Using Spreading factor 12 on NUCLEO-WL55JC1 LoRa boards

[JMala.3]

I have 2 NUCLEO-WL55JC1 boards I am using to communicate using LoRa.  The Tx board sends a message every 10 seconds, the Rx board receives the message and lights up an LED..I have this working at SF7, the same spreading factor as the ping-pong example I copied the code from, but if I try to change this to SF12 (on both Tx and Rx projects) the Rx board never receives messages.

Any ideas on how I can fix this?  Her is the code

 

#include <stdio.h>
#include <radio_driver.h>
#include "types.h"
#include "radio.h"

#define RF_FREQUENCY 924000000 /* Hz */
#define TX_OUTPUT_POWER 14 /* dBm */
#define LORA_BANDWIDTH LORA_BW_500 /* KHz */
#define LORA_SPREADING_FACTOR LORA_SF9
#define LORA_CODINGRATE LORA_CR_4_5
#define LORA_PREAMBLE_LENGTH 8 /* Same for Tx and Rx */
#define LORA_SYMBOL_TIMEOUT 5 /* Symbols */
 
#define LORA_RX_TIMEOUT 10000 /* milliseconds */
#define RADIO_RX_BUFFER_SIZE 10
#define ZERO_OFFSET 0

typedef enum {
 RADIO_STATE_IDLE,
 RADIO_STATE_RX_COMPLETE,
 RADIO_STATE_RX_ERROR
} RADIO_STATES;

PacketParams_t Radio_PacketParams;
const RadioLoRaBandwidths_t Radio_Bandwidths[] = { LORA_BW_125, LORA_BW_250, LORA_BW_500 };
RADIO_STATES Radio_State;

const char Radio_TimeoutText[] = "Rx Timeout\r\n";
const char Radio_ReceivedText[] = "Rx Received\r\n";
const char Radio_InitializedText[] = "Radio Initialized\r\n";
const char Radio_CrlfText[] = "\r\n";
extern UART_HandleTypeDef huart2;

void Radio_ReceiveMsg( void );
void Radio_IrqHandler(RadioIrqMasks_t radioIrq);

/*****************************************************************************************
 * FUNCTION:	Radio_Init
 * 
 * DESCRIPTION:	Initializes LoRa Radio
 *
 * PARAMETERS: None
 *
 * RETURN: 		None
 *****************************************************************************************/
void Radio_Init(void)
{
 ModulationParams_t modulationParams;
 
 // Initialize the hardware (SPI bus, TCXO control, RF switch)
 SUBGRF_Init(Radio_IrqHandler);

 // Use DCDC converter if `DCDC_ENABLE` is defined in radio_conf.h
 // "By default, the SMPS clock detection is disabled and must be enabled before enabling the SMPS." (6.1 in RM0453)
 SUBGRF_WriteRegister(SUBGHZ_SMPSC0R, (SUBGRF_ReadRegister(SUBGHZ_SMPSC0R) | SMPS_CLK_DET_ENABLE));
 SUBGRF_SetRegulatorMode();

 // Use the whole 256-byte buffer for both TX and RX
 SUBGRF_SetBufferBaseAddress(0x00, 0x00);

 SUBGRF_SetRfFrequency(RF_FREQUENCY);
 SUBGRF_SetRfTxPower(TX_OUTPUT_POWER);
 SUBGRF_SetStopRxTimerOnPreambleDetect(FALSE);

 SUBGRF_SetPacketType(PACKET_TYPE_LORA);

 SUBGRF_WriteRegister( REG_LR_SYNCWORD, ( LORA_MAC_PRIVATE_SYNCWORD >> 8 ) & 0xFF );
 SUBGRF_WriteRegister( REG_LR_SYNCWORD + 1, LORA_MAC_PRIVATE_SYNCWORD & 0xFF );

 modulationParams.PacketType = PACKET_TYPE_LORA;
 modulationParams.Params.LoRa.Bandwidth = LORA_BANDWIDTH;
 modulationParams.Params.LoRa.CodingRate = LORA_CODINGRATE;
 modulationParams.Params.LoRa.LowDatarateOptimize = 0x00;
 modulationParams.Params.LoRa.SpreadingFactor = LORA_SPREADING_FACTOR;
 SUBGRF_SetModulationParams(&modulationParams);

 Radio_PacketParams.PacketType = PACKET_TYPE_LORA;
 Radio_PacketParams.Params.LoRa.CrcMode = LORA_CRC_ON;
 Radio_PacketParams.Params.LoRa.HeaderType = LORA_PACKET_VARIABLE_LENGTH;
 Radio_PacketParams.Params.LoRa.InvertIQ = LORA_IQ_NORMAL;
 Radio_PacketParams.Params.LoRa.PayloadLength = 0xFF;
 Radio_PacketParams.Params.LoRa.PreambleLength = LORA_PREAMBLE_LENGTH;
 SUBGRF_SetPacketParams(&Radio_PacketParams);

