[AlotOfReading]

If you want bargain basement processors with connectivity, Qualcomm is still selling many of the old CSR chips. The low end chips went for <$0.50 in volume and the power consumption was often barely worth measuring. We used to chuck them into products every time every time I lost an argument with the hardware team about whether 10-15 cents of BOM cost is worth 3 months of painful bringup.

[coupdejarnac]

Are you using fcc approved modules with the csr chips or the bare chips? I'd be interested in a really cheap bluetooth capable microcontroller. I plan to use the nrf52805 for my next product due to the low cost.

[AlotOfReading]

Sorry if that came across as an endorsement. I'd go with the nordic modules instead because the documentation and support will be much better. The development costs of weird, cheap wireless chips isn't worth chasing marginal BOM optimizations. Just don't go to the other extreme and spend $40 on an Intel SoC for your wireless thermometer like I've seen others do.

I haven't worked with CSR modules since I left that job around 2017, but the latest vendor toolchains for some chips were still on GCC 3 (~2005) at that time. We were taking bare reels and doing certification ourselves if it matters though.