ATMEGA1284p with RFM95Hope

Hi Guys,

I am using a custom PCB with an ATMEGA1284p and an RFM95Hope.

I have previously used version 2.3.2 of the lmic library and ported to 4.0.0 now.

I’ve tried adding a device to v3 over ABP using the devEUI of a dummydevice on v2.

I have adapted the ttn-abp code example according to my settings:

 * Copyright (c) 2015 Thomas Telkamp and Matthijs Kooijman
 * Copyright (c) 2018 Terry Moore, MCCI
 * Permission is hereby granted, free of charge, to anyone
 * obtaining a copy of this document and accompanying files,
 * to do whatever they want with them without any restriction,
 * including, but not limited to, copying, modification and redistribution.
 * This example sends a valid LoRaWAN packet with payload "Hello,
 * world!", using frequency and encryption settings matching those of
 * the The Things Network.
 * This uses ABP (Activation-by-personalisation), where a DevAddr and
 * Session keys are preconfigured (unlike OTAA, where a DevEUI and
 * application key is configured, while the DevAddr and session keys are
 * assigned/generated in the over-the-air-activation procedure).
 * Note: LoRaWAN per sub-band duty-cycle limitation is enforced (1% in
 * g1, 0.1% in g2), but not the TTN fair usage policy (which is probably
 * violated by this sketch when left running for longer)!
 * To use this sketch, first register your application and device with
 * the things network, to set or generate a DevAddr, NwkSKey and
 * AppSKey. Each device should have their own unique values for these
 * fields.
 * Do not forget to define the radio type correctly in
 * arduino-lmic/project_config/lmic_project_config.h or from your BOARDS.txt.

 // References:
 // [feather] adafruit-feather-m0-radio-with-lora-module.pdf

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

// For normal use, we require that you edit the sketch to replace FILLMEIN
// with values assigned by the TTN console. However, for regression tests,
// we want to be able to compile these scripts. The regression tests define
// COMPILE_REGRESSION_TEST, and in that case we define FILLMEIN to a non-
// working but innocuous value.
# define FILLMEIN 0
# 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)

// LoRaWAN NwkSKey, network session key
static const PROGMEM u1_t NWKSKEY[16] = { 0x3E, 0xEE, 0x1D, 0xA6, 0x8F, 0xBE, 0x74, 0x25, 0xB3, 0x0B, 0x69, XXX };

// LoRaWAN AppSKey, application session key
static const u1_t PROGMEM APPSKEY[16] = { 0x62, 0x91, 0x68, 0x2C, 0xD7, 0x08, 0x69, 0x3D, 0x94, 0x38, XXX };

// LoRaWAN end-device address (DevAddr)
// See
// The library converts the address to network byte order as needed.
static const u4_t DEVADDR = 0x260XXX; // <-- 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 arduino-lmic/project_config/lmic_project_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[5];
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
// Adapted for Feather M0 per p.10 of [feather]
const lmic_pinmap lmic_pins = {
  .nss = 12,
  .rxtx = LMIC_UNUSED_PIN,
  .rst = 13,
  .dio = {2, 3, 15},

void onEvent (ev_t ev) {
    Serial.print(": ");
    switch(ev) {
        case EV_SCAN_TIMEOUT:
        case EV_BEACON_FOUND:
        case EV_BEACON_MISSED:
        case EV_BEACON_TRACKED:
        case EV_JOINING:
        case EV_JOINED:
        || 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:
        case EV_REJOIN_FAILED:
        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(F(" bytes of payload"));
            // Schedule next transmission
            os_setTimedCallback(&sendjob, os_getTime()+sec2osticks(TX_INTERVAL), do_send);
        case EV_LOST_TSYNC:
        case EV_RESET:
        case EV_RXCOMPLETE:
            // data received in ping slot
        case EV_LINK_DEAD:
        case EV_LINK_ALIVE:
        || 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("Unknown event: "));
            Serial.println((unsigned) ev);

void do_send(osjob_t* j){
    // Check if there is not a current TX/RX job running
    byte temp = 32;
    byte humidity = 15;
    mydata[0] = temp;
    mydata[1] = humidity;
    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() {
//    pinMode(13, OUTPUT); 
    while (!Serial); // wait for Serial to be initialized
    delay(100);     // per sample code on RF_95 test

    #ifdef VCC_ENABLE
    // For Pinoccio Scout boards
    pinMode(VCC_ENABLE, OUTPUT);
    digitalWrite(VCC_ENABLE, HIGH);

    // LMIC init
    // Reset the MAC state. Session and pending data transfers will be discarded.

    // 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 (0x13, DEVADDR, nwkskey, appskey);
    // If not running an AVR with PROGMEM, just use the arrays directly
    LMIC_setSession (0x13, DEVADDR, NWKSKEY, APPSKEY);

    #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.
    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.

    // Disable link check validation

    // 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)

    // Start job

void loop() {
    unsigned long now;
    now = millis();
    if ((now & 512) != 0) {
      digitalWrite(13, HIGH);
    else {
      digitalWrite(13, LOW);

The pinmapping is correct.

The console log looks as follows:

12:00:26.144 -> Packet queued
12:00:28.338 -> 37540405: EV_TXCOMPLETE (includes waiting for RX windows)
12:00:38.358 -> 38166216: EV_TXSTART
12:00:38.358 -> Packet queued
12:00:40.503 -> 38303515: EV_TXCOMPLETE (includes waiting for RX windows)
12:00:50.529 -> 38929323: EV_TXSTART
12:00:50.529 -> Packet queued
12:00:52.708 -> 39066788: EV_TXCOMPLETE (includes waiting for RX windows)

Occasionally the device can send to TTN but very rarely, once it is connected, it can keep sending.

Is there a special reason you’re using ABP?
I would suggest to use this example (read its comments in the code!), and only modify the pin mapping according to your device: arduino-lmic/ttn-otaa.ino at master · mcci-catena/arduino-lmic · GitHub

I’m using v4.0.0 with my custom Atmega1284P boards with OTAA and have no issues.

This is now working as per the OP’s other topic on the MIC mismatch.

1 Like

Thank you @mat89 and @descartes.
@mat89 what board layout are you using? I didn’t use an external oscillator which I think is the reason that the ATMEGA1284p does not receive the acknowledge on the join event.

I’m using the Atmega1284P with an external 8MHz oscillator, this is the board: GitHub - IoTDevicesCH/LoraMidiAtmega1284P: Small Lora(WAN) board using an Atmega1284P chip and RFM95 module

Maybe you can try to increase the receive window for testing purpose, you can do this with the ‘clock error’ with the LMIC_setClockError command.

And in fact, that’s exactly what he did, hence my comment: