[diafygi]

Is there an hobby equivalent for Bluetooth Low Energy (BLE)? Wifi tends to be power hungry for battery-operated devices. With BLE, you can get months of lifespan while still being able to connect to it with your phone.

I was looking at the micro:bit, but it's still $15. Anything in the $2 range for BLE?

[StavrosK]

Try the ESP32, it might fit the bill, although I've never worked with its Bluetooth capabilities and don't know much about them.

[wybiral]

I've experimented with those ESP32 chips from a few sources on a handful of boards (lots of cheapo knockoffs floating around) and haven't been happy with the performance or reliability of any of them for BLE. So far Nordic nRF52 holds the lead in my experience (they do cost a bit more though).

[jsjohnst]

Nordic is good, but STM32 is also affordable and quite decent.

[makomk]

There are some cheap nRF51822 modules from China which come close to that price range. You might even be able to get them working with the open source Apache Mynewt stack, though I never got around to trying.

[ohazi]

I wouldn't use an esp32 if your concern is power consumption, as they tend to be pretty power hungry, even when they're only doing BLE. The Nordic nRF52 series is pretty good, and you can find shielded modules for around $10-15 in single unit quantities.

$2 is a bit of a stretch... You can probably get the bare IC for ~$5 if you're willing to do the antenna yourself.

[Jedd]

It sounds like you're after closer-range than this is intended for, and I've no idea on relative power consumption - but you may want to check out LoRa [1]. More Zigbee-alike than BT(LE)-alike.

[1] https://en.wikipedia.org/wiki/LoRa

[zokier]

ESP32 does BLE