 //SUBGRF_SetLoRaSymbNumTimeout(LORA_SYMBOL_TIMEOUT);

 // WORKAROUND - Optimizing the Inverted IQ Operation, see DS_SX1261-2_V1.2 datasheet chapter 15.4
 // RegIqPolaritySetup @address 0x0736
 SUBGRF_WriteRegister( 0x0736, SUBGRF_ReadRegister( 0x0736 ) | ( 1 << 2 ) );
 
	HAL_UART_Transmit(&huart2, (uint8_t *)Radio_InitializedText, sizeof(Radio_InitializedText) - 1, HAL_MAX_DELAY);
 BSP_LED_On(LED_GREEN);
 Radio_State = RADIO_STATE_IDLE;
 Radio_ReceiveMsg();
}

/*****************************************************************************************
 * FUNCTION:	Radio_IrqHandler
 * 
 * DESCRIPTION:	Process a radio interrupt
 *
 * PARAMETERS: radioIrq - Event causing the interrupt
 *
 * RETURN: 		None
 *****************************************************************************************/
void Radio_IrqHandler(RadioIrqMasks_t radioIrq)
{
 switch (radioIrq)
 {
 case IRQ_TX_DONE:
 break;
 case IRQ_RX_DONE:
 Radio_State = RADIO_STATE_RX_COMPLETE; 
 break;
 case IRQ_RX_TX_TIMEOUT:
 Radio_State = RADIO_STATE_RX_ERROR; 
 break;
 case IRQ_CRC_ERROR:
 Radio_State = RADIO_STATE_RX_ERROR; 
 break;
 default:
 Radio_State = RADIO_STATE_IDLE; 
 break;
 }
}

/*****************************************************************************************
 * FUNCTION:	Radio_HandleTick
 * 
 * DESCRIPTION:	Process a Lora radio interrupt
 *
 * PARAMETERS: radioIrq - Event causing the interrupt
 *
 * RETURN: 		None
 *****************************************************************************************/
void Radio_HandleTick(void)
{
 char RxBuffer[RADIO_RX_BUFFER_SIZE];

 if(Radio_State != RADIO_STATE_IDLE)
 {
 if(Radio_State == RADIO_STATE_RX_COMPLETE)
 {
 memset(RxBuffer, 0 , sizeof(RxBuffer));
 SUBGRF_ReadBuffer( ZERO_OFFSET, (uint8_t *)RxBuffer, RADIO_RX_BUFFER_SIZE );
 strcat(RxBuffer, Radio_CrlfText);
 HAL_UART_Transmit(&huart2, (uint8_t *)RxBuffer, RADIO_RX_BUFFER_SIZE, HAL_MAX_DELAY);
 BSP_LED_On(LED_RED);
 HAL_Delay(500);
 BSP_LED_Off(LED_RED);
 }
 else if(Radio_State == RADIO_STATE_RX_ERROR)
 {
 HAL_UART_Transmit(&huart2, (uint8_t *)Radio_TimeoutText, sizeof(Radio_TimeoutText) - 1, HAL_MAX_DELAY);
 }
 Radio_ReceiveMsg();
 	Radio_State = RADIO_STATE_IDLE;
 }
}

/*****************************************************************************************
 * FUNCTION:	Radio_ReceiveMsg
 * 
 * DESCRIPTION:	Receive a message from the Roam Remote
 *
 * PARAMETERS: None
 *
 * RETURN: 		None
 *****************************************************************************************/
void Radio_ReceiveMsg( void )
{
 SUBGRF_SetDioIrqParams( IRQ_RX_DONE | IRQ_RX_TX_TIMEOUT | IRQ_CRC_ERROR | IRQ_HEADER_ERROR,
 IRQ_RX_DONE | IRQ_RX_TX_TIMEOUT | IRQ_CRC_ERROR | IRQ_HEADER_ERROR,
 IRQ_RADIO_NONE,
 IRQ_RADIO_NONE );
 
 SUBGRF_SetSwitch(RFO_LP, RFSWITCH_RX);
 
 Radio_PacketParams.Params.LoRa.PayloadLength = 0xFF;
 SUBGRF_SetPacketParams(&Radio_PacketParams);
 
 SUBGRF_SetRx(LORA_RX_TIMEOUT << 6);
}

 

 

 

[Tesla DeLorean]

You don't show the Tx side, but going to need 

void SUBGRF_SetTx( uint32_t timeout );

Probably going to want continuous reception so the Rx side doesn't die mid transaction.

 

[JMala.3]

Thanks for the reply TeslaDelorean Here is the Tx code.  Does this look OK?

I am not using SUBGRF_SetTx.  Can you recommend a value for the timeout?

