nrf52840 esb send and receive bidirectional with nrf24l01 on other end

[berkutta]

Hello

I'm using an nrf52840 (PCA10059) together with an nrf24l01 (ESP32, MIRF Library).

My goal is to send a data packet from the nrf52840 which the nrf24l01 can receive, The nrf24l01 should then send a data packet back to the nrf52840.

This seems to be pretty straight forward in the MIRF Library:

	while(1) {
		//When the program is received, the received data is output from the serial port
		if (Nrf24_dataReady(&dev)) {
			Nrf24_getData(&dev, mydata.value);
			ESP_LOGI(pcTaskGetTaskName(0), "Got data:%lu", mydata.now_time);
			
			vTaskDelay(1);
			Nrf24_send(&dev, mydata.value);
			vTaskDelay(1);
			ESP_LOGI(pcTaskGetTaskName(0), "Wait for sending.....");
			if (Nrf24_isSend(&dev)) {
				ESP_LOGI(pcTaskGetTaskName(0),"Send success:%lu", mydata.now_time);
			} else {
				ESP_LOGW(pcTaskGetTaskName(0),"Send fail:");
			}
		}
		vTaskDelay(1);
	}

But I'm not sure how to implement this on the nrf52840. This is my current implementation. How can I send back in this implementation? I'm confused as there is just NRF_ESB_MODE_PTX and NRF_ESB_MODE_PRX but not both:

uint32_t esb_init(void)
{
    nrf_gpio_cfg_output(6);
    nrf_gpio_pin_set(6);

    uint32_t err_code;
    uint8_t base_addr_0[4] = {0xE7, 0xE7, 0xE7, 0xE7};
    uint8_t base_addr_1[4] = {0xC2, 0xC2, 0xC2, 0xC2};
    uint8_t addr_prefix[8] = {0xE7, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8};

    nrf_esb_config_t nrf_esb_config = NRF_ESB_LEGACY_CONFIG;

    nrf_esb_config.retransmit_count = 6;
    nrf_esb_config.selective_auto_ack = false;
    nrf_esb_config.protocol = NRF_ESB_PROTOCOL_ESB;
    nrf_esb_config.bitrate = NRF_ESB_BITRATE_2MBPS;
    nrf_esb_config.event_handler = nrf_esb_event_handler;
    nrf_esb_config.mode = NRF_ESB_MODE_PTX;
    nrf_esb_config.payload_length = 4;

    err_code = nrf_esb_init(&nrf_esb_config);
    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, 8);
    VERIFY_SUCCESS(err_code);

    nrf_esb_set_rf_channel(90);

    tx_payload.length = 4;
    tx_payload.pipe = 0;

    tx_payload.data[0] = 0;
    tx_payload.data[1] = 0;
    tx_payload.data[2] = 0;
    tx_payload.data[3] = 0;

    nrf_gpio_pin_clear(6);

    return NRF_SUCCESS;
}

int main(void)
{
    esb_init();

    while (1)
    {
        tx_payload.noack = false;
        nrf_esb_write_payload(&tx_payload);
        
        nrf_delay_ms(10);
    }
}

[Kenneth]

Do you know the radio configuration used by the "MIRF library"? E.g. channel, address, dynamic payload size or not etc?

In general you can find that the nRF5 SDK are backwards compatible with the nRFgo SDK examples for the nRF24-series provided the following:
https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.1.0/esb_users_guide.html#esb_backwards 

However it is very likely that some of the radio configuration on the nRF24L01 is different in this case.

Kenneth

[berkutta]

Thanks for the Answer. Sending Data back and forth between nRF5 SDK and nRF24L01 with MIRF works. But just unidirectional.

Where can I find a nRF5 SDK Example or Documentation on how to receive ESB data with nRF5 SDK after Transmitting data?

[Kenneth]

I do believe that the \examples\proprietary_rf\esb_ptx show this in the nRF5 SDK, look at the handling of NRF_ESB_EVENT_RX_RECEIVED in the nrf_esb_event_handler() callback.

Kenneth

[berkutta]

Got it now working to send Packets "Ping Pong" style between nRF52840 and nRF24L01 (ESP32 SOC - MIRF SW). There was a missing Nrf24_setTADDR on the ESP32 side.

After that it's just a question of creating a loop like following to send packets from the nRF5 which can be answered by the nRF24L01:

    while(1) {
        tx_payload.noack = false;
        err_code = nrf_esb_write_payload(&tx_payload);
        VERIFY_SUCCESS(err_code);

        tx_payload.data[0]++;

        nrf_delay_ms(10);

        nrf_esb_start_rx();

        nrf_delay_ms(100);

        nrf_esb_stop_rx();
    }