Advice for simple communication from nrf51822 to nrf24l01 ?

RE: Advice for simple communication from nrf51822 to nrf24l01 ?

Matt — Tue, 01 Dec 2015 01:45:13 GMT

Finally got it! I tried those further changes to the rf24 library without luck. Did some more digging, and saw that in the latest library release for micro-esb on github they reversed the polarity of the NOACK flag. Changing back to the original fixed my problem. I guess I wasn't getting an ACK because I wasn't asking for one in my packet! :) I can now read ACK payloads as well. Thanks for all the help, Gavin!

RE: Advice for simple communication from nrf51822 to nrf24l01 ?

Gavin — Mon, 30 Nov 2015 23:30:24 GMT

The library I have for the RPi is clearly based on the Arduino one at maniacbug's GitHub repository - though someone has made some tweaks to port it for the RPi. I was convinced I had downloaded it from there but must be mistaken - my bad.

I have done a text comparison and found that apart from changes required to port to the RPi (minor language differences), there are a few more changes which you could try and replicate in your Arduino library. So aside from setting the EN_DYN_ACK registers as above:

comment out the flush_rx and flush_tx commands near the top of the startListening routine - just above the Go! comment (comments in mine say 'as per gcopeland fork')
Add 150 microsecond delays in the powerDown and powerUp routines after the write_register commands
comment out the powerDown and flush_tx commands from the end of the write routine
comment out the 150 microsecond delay at the start of the startWrite routine
adjust the 15 microsecond delay to 10 microseconds in the startWrite routine (beneath the Allons! comment)

The ackd=true command in my NRF51 code is safe to remove - it's one of my global vars that's specific to my application (which I didn't define in the code snippet)

RE: Advice for simple communication from nrf51822 to nrf24l01 ?

Matt — Mon, 30 Nov 2015 22:54:18 GMT

Interesting.. I'm still not able to get the nrf51822 to enter into the success portion of uesb_event_handler. It keeps going right into the tx failed section instead. I copy/pasted the same library you're using for micro esb without luck, but perhaps the difference lies in the RF24 library instead? which version are you using there? I'm on the one here.

Is there anything that may have been lost in your posted code due to the formatting? I did notice a few oddities, for example the 'ackd = true' line in your 51 code causes a compiler error and had to be removed.

I'm also trying to dig through to see if there may be any differences between the RPi version and Arduino that I may have missed.

RE: Advice for simple communication from nrf51822 to nrf24l01 ?

Gavin — Mon, 30 Nov 2015 21:46:50 GMT

The only other thing I can think of is that I am working off of an older version of Nordic's micro esb library on the NRF 51822- I wonder if something has changed that might be affecting behaviour? The one that I am using is here

RE: Advice for simple communication from nrf51822 to nrf24l01 ?

Gavin — Mon, 30 Nov 2015 21:18:21 GMT

Yes, am receiving acks to trigger the success portion of the uesb_event_handler. Occasional false-negatives when I am the edge of range, but generally it works.

Almost year ago, so my memory is a little hazy, but if I remember correctly it was the edit to the RF24.cpp file that sorted the problem.

RE: Advice for simple communication from nrf51822 to nrf24l01 ?

Matt — Mon, 30 Nov 2015 17:00:18 GMT

Hi Gavin, Thanks so much! This is super helpful. I got this up and running pretty well on an arduino, and can post back to my github for others once I'm done cleaning it up a bit.

One other question - when running this code are you properly receiving acks back to the 51822 that cause the success portion of the uesb_event_handler to run? I seem to only be entering the failed portion of that function.

RE: Advice for simple communication from nrf51822 to nrf24l01 ?

Gavin — Sun, 29 Nov 2015 00:38:59 GMT

Apologies for formatting issues (and abuse of commenting system for posting code)!

RE: Advice for simple communication from nrf51822 to nrf24l01 ?

Gavin — Sun, 29 Nov 2015 00:37:56 GMT

(3/3) Bare-bones of NRF51822 transmitting code:

#include "micro_esb.h"

#include "uesb_error_codes.h"

static uesb_payload_t tx_payload, rx_payload;

void uesb_event_handler() { static uint32_t rf_interrupts; static uint32_t tx_attempts;

uesb_get_clear_interrupts(&rf_interrupts);

if(rf_interrupts & UESB_INT_TX_SUCCESS_MSK)
{   
			ackd=true;
	}

if(rf_interrupts & UESB_INT_TX_FAILED_MSK)
{
    uesb_flush_tx();
}

if(rf_interrupts & UESB_INT_RX_DR_MSK)
{
    uesb_read_rx_payload(&rx_payload);
    NRF_GPIO->OUTCLR = 0xFUL << 8;
    NRF_GPIO->OUTSET = (uint32_t)((rx_payload.data[2] & 0x0F) << 8);
}

uesb_get_tx_attempts(&tx_attempts);
NRF_GPIO->OUTCLR = 0xFUL << 12;
NRF_GPIO->OUTSET = (tx_attempts & 0x0F) << 12;

}

int main(void) {

// Put power up high for testing purposes
uesb_set_tx_power(UESB_TX_POWER_4DBM);

// Set receive address
uint8_t rx_addr_p0[] = {0xD2, 0xF0, 0xF0, 0xF0, 0xF0};
uint8_t rx_addr_p1[] = {0xE1, 0xF0, 0xF0, 0xF0, 0xF0};
uint8_t rx_addr_p2   = 0x66;	

// Start the high-frequency clock - we'll need it for the radio
NRF_CLOCK->EVENTS_HFCLKSTARTED = 0;
NRF_CLOCK->TASKS_HFCLKSTART = 1;
while(NRF_CLOCK->EVENTS_HFCLKSTARTED == 0);	

