[ElectroNomad]

Can anyone suggest BLE-only microcontroller?

I wanted to build a smart-lock, but all the boards either also have Wi-Fi on-board (that eats a lot of power) or don’t have anything at all.

[montecarl]

I've just started to get into microcontrollers, but I have been playing with boards based on the NRF52840[0]. I'm using them to build an air quality monitor to measure CO2[1], volatile organic compounds[2], temperature and humidity.

I'd recommend the Adafruit NRF52840 Feather[3] or if you want a smaller version (that doesn't include a LiPo battery charger) get the ItsyBitsy nRF52840 Express[4].

I haven't used the Arduino or CircuitPython programming environments, I've just been using Arm GCC and Nordic's SDK.

[0] https://www.nordicsemi.com/Products/Low-power-short-range-wi...

[1] https://www.adafruit.com/product/4867

[2] https://www.adafruit.com/product/3709

[3] https://www.adafruit.com/product/4062

[4] https://www.adafruit.com/product/4481

[tpolzer]

The nrf52840 has a reasonable programming interface, good power consumption and can be bought as a USB breakout dongle for 10$.