Uplink to TTN using LoRa-E5-Dev-Board and Mbed OS

End Devices (Nodes)
1

Hi there,

I am currently working on a project using the LoRa-E5-Dev-Board with Mbed OS, and I need assistance with sending a simple “Hello World” message to The Things Network (TTN). I have encountered issues while using the provided LoRaWAN example, and I’m not receiving any results.

2

Which example where?

This could have so many possible meanings. Can you tell us what is happening?

Sending text is hugely inefficient and becomes a bad habit - just send a single random number!


Please have a look at some of the other requests for assistance on the forum so you can see what is an appropriate level of detail and supporting material that is required - links to code, logs formatted with the </> tool etc etc.

2 Likes
3

Hi , Thanks for your suggestions. Here is the detailed information about my issue:

I am trying to send a simple “Hello TTN” message to The Things Network (TTN) using ABP activation. Below is the code I am using:

#include “mbed.h”
#include “LoRaWANInterface.h”
#include “lorawan/lorawan_types.h”
#include “events/EventQueue.h”
#include “trace_helper.h”
#include “lora_radio_helper.h”
#include “mbedtls_lora_config.h” // Inclusion de la configuration mbedtls

// Configuration de l’interface LoRaWAN
static LoRaWANInterface lorawan(radio);
static lorawan_app_callbacks_t callbacks;
static EventQueue ev_queue;

// Clé de réseau, clé d’application et adresse du dispositif pour ABP
static uint32_t DEVADDR = 0x260B9922; // Remplacez par votre DevAddr
static uint8_t NWKSKEY = { 0x1F, 0x3B, 0x32, 0xB8, 0xFF, 0x04, 0x4A, 0x15, 0xE9, 0x04, 0xE8, 0x94, 0xD3, 0x24, 0x1C, 0x6E }; // Remplacez par votre NwkSKey
static uint8_t APPSKEY = { 0x6A, 0x99, 0xCB, 0x86, 0x6C, 0x99, 0x91, 0x9F, 0x7C, 0xFD, 0xF7, 0x30, 0xC4, 0x77, 0x6D, 0xD9 }; // Remplacez par votre AppSKey

static void lora_event_handler(lorawan_event_t event) {
printf(“Événement LoRa : %d\n”, event);
switch (event) {
case CONNECTED:
printf(“Connexion réussie!\n”);
break;
case DISCONNECTED:
printf(“Déconnexion!\n”);
break;
case TX_DONE:
printf(“Transmission terminée!\n”);
break;
case TX_TIMEOUT:
case TX_ERROR:
case TX_CRYPTO_ERROR:
case TX_SCHEDULING_ERROR:
printf(“Erreur de transmission!\n”);
break;
case RX_DONE:
printf(“Message reçu!\n”);
break;
case RX_TIMEOUT:
case RX_ERROR:
printf(“Erreur de réception!\n”);
break;
case JOIN_FAILURE:
printf(“Échec de la connexion!\n”);
break;
case UPLINK_REQUIRED:
printf(“Uplink requis!\n”);
break;
default:
printf(“Événement inconnu (%d)!\n”, event);
break;
}
}

void send_message() {
uint8_t tx_buffer = “hello ttn”;
int16_t retcode = lorawan.send(15, tx_buffer, sizeof(tx_buffer), MSG_UNCONFIRMED_FLAG);
printf(“Envoi d’un message…\n”);
if (retcode < 0) {
printf(“Échec de l’envoi du message (%d)!\n”, retcode);
} else {
printf(“Message envoyé!\n”);
}
}

int main() {
// Initialisation de la trace
setup_trace();
printf(“Trace initialisée…\n”);

// Initialisation de l'interface LoRaWAN
if (lorawan.initialize(&ev_queue) != LORAWAN_STATUS_OK) {
    printf("Échec de l'initialisation de LoRa!\n");
    return -1;
}
printf("Interface LoRaWAN initialisée...\n");

// Configuration des callbacks
callbacks.events = mbed::callback(lora_event_handler);
lorawan.add_app_callbacks(&callbacks);
printf("Callbacks configurés...\n");

// Configuration des paramètres ABP
lorawan_connect_t connection_params;
connection_params.connect_type = LORAWAN_CONNECTION_ABP;
connection_params.connection_u.abp.dev_addr = DEVADDR;
connection_params.connection_u.abp.nwk_skey = NWKSKEY;
connection_params.connection_u.abp.app_skey = APPSKEY;
printf("Paramètres ABP configurés...\n");

// Connexion au réseau
if (lorawan.connect(connection_params) != LORAWAN_STATUS_OK) { 
    printf("Échec de la connexion LoRa!\n");
    return -1;
}
printf("Connexion LoRaWAN en cours...\n");

// Envoi d'un message après connexion
send_message();

// Boucle principale
ev_queue.dispatch_forever();

}

Here are the steps I followed and the issues I am facing:

-. The code compiles successfully without any errors.
-. Upon running the code, I see the following outputs:

  • “Trace initialisée…”
  • “Interface LoRaWAN initialisée…”
  • “Callbacks configurés…”
  • “Paramètres ABP configurés…”
  • “Connexion LoRaWAN en cours…”
    *“Échec de la connexion LoRa!”
  • Consequently, the “Envoi d’un message…” message does not appear, indicating that the send_message function is not being called.

I have verified that my DevAddr, NwkSKey, and AppSKey are correct and match the details provided in TTN. Additionally, I am not seeing any activity on the TTN console.

4

This ^^^

Please consider that you are making it harder for the volunteers to answer.

5

Just to clarify, you have a message that comes up that tells you where in the code that it got to. What have you looked at to investigate this?

6

I compiled the code using the command: mbedtools compile -m LORA_E5_DEV_BOARD -t GCC_ARM
This successfully created a .hex file, which I then downloaded to the board. The messages I observed were displayed in Tera Term when I powered up the board

7

All fine and good - but what have you done about the actual error that you get?

Do you understand the flow of the code?