Comment by mrlambchop
9 hours ago
re: wifi/ble together
That sounds like the crate didn't have coexistence enabled or the defaults were really odd - so much boring stuff to write about BLE/WiFi Coex, but the short is "the default settings" are pretty good for low bandwidth IoT devices.
I'll peek at the code out of interest :)
What OP says
> Turned out when slowed down SPI bus, it started working.
reeks of either RF interference issues or power rail issues. Power is not the strongest domain of anything RPi so that's where I'd look first.