Odd behavior in tx radio and rx radio pairs

[radioschmadio]

I am doing some custom work, and have discovered an odd bug, that I can not seem to figure out.

On the tx radio, I am transmitting a BLE ADV packet with the first 3 bytes 0x4225BB. On the receiving radio, I am receiving 0x422503. The receive radio's checksum is correct (per the crc register). The rest of the packet is correct.

I also tried to transmit a BLE ADV packet with first 3 bytes 0xAAAA0E. The receiving radio picked up 0xAA2A02 and again, the checksum is correct (per the crc register). The rest of the packet is correct, it only seems to effect the 2 bytes.

I have verified the memory of each the tx-er and rx-er at receive and transmit time, and it reinforces the above statements.

I am using a NRF52832 to transmit, and and NRF51822 to receive. I am using custom code, not the Nordic stack. I have tried this on multiple devices and the behavior is the same.

Is there something that I am missing?

[ovrebekk]

Hi

Have you tried to use a phone to receive the adv packet, to see if the issue is the same (or if the packet can even be received) ?

If you have an Android phone the nRF Connect app from Nordic allows you to see the raw data from an advertiser.

Are you able to share the code you used to transmit the adv packet?
Then I can take a look and see if there is something there that could explain the issue.

Best regards

[radioschmadio]

void hal_radio_config(void) {

NVIC_DisableIRQ(RADIO_IRQn);

// cycle radio power
NRF_RADIO->POWER = RADIO_POWER_POWER_Disabled << RADIO_POWER_POWER_Pos;
NRF_RADIO->POWER = RADIO_POWER_POWER_Enabled << RADIO_POWER_POWER_Pos;

NRF_RADIO->TXPOWER=0x00; //set lowest tx power
NRF_RADIO->SHORTS = 0x000000000;

//length on air of S0, S1, and LFLEN
NRF_RADIO->PCNF0 =   (((1UL) << RADIO_PCNF0_S0LEN_Pos) & RADIO_PCNF0_S0LEN_Msk)
                   | (((2UL) << RADIO_PCNF0_S1LEN_Pos) & RADIO_PCNF0_S1LEN_Msk)
                   | (((6UL) << RADIO_PCNF0_LFLEN_Pos) & RADIO_PCNF0_LFLEN_Msk);

//little endian, base address length (3 + 1 = 4), static length = 0, max length, enable payload	
NRF_RADIO->PCNF1 =   (((RADIO_PCNF1_ENDIAN_Little)        << RADIO_PCNF1_ENDIAN_Pos) & RADIO_PCNF1_ENDIAN_Msk)
                   | (((3UL)                              << RADIO_PCNF1_BALEN_Pos)  & RADIO_PCNF1_BALEN_Msk)
                   | (((0UL)                              << RADIO_PCNF1_STATLEN_Pos)& RADIO_PCNF1_STATLEN_Msk)
                   | ((((uint32_t)DD_MAX_PAYLOAD_LENGTH)  << RADIO_PCNF1_MAXLEN_Pos) & RADIO_PCNF1_MAXLEN_Msk)
                   | ((RADIO_PCNF1_WHITEEN_Enabled << RADIO_PCNF1_WHITEEN_Pos) & RADIO_PCNF1_WHITEEN_Msk);

/* The CRC polynomial is fixed, and is set here. */
/* The CRC initial value may change, and is set by */
/* higher level modules as needed. */
NRF_RADIO->CRCPOLY = (uint32_t)CRC_POLYNOMIAL_INIT_SETTINGS;
NRF_RADIO->CRCCNF = (((RADIO_CRCCNF_SKIPADDR_Skip) << RADIO_CRCCNF_SKIPADDR_Pos) & RADIO_CRCCNF_SKIPADDR_Msk)
                  | (((RADIO_CRCCNF_LEN_Three)      << RADIO_CRCCNF_LEN_Pos)       & RADIO_CRCCNF_LEN_Msk);

	//enable reception on logical address, what does this mean?
NRF_RADIO->RXADDRESSES  = ( (RADIO_RXADDRESSES_ADDR0_Enabled) << RADIO_RXADDRESSES_ADDR0_Pos);

	//set BLE mode
NRF_RADIO->MODE    = ((RADIO_MODE_MODE_Ble_1Mbit) << RADIO_MODE_MODE_Pos) & RADIO_MODE_MODE_Msk;

	//interframe space in us between end tx and begin tx
NRF_RADIO->TIFS = 150;

	//something with access address?
NRF_RADIO->PREFIX0 = access_address[3];
NRF_RADIO->BASE0   = ( (((uint32_t)access_address[2]) << 24) 
                     | (((uint32_t)access_address[1]) << 16)
                     | (((uint32_t)access_address[0]) << 8) );
											 
/* set dev match address */									 
NRF_RADIO->DAB[0] = 0x4ae67dbe;  // 32 least significant
NRF_RADIO->DAP[0] = 0x1172; //16 most significant
NRF_RADIO->DACNF = (0x1) | (0x100); //enable addrress0

//Initial value for CRC calculation.
NRF_RADIO->CRCINIT = ((uint32_t)seed[0]) | ((uint32_t)seed[1])<<8 | ((uint32_t)seed[2])<<16;
	
NRF_RADIO->DATAWHITEIV=37;
	
NRF_RADIO->FREQUENCY = CHANNEL_IDX_TO_FREQ_OFFS(37); // ERIC
	
NVIC_EnableIRQ(RADIO_IRQn);
	

}

Snippet that actually sends

	NRF_RADIO->EVENTS_DISABLED = 0;
NRF_RADIO->TASKS_DISABLE = 1;
while(!NRF_RADIO->EVENTS_DISABLED);     //wait for radio to be disabled

NRF_RADIO->EVENTS_READY=0;					 //clear flag
NRF_RADIO->TASKS_TXEN=1;						 //enable radio in TX mode
while(!NRF_RADIO->EVENTS_READY);     //wait for radio to be in tx mode

NRF_RADIO->PACKETPTR = (uint32_t)&thisdata;

NRF_RADIO->EVENTS_END = 0;					 //clear flag
NRF_RADIO->TASKS_START = 1;  		     //its ready start task
while(!NRF_RADIO->EVENTS_END); 	     //wait for radio to send

//clear event
NRF_RADIO->EVENTS_DISABLED = 0;
NRF_RADIO->EVENTS_END = 0;
NRF_RADIO->EVENTS_READY=0;

[radioschmadio]

Does the prefix / base have something to do with it?

[radioschmadio]

So if I send 0x8164D6 the receiver gets 0x812402, no errors flagged.

0xFFFFD6 receives as 0xFF3F02

0xFFFFFFFF receives as 0xFF3F03FF

0x12347856 receives as 0x12340056

0x4225BB receives as 0x422503

0x4217FFFF receives as 0x421703FF

[radioschmadio]

Nevermind, I am an idiot, thats S0, length, and S1. DUH.