Dynamic switching of prefixes not working with ESB

RE: Dynamic switching of prefixes not working with ESB

Kenneth — Mon, 20 Jan 2020 14:56:30 GMT

It may be that the ESB protocol is not what you need. Dynamically changing PTX/PRX mode is not something that is common use case with ESB (there may be race conditions that is not met, that prevent it to work as intended). Maybe you can build your application on the very simple:

\nRF5_SDK_16.0.0_98a08e2\examples\peripheral\radio

Best regards,
Kenneth

RE: Dynamic switching of prefixes not working with ESB

henryh — Mon, 20 Jan 2020 14:34:10 GMT

I have verified that the master is hung after switching back to PTX from PRX. In this state there is no NRF_ESB_EVENT_SUCCESS" in ESB event handler despite nrf_esb_write_payload() returning a "SUCCESS" exit code. When there is no mode swapping I get the NRF_ESB_EVENT_SUCCESS" in the event handler after writing a payload. I suspect it is waiting for an ACK even though I have SELECTIVE_ACK true and payload NO_ACK true.

RE: Dynamic switching of prefixes not working with ESB

henryh — Mon, 20 Jan 2020 13:42:55 GMT

I've been unable to resolve this issue and have moved to a system where one pipe is used for both RX and TX. In this system there is a master and multiple slaves. The master broadcasts a beacon packet that is received by all slaves, this beacon defines time slot 0 and the slaves synchronize to it. At the end of time slot 0 the master changes to PRX and the slaves to PTX to provide for packet from the slave to the master. At the end of the last time slot the modes are again changed with master as PTX and slave as PRX. All transmissions are NO_ACK so selective ACK is true and packet NO_ACK is true at all times. I have the beacon in this system working but when I change modes, the radio hangs. Right now I call nrf_esb_init() each time I change modes (followed by nrf_esb_rx_start() for PRX). Calling nrf_esb_init() without a change in mode does not hang the system. Any ideas?

RE: Dynamic switching of prefixes not working with ESB

Kenneth — Wed, 15 Jan 2020 18:11:21 GMT

That might be it. If the PTX is transmitting a payload using nrf_esb_write_payload(e.g. retransmit_count = 0..n or tx_payload.noack = true), is there any reason why you can't wait for the nrf_esb_event_handler() return NRF_ESB_EVENT_TX_SUCCESS, NRF_ESB_EVENT_RX_RECEIVED or NRF_ESB_EVENT_TX_FAILED?

Then the radio should be in idle state (e.g. check nrf_esb_is_idle()) and you call nrf_esb_update_prefix()?

RE: Dynamic switching of prefixes not working with ESB

henryh — Wed, 15 Jan 2020 17:24:04 GMT

Looks like I am getting stuck when the PTX sends a payload using ACK w/payload and doesn't receive and answer. This leaves the radio in the NRF_ESB_STATE_PTX_RX_ACK state (the prefix cannot be changed unless in IDLE). Ideally I would remove the packet from the TX FIFO and clear the NRF_STATE_PTX_RX_ACK state from the stack. I tried disabling, re-initialize and update prefix but it does not seem to work. Any suggestions?

RE: Dynamic switching of prefixes not working with ESB

Kenneth — Wed, 15 Jan 2020 07:59:45 GMT

Very odd. Have you tried to debug the RADIO peripheral before and after changing the prefix?

Keil: When debug click Peripherals->Sysem Viewer->Radio, then you can see all radio registers, and which change when single stepping code.

SES: When debug click on the Registers window->Groups and select Radio. Example:

Best regards,
Kenneth

RE: Dynamic switching of prefixes not working with ESB

henryh — Tue, 14 Jan 2020 21:31:47 GMT

There are no re-transmission since it is set to 0 in the nrf_esb_init() configuration. I've tried by bracketing the prefix change with nrf_esb_suspent() and nrf_tx_start() but no change. I've also tried to use nrf_esb_disable() before the prefix change with nrf_esb_init() following it but does not work. It seems that whenever I change the prefix, the pipe shuts down. Any suggestions?

RE: Dynamic switching of prefixes not working with ESB

Kenneth — Thu, 09 Jan 2020 18:00:41 GMT

Hi,

I am not quite sure, but make sure that the payload changes (e.g. add a counter in the payloads) this to ensure that the packet is not treated as a retransmit by the PRX (in which case it will ack to the PTX, but not inform the application on the PRX (since it is considered an retransmit)).

Have you tried to disable, reconfigure prefix and enable again, to see if that make any difference?

Best regards,
Kenneth