STM32WLE5, LoRaWAN ABP example , Initialise radio failed

[keniihuang99]

Hi Sir,
I am trying STM32WLE5:
for STM32WLx_Transmit_Blocking example, it work well.

for LoRaWAN_ABP example , there is error message as:
Setup ...
Initialise the radio
[2.000004] RLB_DBG: GPIO pre-transfer timeout, is it connected?
[3.029003] RLB_DBG: GPIO pre-transfer timeout, is it connected?
[3.061704] RLB_DBG:
RadioLib Info
Version: "7.2.1.0"
Platform: "Arduino STM32 (official)"
"Dec 13 2025" "16:22:59"
[3.191815] RLB_DBG: Found SX126x: RADIOLIB_SX126X_REG_VERSION_STRING:
[3.254901] RLB_DBG: 00000320: 53 58 31 32 36 31 20 54 4b 46 20 31 41 31 30 00 SX1261 TKF 1A10.
[3.384774] RLB_DBG:
[3.384839] RLB_DBG: M SX126x
Initialise radio failed - See https://jgromes.github.io/RadioLib/group__status__codes.html (-707)

================================================================

Hardware is the same, and need help to figure out the problem. Code is as:
#include "configABP.h"

void setup() {
Serial.begin(9600);
while(!Serial) delay(10);
delay(1000); // Give time to switch to the serial monitor
Serial.println(F("\nSetup ... "));

Serial.println(F("Initialise the radio"));
// set RF switch control configuration
// this has to be done prior to calling begin()
radio.setRfSwitchTable(rfswitch_pins, rfswitch_table);

radio.setTCXO(false);
int state = radio.begin();

debug(state != RADIOLIB_ERR_NONE, F("Initialise radio failed"), state, true);
Serial.println(F("Initialise LoRaWAN Network credentials"));
node.beginABP(devAddr, fNwkSIntKey, sNwkSIntKey, nwkSEncKey, appSKey);

node.activateABP();
debug(state != RADIOLIB_ERR_NONE, F("Activate ABP failed"), state, true);

Serial.println(F("Ready!\n"));

}

void loop() {
Serial.println(F("Sending uplink"));

// This is the place to gather the sensor inputs
// Instead of reading any real sensor, we just generate some random numbers as example
uint8_t value1 = radio.random(100);
uint16_t value2 = radio.random(2000);

// Build payload byte array
uint8_t uplinkPayload[3];
uplinkPayload[0] = value1;
uplinkPayload[1] = highByte(value2); // See notes for high/lowByte functions
uplinkPayload[2] = lowByte(value2);

// Perform an uplink
int state = node.sendReceive(uplinkPayload, sizeof(uplinkPayload));
debug(state < RADIOLIB_ERR_NONE, F("Error in sendReceive"), state, false);

// Check if a downlink was received
// (state 0 = no downlink, state 1/2 = downlink in window Rx1/Rx2)
if(state > 0) {
Serial.println(F("Received a downlink"));
} else {
Serial.println(F("No downlink received"));
}

Serial.print(F("Next uplink in "));
Serial.print(uplinkIntervalSeconds);
Serial.println(F(" seconds\n"));

// Wait until next uplink - observing legal & TTN FUP constraints
delay(uplinkIntervalSeconds * 1000UL); // delay needs milli-seconds

}

====================================================================

configABP.h is as:
#ifndef _RADIOLIB_EX_LORAWAN_CONFIG_H
#define _RADIOLIB_EX_LORAWAN_CONFIG_H

#include <RadioLib.h>
//#include <stdlib.h>
//HardwareSerial Serial1(PB7, PB6);

// no need to configure pins, signals are routed to the radio internally
STM32WLx radio = new STM32WLx_Module();

static const uint32_t rfswitch_pins[] =
{PB8, PC13, RADIOLIB_NC, RADIOLIB_NC, RADIOLIB_NC};
static const Module::RfSwitchMode_t rfswitch_table[] = {
{STM32WLx::MODE_IDLE, {LOW, LOW}},
{STM32WLx::MODE_RX, {HIGH, LOW}},
{STM32WLx::MODE_TX_LP, {HIGH, HIGH}},
{STM32WLx::MODE_TX_HP, {LOW, HIGH}},
END_OF_MODE_TABLE,
};