#include <stdio.h>
#include <radio_driver.h>
#include "types.h"
#include "radio.h"

#define RF_FREQUENCY 924000000 /* Hz */
#define TX_OUTPUT_POWER 14 /* dBm */
#define LORA_BANDWIDTH LORA_BW_500 /* KHz */
#define LORA_SPREADING_FACTOR LORA_SF9
#define LORA_CODINGRATE LORA_CR_4_5
#define LORA_PREAMBLE_LENGTH 8 /* Same for Tx and Rx */
#define LORA_SYMBOL_TIMEOUT 5 /* Symbols */
 
#define LORA_RX_TIMEOUT 10000 /* milliseconds */
#define RADIO_RX_BUFFER_SIZE 10
#define ZERO_OFFSET 0

typedef enum {
 RADIO_STATE_IDLE,
 RADIO_STATE_TX_COMPLETE,
 RADIO_STATE_TX_ERROR
} RADIO_STATES;

PacketParams_t Radio_PacketParams;
const RadioLoRaBandwidths_t Radio_Bandwidths[] = { LORA_BW_125, LORA_BW_250, LORA_BW_500 };
RADIO_STATES Radio_State;
const char Radio_ErrorText[] = "Tx Error\r\n";
const char Radio_TxCompleteText[] = "Tx Complete\r\n";
const char Radio_InitializedText[] = "Radio Initialized\r\n";
const char Radio_PingMsg[] = "Ping";
extern UART_HandleTypeDef huart2;

void Radio_SendMsg( UINT8 *Msg, UINT8 MsgLen );
void Radio_IrqHandler(RadioIrqMasks_t radioIrq);

/*****************************************************************************************
 * FUNCTION:	Radio_Init
 * 
 * DESCRIPTION:	Open UDP socket to simulate messages to the ICC2 simulator
 *
 * PARAMETERS: None
 *
 * RETURN: 		None
 *****************************************************************************************/
void Radio_Init(void)
{
 ModulationParams_t modulationParams;
 
 // Initialize the hardware (SPI bus, TCXO control, RF switch)
 SUBGRF_Init(Radio_IrqHandler);

 // Use DCDC converter if `DCDC_ENABLE` is defined in radio_conf.h
 // "By default, the SMPS clock detection is disabled and must be enabled before enabling the SMPS." (6.1 in RM0453)
 SUBGRF_WriteRegister(SUBGHZ_SMPSC0R, (SUBGRF_ReadRegister(SUBGHZ_SMPSC0R) | SMPS_CLK_DET_ENABLE));
 SUBGRF_SetRegulatorMode();

 // Use the whole 256-byte buffer for both TX and RX
 SUBGRF_SetBufferBaseAddress(0x00, 0x00);

 SUBGRF_SetRfFrequency(RF_FREQUENCY);
 SUBGRF_SetRfTxPower(TX_OUTPUT_POWER);
 SUBGRF_SetStopRxTimerOnPreambleDetect(FALSE);

 SUBGRF_SetPacketType(PACKET_TYPE_LORA);

 SUBGRF_WriteRegister( REG_LR_SYNCWORD, ( LORA_MAC_PRIVATE_SYNCWORD >> 8 ) & 0xFF );
 SUBGRF_WriteRegister( REG_LR_SYNCWORD + 1, LORA_MAC_PRIVATE_SYNCWORD & 0xFF );

 modulationParams.PacketType = PACKET_TYPE_LORA;
 modulationParams.Params.LoRa.Bandwidth = LORA_BANDWIDTH;
 modulationParams.Params.LoRa.CodingRate = LORA_CODINGRATE;
 modulationParams.Params.LoRa.LowDatarateOptimize = 0x00;
 modulationParams.Params.LoRa.SpreadingFactor = LORA_SPREADING_FACTOR;
 SUBGRF_SetModulationParams(&modulationParams);

 Radio_PacketParams.PacketType = PACKET_TYPE_LORA;
 Radio_PacketParams.Params.LoRa.CrcMode = LORA_CRC_ON;
 Radio_PacketParams.Params.LoRa.HeaderType = LORA_PACKET_VARIABLE_LENGTH;
 Radio_PacketParams.Params.LoRa.InvertIQ = LORA_IQ_NORMAL;
 Radio_PacketParams.Params.LoRa.PayloadLength = 0xFF;
 Radio_PacketParams.Params.LoRa.PreambleLength = LORA_PREAMBLE_LENGTH;
 SUBGRF_SetPacketParams(&Radio_PacketParams);

 //SUBGRF_SetLoRaSymbNumTimeout(LORA_SYMBOL_TIMEOUT);

 // WORKAROUND - Optimizing the Inverted IQ Operation, see DS_SX1261-2_V1.2 datasheet chapter 15.4
 // RegIqPolaritySetup @address 0x0736
 SUBGRF_WriteRegister( 0x0736, SUBGRF_ReadRegister( 0x0736 ) | ( 1 << 2 ) );

