC_setSession (0x1, DEVADDR, nwkskey, appskey);
#else
// If not running an AVR with PROGMEM, just use the arrays directly
LMIC_setSession (0x1, DEVADDR, NWKSKEY, APPSKEY);
#endif

#if defined(CFG_eu868)
// Set up the channels used by the Things Network, which corresponds
// to the defaults of most gateways. Without this, only three base
// channels from the LoRaWAN specification are used, which certainly
// works, so it is good for debugging, but can overload those
// frequencies, so be sure to configure the full frequency range of
// your network here (unless your network autoconfigures them).
// Setting up channels should happen after LMIC_setSession, as that
// configures the minimal channel set.
// NA-US channels 0-71 are configured automatically
LMIC_setupChannel(0, 868100000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
LMIC_setupChannel(1, 868300000, DR_RANGE_MAP(DR_SF12, DR_SF7B), BAND_CENTI);      // g-band
LMIC_setupChannel(2, 868500000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
LMIC_setupChannel(3, 867100000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
LMIC_setupChannel(4, 867300000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
LMIC_setupChannel(5, 867500000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
LMIC_setupChannel(6, 867700000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
LMIC_setupChannel(7, 867900000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
LMIC_setupChannel(8, 868800000, DR_RANGE_MAP(DR_FSK,  DR_FSK),  BAND_MILLI);      // g2-band
// TTN defines an additional channel at 869.525Mhz using SF9 for class B
// devices' ping slots. LMIC does not have an easy way to define set this
// frequency and support for class B is spotty and untested, so this
// frequency is not configured here.
#elif defined(CFG_us915)
// NA-US channels 0-71 are configured automatically
// but only one group of 8 should (a subband) should be active
// TTN recommends the second sub band, 1 in a zero based count.
// https://github.com/TheThingsNetwork/gateway-conf/blob/master/US-global_conf.json
LMIC_selectSubBand(1);
#endif

// Disable link check validation
LMIC_setLinkCheckMode(0);

// TTN uses SF9 for its RX2 window.
LMIC.dn2Dr = DR_SF9;

// Set data rate and transmit power for uplink (note: txpow seems to be ignored by the library)
LMIC_setDrTxpow(DR_SF7,14);

// Start job

do_send(&sendjob);

}

//----------------------------------------------------------------------
void loop() {
// put your main code here, to run repeatedly:
os_runloop_once();
digitalWrite(test,HIGH);
delay(1000);
digitalWrite(test,LOW);
delay(1000);

}
//------------------------------------------------------------------

Unclear what you mean by that, more details ?

Is the 'LoRa Shield having the RFM95W radio module' definetly compatible with a Mega ?

Not a good idea to use such a short TX_INTERVAL, 10 seconds, if run all the time the node would exceed the TTN fair use limit by a huge amount.

When I say "lora shiel with RFM95W" I mean that the LoRa shield I was using was from dragino and it was SX1276 instead of RFM95W.
For compatibility I saw some that it was not but on other forums I saw that it was possible.
I am a little lost.
I am not an LMIC expert, which is why I could be wrong and I count on your technical support.
And so what is the correct duration for the TX_INTERVAL?

So is the forum, we have no idea which shield you are using, so provide a link or picture.

For free access to TTN your limited to 30 seconds air time a day. So because the air time per packet varies depending on how far you are from the Gateway, the interval should be changed accordingly. Unfortunatly LMIC does not allow for the interval to be automatically adjusted.

A interval of 5 to 15 minutes might be more friendly. If you want to send more often then contact TTI and set up a paid account.

For the link I can no longer find the equipment on the sales site.
Here is the photo:

Ok I will then change the duration. My gateway is right next to the transmitter I use a private server called Chirpstack.

If your using Chirpstack, then your not using TTN.

Yes, I don't use TTN. My problem is the connection between my arduino card and the gateway LoRa.

Unclear if its Mega compatible.

It looks like it has the connector to get the SPI connections from the 6 pin SPI\ISP connector however.

You should check that the SPI connections SCK,MOSI,MISO on the LoRa module are connected to the SPI\ISP connector.

Sorry I'm a debutant so I don't fully understand. Are you talking about the pins that are below the card?

What is surprising is when I upload the program to the Arduino Mego board even if there is no lora shield, nothing happens. The program does not run.

In the picture of the Mega, the SPI\ISP connector is the 6 pins to the left of the Microcontoller.

Or just try one of the examples from a normal LoRa library, the examples normally tell you if the LoRa device is not responding.

OK, I'll do that and I'll give you a feedback. What do you advise me as a lora library?

The most common LoRa library seen on here can be installed from the IDE, Tools\Manage Libraries, search for a library that is called 'LoRa'

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