// if you have RadioBoards (https://github.com/radiolib-org/RadioBoards)
// and are using one of the supported boards, you can do the following:
/*
#define RADIO_BOARD_AUTO
#include <RadioBoards.h>

Radio radio = new RadioModule();
*/

// how often to send an uplink - consider legal & FUP constraints - see notes
const uint32_t uplinkIntervalSeconds = 1UL * 60UL; // minutes x seconds

// device address - either a development address or one assigned
// to the LoRaWAN Service Provider - TTN will generate one for you
#ifndef RADIOLIB_LORAWAN_DEV_ADDR // Replace with your DevAddr
#define RADIOLIB_LORAWAN_DEV_ADDR 0xaa345678
#endif

#ifndef RADIOLIB_LORAWAN_FNWKSINT_KEY // Replace with your FNwkSInt Key
//11 7e 15 16 28 ae d2 a6 ab f7 15 88 09 cf 4f 3d
#define RADIOLIB_LORAWAN_FNWKSINT_KEY 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3d
#endif
#ifndef RADIOLIB_LORAWAN_SNWKSINT_KEY // Replace with your SNwkSInt Key
#define RADIOLIB_LORAWAN_SNWKSINT_KEY 0x11, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3d
#endif
#ifndef RADIOLIB_LORAWAN_NWKSENC_KEY // Replace with your NwkSEnc Key
#define RADIOLIB_LORAWAN_NWKSENC_KEY 0x11, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3d
#endif
#ifndef RADIOLIB_LORAWAN_APPS_KEY // Replace with your AppS Key
#define RADIOLIB_LORAWAN_APPS_KEY 0x11, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3d
#endif

// for the curious, the #ifndef blocks allow for automated testing &/or you can
// put your EUI & keys in to your platformio.ini - see wiki for more tips

// regional choices: EU868, US915, AU915, AS923, AS923_2, AS923_3, AS923_4, IN865, KR920, CN470
const LoRaWANBand_t Region = AS923;

// subband choice: for US915/AU915 set to 2, for CN470 set to 1, otherwise leave on 0
const uint8_t subBand = 0;

// ============================================================================
// Below is to support the sketch - only make changes if the notes say so ...

// copy over the keys in to the something that will not compile if incorrectly formatted
uint32_t devAddr = RADIOLIB_LORAWAN_DEV_ADDR;
uint8_t fNwkSIntKey[] = { RADIOLIB_LORAWAN_FNWKSINT_KEY };
uint8_t sNwkSIntKey[] = { RADIOLIB_LORAWAN_SNWKSINT_KEY };
uint8_t nwkSEncKey[] = { RADIOLIB_LORAWAN_NWKSENC_KEY };
uint8_t appSKey[] = { RADIOLIB_LORAWAN_APPS_KEY };

// create the LoRaWAN node
LoRaWANNode node(&radio, &Region, subBand);

