My company has an application that utilizes BLE to connect to a mobile device and then uses the the QAPI HMI API to access 802.15.4 to communicte between devices. We are using the QCA 4020.
When commands come in over BLE, they are ultimately forwarded over HMI to other devices on the network. There are direct commands as well as broadcasts (to address 0xFFFF).
Occasionally we see channel access failures (QAPI_HMI_STATUS_CODE_CHANNEL_ACCESS_FAILURE) in the logs, however after a few retries it seems to recover. The error seems to be thrown more consistently when the BLE and HMI/802.15.4 connections are active at the same time (mobile device is connected and sending commands to the network).
Any ideas why the channel access error is being thrown?