ESP8266 + SDcard + Arduino bootloader = 10$ arduino-compatible standalone datalogger
The ESP8266 can be re-flashed to allow uploading Arduino skecthes.
It also has native support for SD card.
So, a single board which includes ESP8266, an SDcard reader and battery connector would be a cool, wifi and cheap standalone datalogger (no need for external MCU).
ESP3212, just arrived to the market, even supports Bluetooth!
Adminae (Admin, Seeedstudio) commented
That's cool. Thank for your suggestion.