Gzll protocol lost connection if loss power occured

[chenyu]

Hi, I use Gzll protocol to realize 2.4G frequency hopping communication， Two Device send data to One Host on Pipe1 and Pipe2.

1 Two Devices occur "loss power" many times during communication,but the Host keeps on during this time, and then both of the two Devices lost connection from the Host.

2 Both two Devices don't run neither nrf_gzll_device_tx_success() nor nrf_gzll_device_tx_failed(); But it can run funciton in loop.

3 I use button to control Device run nrf_gzll_disable() and nrf_gzll_enable(). and then they can communicate once and lost again.

4 A foolish way is power down Device and Host ,and power on again.

HW & SW Environment: nrf51822QFAA , SDK9, Keil5, WithoutSoftDevice. Please help me analyse the probily reason and the way to solve the problem. thank you.

@Kenneth :You may understand better follow this flow chart

[Kenneth]

This doesn't sound familiar. If I understand you correct, you experience that if you power cycle the devices, then they can no longer communicate.

Does it also occur with the default project in the SDK for Gazell? E.g.:

\nRF5_SDK_11.0.0-2.alpha_bc3f6a0\examples\proprietary_rf\gzll\gzll_ack_payload

If your protocol depends on device and host change addresses on the fly, always make sure that the device stay in receive mode for a period of time after receiving a packet from the host (e.g. 20ms). This to ensure that the ACK in reverse direction is successfully sent, in case of interference there might be re-transmissions required.

So something along the lines of:

1. Device receive packet, and add ACK payload.

2. Device stay in receive mode for additional 20ms to ensure ACK is sent.

3. Device change address.

[chenyu]

Thanks you for your answer, Do you mean host can re-transmit Ack automaticly if ACK payload send fail?