nRF52832 ESB Rx/Tx

[HoTiX]

Hi,

I am using 2 nRF52832, one for ESB Tx and one for ESB Rx used to send payload through UART using SDK11.

Tx board is used has a low power transmitter which transmit data on power up and shutdown after transmission as succeeded using event flag NRF_ESB_EVENT_TX_SUCCESS.

Rx board is used to retrieve those intermittent payload with event flag NRF_ESB_EVENT_RX_RECEIVED. Once a payload is received, it is send to uart via app_uart_put. This works great. The problems we have is that we require a call to nrf_esb_flush_rx after receiving the first payload, otherwise no payload will ever be received again. With the flush_rx call, the Rx works forever without trouble. In some rare occasion, we will receive 2 payload, back-to-back (normal use-case). Using the nrf_esb_flush_rx, the second payload is always drop from the rx_fifo. Why is the nrf_esb_flush_rx require ?

As a starting point, we used the esb_low_power_prx/ptx example and stripping out all the LEDs/gpio part. Prior to that, pressing a button didn't required the nrf_esb_flush_rx to works.

Attached, is the simplex prx code to reproduce the problem. prx.cpp ptx.cpp

Any help would be appreciated.

HoTiX

[Anders Strand]

Hello.

I flashed a nRF52 DK with the esb_Iow_power_ptx example. I took the SDK11 esb_low_power_PRX example, and swapped our main.c with the prx.cpp you provided. To compile it with Keil, i had to comment out some lines:

//extern "C" {
//#include "app_uart.h"
//}    

// FIXME
//#ifdef APP_ERROR_CHECK
//#undef APP_ERROR_CHECK
#define APP_ERROR_CHECK(err_code) if(err_code) nrf_esb_error_handler(err_code, __LINE__);
//#endif

I added some printing over RTT to see if i received packets.

// Without this, program get stuck after first payload received.
            	//nrf_esb_flush_rx();
                NRF_LOG_PRINTF("Received RX packet\n");

I then flashed this code to a nRF52 DK. Everything works fine, i receive a packet every time i press a button on the PTX.

So then we must take a closer look on your project.

• Have you changed the low_power_ptx code at all? If yes, can you post it?
• Have you changed any other files in the ESB library? For example RX fifo size or similar?

Just some general thoughts: If received packets to not generate a callback of the event handler, it could be because of this:

• The packet arrived while (or before) the application code handled the previous event.
• There is already packets in the rx fifo, a new packet will not generate an event. This might be why the rx flush solves the problem, as new packets will again generate events.

-Anders

[HoTiX]

I just uploaded the PTX we use to reproduce the problem. The ptx really just power up, init everything, send payload, wait for TX_SUCCESS, then shutdown. It is power on again every seconds to send another payload. These are the only file we changed.