// result code to text - these are error codes that can be raised when using LoRaWAN
// however, RadioLib has many more - see https://jgromes.github.io/RadioLib/group__status__codes.html for a complete list
String stateDecode(const int16_t result) {
switch (result) {
case RADIOLIB_ERR_NONE:
return "ERR_NONE";
case RADIOLIB_ERR_CHIP_NOT_FOUND:
return "ERR_CHIP_NOT_FOUND";
case RADIOLIB_ERR_PACKET_TOO_LONG:
return "ERR_PACKET_TOO_LONG";
case RADIOLIB_ERR_RX_TIMEOUT:
return "ERR_RX_TIMEOUT";
case RADIOLIB_ERR_MIC_MISMATCH:
return "ERR_MIC_MISMATCH";
case RADIOLIB_ERR_INVALID_BANDWIDTH:
return "ERR_INVALID_BANDWIDTH";
case RADIOLIB_ERR_INVALID_SPREADING_FACTOR:
return "ERR_INVALID_SPREADING_FACTOR";
case RADIOLIB_ERR_INVALID_CODING_RATE:
return "ERR_INVALID_CODING_RATE";
case RADIOLIB_ERR_INVALID_FREQUENCY:
return "ERR_INVALID_FREQUENCY";
case RADIOLIB_ERR_INVALID_OUTPUT_POWER:
return "ERR_INVALID_OUTPUT_POWER";
case RADIOLIB_ERR_NETWORK_NOT_JOINED:
return "RADIOLIB_ERR_NETWORK_NOT_JOINED";
case RADIOLIB_ERR_DOWNLINK_MALFORMED:
return "RADIOLIB_ERR_DOWNLINK_MALFORMED";
case RADIOLIB_ERR_INVALID_REVISION:
return "RADIOLIB_ERR_INVALID_REVISION";
case RADIOLIB_ERR_INVALID_PORT:
return "RADIOLIB_ERR_INVALID_PORT";
case RADIOLIB_ERR_NO_RX_WINDOW:
return "RADIOLIB_ERR_NO_RX_WINDOW";
case RADIOLIB_ERR_INVALID_CID:
return "RADIOLIB_ERR_INVALID_CID";
case RADIOLIB_ERR_UPLINK_UNAVAILABLE:
return "RADIOLIB_ERR_UPLINK_UNAVAILABLE";
case RADIOLIB_ERR_COMMAND_QUEUE_FULL:
return "RADIOLIB_ERR_COMMAND_QUEUE_FULL";
case RADIOLIB_ERR_COMMAND_QUEUE_ITEM_NOT_FOUND:
return "RADIOLIB_ERR_COMMAND_QUEUE_ITEM_NOT_FOUND";
case RADIOLIB_ERR_JOIN_NONCE_INVALID:
return "RADIOLIB_ERR_JOIN_NONCE_INVALID";
case RADIOLIB_ERR_DWELL_TIME_EXCEEDED:
return "RADIOLIB_ERR_DWELL_TIME_EXCEEDED";
case RADIOLIB_ERR_CHECKSUM_MISMATCH:
return "RADIOLIB_ERR_CHECKSUM_MISMATCH";
case RADIOLIB_ERR_NO_JOIN_ACCEPT:
return "RADIOLIB_ERR_NO_JOIN_ACCEPT";
case RADIOLIB_LORAWAN_SESSION_RESTORED:
return "RADIOLIB_LORAWAN_SESSION_RESTORED";
case RADIOLIB_LORAWAN_NEW_SESSION:
return "RADIOLIB_LORAWAN_NEW_SESSION";
case RADIOLIB_ERR_NONCES_DISCARDED:
return "RADIOLIB_ERR_NONCES_DISCARDED";
case RADIOLIB_ERR_SESSION_DISCARDED:
return "RADIOLIB_ERR_SESSION_DISCARDED";
}
return "See https://jgromes.github.io/RadioLib/group__status__codes.html";
}

// helper function to display any issues
void debug(bool failed, const __FlashStringHelper* message, int state, bool halt) {
if(failed) {
Serial.print(message);
Serial.print(" - ");
Serial.print(stateDecode(state));
Serial.print(" (");
Serial.print(state);
Serial.println(")");
while(halt) { delay(1); }
}
}

// helper function to display a byte array
void arrayDump(uint8_t *buffer, uint16_t len) {
for(uint16_t c = 0; c < len; c++) {
char b = buffer[c];
if(b < 0x10) {
Serial.println('0');
}
Serial.print(b, HEX);
}
Serial.println();
}

#endif

[jgromes]

Initialise radio failed - See https://jgromes.github.io/RadioLib/group__status__codes.html (-707)

I would suggest following that link, and finding the error message in question. In there, you will find an explanation as to what is going on. We even have a dedicated Troubleshooting guide on our wiki.

To fix your problem, you have to get rid of this:

radio.setTCXO(false);
int state = radio.begin();

You cannot call radio.setTCXO before teh radio has been initialized. The correct way to do this is shown in the resources linked above.

[keniihuang99]

Hi Jgromes,

Thanks for your commend.

After modify code to be:
Serial.println(F("Initialise the radio"));
int state = radio.begin(923.2, 125.0, 10, 5, RADIOLIB_SX126X_SYNC_WORD_PUBLIC, 22, 8, 0);
debug(state != RADIOLIB_ERR_NONE, F("Initialise radio failed"), state, true);

it work well now.

Thanks again!