// Configure the radio
uesb_config_t uesb_config       = UESB_DEFAULT_CONFIG;
uesb_config.rf_channel          = 5;
uesb_config.crc                 = UESB_CRC_16BIT;
uesb_config.retransmit_count    = 6;
uesb_config.retransmit_delay    = 500;
uesb_config.dynamic_ack_enabled = true;
uesb_config.protocol            = UESB_PROTOCOL_ESB_DPL;
uesb_config.bitrate             = UESB_BITRATE_1MBPS;
uesb_config.event_handler       = uesb_event_handler;

uesb_init(&uesb_config);
uesb_set_address(UESB_ADDRESS_PIPE0, rx_addr_p0);
uesb_set_address(UESB_ADDRESS_PIPE1, rx_addr_p1);
uesb_set_address(UESB_ADDRESS_PIPE2, &rx_addr_p2);

// Load the payload with some dummy information
tx_payload.length  = 13;
tx_payload.pipe    = 0;
tx_payload.data[0] = 0x01;
tx_payload.data[1] = 0x02;
tx_payload.data[2] = 0x03;
tx_payload.data[3] = 0x04;


while (true)
{

			// -------------- TRANSMIT ---------------------
		
			if(uesb_write_tx_payload(&tx_payload) == UESB_SUCCESS)
			{
					tx_payload.data[0]++;
			}
		
			nrf_delay_ms(100);
			
		
			
}

}

RE: Advice for simple communication from nrf51822 to nrf24l01 ?

Gavin — Sun, 29 Nov 2015 00:33:03 GMT

(2/3) Bare bones of the RPi code that calls the RF24 routines:

#include "../RF24.h";

RF24 radio("/dev/spidev0.0",8000000 , 25);
const int role_pin = 7; const uint64_t pipes[2] = { 0xF0F0F0F0E1LL, 0xF0F0F0F0D2LL };

void rf24setup(void){

radio.begin(); radio.setRetries( 15, 15); radio.setChannel(0x05); radio.setPALevel(RF24_PA_MAX); radio.setPALevel(RF24_PA_MAX); radio.setDataRate(RF24_1MBPS); radio.setPayloadSize(0x0c); radio.enableAckPayload();

radio.openWritingPipe(pipes[0]); radio.openReadingPipe(1,pipes[1]); radio.startListening(); radio.printDetails(); }

int main( int argc, char *argv[]){

// Declarations
uint8_t message[12];

    // Initialise radio (and print settings to screen)
    rf24setup();

// Finishing
while (1)
{
	radio.startListening(); // Start listening for incoming messages

	while ( ! radio.available() ) { // Wait for a message
		__msleep(10);
	}

	radio.read( &message,12); // Get the message

	// do something with message here	
            
	radio.stopListening(); // stop listening so we can send an acknowledgement
	radio.writeAckPayload(2,&message,13);
}

}

RE: Advice for simple communication from nrf51822 to nrf24l01 ?

Gavin — Sun, 29 Nov 2015 00:31:37 GMT

(1/3)

Apologies for the delay - been busy. The code below (spread over 3 messages) is running on a Raspberry Pi Model B with an NRF24L01 board, and an NRF51822 without softdevice.

At the RPi end, the enableAckPayload routine in maniacbug's RF24.cpp needs to be modified so that both the writeregister commands set the EN_DYN_ACK register too. ie. change from:

write_register(FEATURE,read_register(FEATURE) | _BV(EN_ACK_PAY) | _BV(EN_DPL) );

write_register(FEATURE,read_register(FEATURE) | _BV(EN_ACK_PAY) | _BV(EN_DPL) | _BV(EN_DYN_ACK) );

RE: Advice for simple communication from nrf51822 to nrf24l01 ?

Matt — Tue, 24 Nov 2015 17:04:31 GMT

Gavin, do you have any example code that you managed to get working with that maniacbug library for the RF24 and the nRF51 SDK? I'm trying to accomplish the same thing and having a bit of trouble.

RE: Advice for simple communication from nrf51822 to nrf24l01 ?

Gavin — Sun, 28 Dec 2014 12:07:36 GMT

This is quite an important post for people trying to get NRF51822s working with legacy NRF24 systems, and solved the problems that I was having with acking. I had to modify the RF24 library I was using to set the EN_DYN_ACK register.

Is there any reading I can do to better understand why this is necessary?

RE: Advice for simple communication from nrf51822 to nrf24l01 ?

Håkon Alseth — Mon, 24 Mar 2014 08:51:33 GMT

Glad to hear it worked. I do not think anyone can replicate that great piece of hair. ;-)

RE: Advice for simple communication from nrf51822 to nrf24l01 ?

Cedric Honnet — Mon, 24 Mar 2014 06:15:26 GMT

Thanks a lot for your answer Håkon, it works ! Cedric.

PS: you mustache rocks, but my haircut is unique, lol ;p

RE: Advice for simple communication from nrf51822 to nrf24l01 ?

Håkon Alseth — Fri, 21 Mar 2014 11:01:55 GMT

Hi Cedric,

The nRF51 does not have the enhanced shockburst in hardware anymore, which means that when you send a payload from the nRF51 side, and the L01+ is configured to do auto-ACKing, you will run into issues.

What I would suggest is that you use the ESB-library on the nRF51 side, and on the nRF24L-side you enable registers:

EN_DPL for your pipes.
EN_DYN_ACK
EN_ACK_PAY

If you look at the ESB library documentation, there's a section on how the nRF24LE1 should be configured (see the nRFgo SDKs hal_nrf.c file for reference to the calls, its basically the registers I posted): devzone.nordicsemi.com/.../a00139.html

Best regards Håkon