nRF52 receiving data from 24L01 incorrectly

[Lam]

Hi,

I am using a 24L01+(as PTX) communicating with a nrf52832(as PRX).

I can have these two device communicating, where nrf52832 can receive data from 24L01+.

However, the data nrf52832 received is not the exactly same as the data 24L01+ has transmitted. For example, the 24L01+ is transmitting a 3-byte data(e.g. 0x123456) to nRF52832, while the data nRF52832 received is 0x2468AC. As you can see, 0x2468AC = 0x123456 <- 1. However, in another test, the 24L01+ transmitted 0x676767, while the nRF52832 received 0xCECECF.

Any suggestion would be appreciated. 

Best regards!

[Håkon Alseth]

Hi,

 

It sounds like you have configured the radio incorrectly, especially the endianess of the nrf52 radio (see PCNF1 register)

Have you tried using nrf_esb library for nRF52 to see if that works better?

 

Kind regards,

Håkon

[Lam]

Thanks for your suggestion.

The program running on the nRF52832 was modified from the nRF52 SDK 15.0.0 esb_prx example. It uses the nrf_esb library to recieve data.

A part of my code which config the esb is as follows.

uint32_t esb_init( void )
{
    uint32_t err_code;
    uint8_t base_addr_0[3] = {0xE7, 0xE7, 0xE7};
    uint8_t base_addr_1[3] = {0xC2, 0xC2, 0xC2};
    uint8_t addr_prefix[2] = {0xE7, 0xC2};
    nrf_esb_config_t nrf_esb_config         = NRF_ESB_LEGACY_CONFIG;
    nrf_esb_config.payload_length           = 3;
    nrf_esb_config.crc 	                	= NRF_ESB_CRC_8BIT;
    nrf_esb_config.protocol                 = NRF_ESB_PROTOCOL_ESB;
    nrf_esb_config.bitrate                  = NRF_ESB_BITRATE_2MBPS;
    nrf_esb_config.mode                     = NRF_ESB_MODE_PRX;
    nrf_esb_config.event_handler            = nrf_esb_event_handler;
    nrf_esb_config.selective_auto_ack       = false;

    err_code = nrf_esb_init(&nrf_esb_config);
    VERIFY_SUCCESS(err_code);		
		
    err_code = nrf_esb_set_rf_channel(73);
    VERIFY_SUCCESS(err_code);
		
    err_code = nrf_esb_set_address_length(4);
    VERIFY_SUCCESS(err_code);

    err_code = nrf_esb_set_base_address_0(base_addr_0);
    VERIFY_SUCCESS(err_code);

    err_code = nrf_esb_set_base_address_1(base_addr_1);
    VERIFY_SUCCESS(err_code);

    err_code = nrf_esb_set_prefixes(addr_prefix, 2);
    VERIFY_SUCCESS(err_code);

    return err_code;
}

I don't know where I should modify my code. 

Thanks

[Håkon Alseth]

That is strange. Looking at the bit stream, it seems that your data is shifted one bit (0x676767 << 1 becomes 0xCECECF).

Do you have several nRF24L01+ modules, and they all behave like this? Do you have a link to where you obtained them?

 

Kind regards,

Håkon

[Lam]

I have several 24L01+ modules and they can work well with each other. Also I have several nRF52832 modules and they work well too.

Since 24L01+ can receive data correctly from 24L01+, the 24L01+ may not have problem and so does nRF52832. It is so strange.

[Håkon Alseth]

Are you sending ESB-packets from the nRF24L01+, or are you using the older "shockburst" packet format?

Could you post the nRF24L01+ configuration that you are using? A register dump would suffice.

 

Cheers,

Håkon

[Lam]

void TX_Mode(void)
{														 
    

  	SPI1_Write_Buf(SPI_WRITE_REG+TX_ADDR,(uint8_t*)TX_ADDRESS,TX_ADR_WIDTH);    
	  
  	SPI1_Write_REG(SPI_WRITE_REG+EN_AA,0x00);    

  	SPI1_Write_REG(SPI_WRITE_REG+EN_RXADDR,0x00); //0x01  //close--0x00

  	SPI1_Write_REG(SPI_WRITE_REG+SETUP_RETR,0x00);//0x1a  //close--0x00

  	SPI1_Write_REG(SPI_WRITE_REG+RF_CH,0x49);     //频率，0x00~0x4e    

  	SPI1_Write_REG(SPI_WRITE_REG+RF_SETUP,0x08);  //0x26  ---- 250k    //0x0f ----2M   //0x06 ----1M   //B1000-0x08  -18db    //B1110-0x0f  0db 

  	SPI1_Write_REG(SPI_WRITE_REG+CONFIG,0x0a);    //0x0e--16crc    //0x0a--8crc
        
	CE_H;                                  
}	

24L01+ using Shorkburst but not ESB? How do I know what protocol it is using? As far as I know, it uses ESB as default?

Thanks

[Håkon Alseth]

Hi,

 

You're using ShockBurst, as you are disabling EN_AA and setting field ARC in register SETUP_RETR to '0'. This will effectively omit the 9 bit "PCF" field from the on-air RF payload, as explained in the nrf24l01+ datasheet in chapter 7.9. The nRF52 library nrf_esb expects to receive in ESB mode, not SB mode.

The nrf_esb library does not support the legacy "shockburst" mode, unfortunately.

 

Kind regards,

Håkon

[cama]

Hi. Thank you for reply.

Same confing as LamGELI. Now I enable EN_AA, and ARC is set to 5. As recommanded.

I allways get CRC mismatch (CRCSTATUS=0). While nRF24 in ShockBurst mode make right CRC for nRF52 side, but false payload (one bit shifted). I notice that every received radio event, have payload first byte to 0x00 (payload size). Then I enable dynamic payload too, at nRF24 side : Same result.

Otherwise, I try to make ShockBurst on nRF52 side with S0LEN=0 and S1LEN=0 : same result, CRC errors.

Maybe LamGELI will have more luck.

[cama]

LamGELI, if you're still interested, I found the right nRF52 config for your original nRF24 setup.

You must set registers as : LFLEN=0; S0LEN=0; S1LEN=0; BALEN=4; MAXLEN=payload_size; STATLEN=payload_size.

For this, you could modify update_rf_payload_format_esb function on nrf_esb.c SDK.

With this config, CRC check if good, and you receive right data on payload buffer.