	HAL_UART_Transmit(&huart2, (uint8_t *)Radio_InitializedText, sizeof(Radio_InitializedText) - 1, HAL_MAX_DELAY);
 BSP_LED_On(LED_GREEN);
 Radio_State = RADIO_STATE_IDLE;
 Radio_SendMsg( (UINT8 *)Radio_PingMsg, sizeof(Radio_PingMsg) - 1 );
}

/*****************************************************************************************
 * FUNCTION:	Radio_IrqHandler
 * 
 * DESCRIPTION:	Process a radio interrupt
 *
 * PARAMETERS: radioIrq - Event causing the interrupt
 *
 * RETURN: 		None
 *****************************************************************************************/
void Radio_IrqHandler(RadioIrqMasks_t radioIrq)
{
 switch (radioIrq)
 {
 case IRQ_TX_DONE:
 Radio_State = RADIO_STATE_TX_COMPLETE;
 break;
 case IRQ_RX_DONE:
 break;
 case IRQ_RX_TX_TIMEOUT:
 Radio_State = RADIO_STATE_TX_ERROR;
 break;
 case IRQ_CRC_ERROR:
 break;
 default:
 Radio_State = RADIO_STATE_IDLE; 
 break;
 }
}

/*****************************************************************************************
 * FUNCTION:	Radio_HandleTick
 * 
 * DESCRIPTION:	Process a Lora radio interrupt
 *
 * PARAMETERS: radioIrq - Event causing the interrupt
 *
 * RETURN: 		None
 *****************************************************************************************/
void Radio_HandleTick(void)
{
 if(Radio_State != RADIO_STATE_IDLE)
 {
 if(Radio_State == RADIO_STATE_TX_COMPLETE)
 {
 HAL_UART_Transmit(&huart2, (uint8_t *)Radio_TxCompleteText, sizeof(Radio_TxCompleteText) - 1, HAL_MAX_DELAY);
 HAL_Delay(10000);
 BSP_LED_On(LED_RED);
 HAL_Delay(500);
 Radio_SendMsg( (UINT8 *)Radio_PingMsg, sizeof(Radio_PingMsg) - 1 );
 BSP_LED_Off(LED_RED);
 }
 else if(Radio_State == RADIO_STATE_TX_ERROR)
 {
 HAL_UART_Transmit(&huart2, (uint8_t *)Radio_ErrorText, sizeof(Radio_ErrorText) - 1, HAL_MAX_DELAY);
 }
 	Radio_State = RADIO_STATE_IDLE;
 }
}

/*****************************************************************************************
 * FUNCTION:	Radio_ReceiveMsg
 * 
 * DESCRIPTION:	Receive a message from the Roam Remote
 *
 * PARAMETERS: None
 *
 * RETURN: 		None
 *****************************************************************************************/
void Radio_SendMsg( UINT8 *Msg, UINT8 MsgLen )
{
 SUBGRF_SetDioIrqParams( IRQ_TX_DONE | IRQ_RX_TX_TIMEOUT,
 IRQ_TX_DONE | IRQ_RX_TX_TIMEOUT,
 IRQ_RADIO_NONE,
 IRQ_RADIO_NONE );
 SUBGRF_SetSwitch(RFO_LP, RFSWITCH_TX);
 // Workaround 5.1 in DS.SX1261-2.W.APP (before each packet transmission)
 SUBGRF_WriteRegister(0x0889, (SUBGRF_ReadRegister(0x0889) | 0x04));
 Radio_PacketParams.Params.LoRa.PayloadLength = MsgLen;
 SUBGRF_SetPacketParams(&Radio_PacketParams);

 SUBGRF_SendPayload((uint8_t *)Msg, MsgLen, 0);
}

 

[Tesla DeLorean]

SUBGRF_SetTx(11000); // 10s + 10% margin

I haven't built with this version but the older library with a slow SF12 beacon, would timeout with ST / SEMTECH examples.

Are you getting a TX_TIMEOUT error? 

Do you idle the SUBGRF_SetSwitch() at some point?

[Joe WILLIAMS]

Hello JMala.3

Your post has been reassigned to the online support team for more assistance.

Kind Regards

Joe WILLIAMS

STMicro Support

[Tesla DeLorean]

Please come back when you have an answer, dark-webbing this stuff in internal systems has significantly less reach.

[JMala.3]

I found the issue.in the function Radio_SendMsg the lines

// Workaround 5.1 in DS.SX1261-2.W.APP (before each packet transmission)
 SUBGRF_WriteRegister(0x0889, (SUBGRF_ReadRegister(0x0889) | 0x04));

Are only applicable for bandwidths less then 500kHz, for 500kHz bandwidth, the bit should be left as a zero.  I removed these line from my code and now it works.