What are the reception parameters of the nucleo LoRa applications/examples ?

[D.Heink]

Hi,

Context:

I am currently developing a LoRa board implementing the STM32WL55. I didn't get the SubGHz Middleware to work, so i implemented the approach as detailed in the reference manual page 206.

The code compiles, and the tx-complete interrupt is getting triggered, so everything seems to work as it should.

I then tried to receive my LoRa messages with a Nucleo Board, where i modified the SubGHz_Phy_PingPong example to not send Pings anymore and print everything it recieves to the USB UART. It works perfectly when I send lora data via another Nucleo.

I saw that in the subghz_phy_app.h of the PingPong Example it says:

#define LORA_BANDWIDTH                              0         /* [0: 125 kHz, 1: 250 kHz, 2: 500 kHz, 3: Reserved] */
#define LORA_SPREADING_FACTOR                       7       /* [SF7..SF12] */
#define LORA_CODINGRATE                             1         /* [1: 4/5, 2: 4/6, 3: 4/7, 4: 4/8] */
#define LORA_PREAMBLE_LENGTH                        8         /* Same for Tx and Rx */
#define LORA_SYMBOL_TIMEOUT                         64         /* Symbols */
#define LORA_FIX_LENGTH_PAYLOAD_ON                  false
#define LORA_IQ_INVERSION_ON                        false

And adjusted my settings accordingly,but the nucleo doesn't receive the lora messages from my custom board.

Question :

What are the receive parameters of the nucleo-WL55JCI7 Board Examples?

My seding code is:

//Wakeup and check for standby mode 
if (HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_SET_SLEEP, &RadioParam, 1) != HAL_OK)
  {
    Error_Handler();
  }
 
  /* Set Standby Mode */
  if (HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_SET_STANDBY, &RadioParam, 1) != HAL_OK)
  {
    Error_Handler();
  }
 
  /* Retrieve Status from SUBGHZ Radio */
  if (HAL_SUBGHZ_ExecGetCmd(&hsubghz, RADIO_GET_STATUS, &RadioResult, 1) != HAL_OK)
  {
    Error_Handler();
  }
  else
  {
    /* Format Mode and Status receive from SUBGHZ Radio */
    RadioMode   = ((RadioResult & RADIO_MODE_BITFIELD) >> 4);
 
    /* Check if SUBGHZ Radio is in RADIO_MODE_STANDBY_RC mode */
    if(RadioMode != RADIO_MODE_STANDBY_RC)
    {
      Error_Handler();
    }
  }
 
 
 //1. set Buffer base Address
  buf[0]  = 0x80; 	//TX base address
  buf[1]= 0x00;	   	//RX base address
  if(HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_SET_BUFFERBASEADDRESS, buf,2 )!= HAL_OK ){ Error_Handler();}
 
 
  //2. Fill buffer with test message
if(HAL_SUBGHZ_WriteBuffer(&hsubghz, 0x80, testMessage, 5) != HAL_OK){Error_Handler();}
 
 
//3. Set packet type (LoRa)
buf[0]= 0b00000001; //LoRa
if(HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_SET_PACKETTYPE, buf, 1)){Error_Handler();}
 
 
//4. Define format
buf[0]= 0; 	// Preamble length lsb
buf[1]= 12;	//preamble lenght rsb
buf[2]= 0;	//explicit header for varibale payload length
buf[3]= 5;	// Payload lenght in byte
buf[4]= 1; 	//CRC Enabled
buf[5]= 0;  //standard IQ setup
if(HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_SET_PACKETPARAMS , buf, 6)!= HAL_OK){Error_Handler();}
 
 
//5. Syncword, didnt find anything in the documentation i think it is only necessary for non Lora transmission
 
//6. Set Frequency
buf[0]= 0b00100011;
buf[1]= 0b01110110;
buf[2]= 0b10010011;
buf[3]= 0b01111100;// set to 594973564
if(HAL_SUBGHZ_ExecSetCmd(&hsubghz,RADIO_SET_RFFREQUENCY , buf, 4)){Error_Handler();}
 
 
//7. Setup PA
buf[0]= 0x2;  	//set dutycycle
buf[1]= 0x2;	//set output power to 14dBm
buf[2]= 0;		//set HP PA
buf[3]= 0x01; 	//random stuff that the doc wants
if(HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_SET_PACONFIG, buf, 4 )!=HAL_OK){Error_Handler();}
 
//8. Define PA output power and rampup
buf[0]= 0x16; //set power according to table 35 in the Reference manual
buf[1]= 0x02; //set rampup time to 40us
if(HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_SET_TXPARAMS, buf, 2)!=HAL_OK){Error_Handler();}
 
 
//9. define the modulation params
buf[0]= 0x7; 	//Spreading factor 7
buf[1]= 0x04;	//bandwidth 125kHz
buf[2]= 0x1;	//Cr 4/5
buf[3]= 0;		//No Low data rate optimization
if(HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_SET_MODULATIONPARAMS, buf, 4)){Error_Handler();}
 
 
//10. Enable Interrupts
buf[0]= 0b00000010;// enable Txdone
buf[1]= 1; // enable timeout
buf[2]= 0b00000010;
buf[3]=1;
buf[4]= 0;
buf[5]= 0;
buf[6]= 0;
buf[7]= 0;// enable both on irq1 line
if(HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_CFG_DIOIRQ, buf, 8)){Error_Handler();}
 
 
//set HF switch
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_7, GPIO_PIN_SET);
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_6, GPIO_PIN_RESET);
 
//11. start transmission
buf[0]= 0;
buf[1]= 0b01111101;
buf[2]= 0b00000000; //set timeout to 500ms
if(HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_SET_TX, buf, 3)){Error_Handler();}
 
 
 
 
//12. wait for interrupt
 
uint8_t temp = 0;
while (!temp){
	temp = Radio_Interrupt_Happened;
 
}
 
//13. clear Interrupt done by interrupt handler

[Tesla DeLorean]

Debugging radio is something you can bury hours/days into.

Not sure there's a lot of interest here getting into bit level register fiddling.

You have the sources, get some decent static analysis tools and mine into it. Read back registers in working / non-working cases. Write code to unpack and decode them in a human readable fashion.

[JPablo1]

Did you find out the parameters of the receiving board?

In addition, in which line do you send the 'test message'?