Wholly derived from ajlitt's brilliant write-up of his equally excellent hack of an ESP8266 IoT module at https://hackaday.io/project/8678-rpi-wifi.
- Slim 65x30x0.8mm PCB mounts directly against the reverse of the Zero.
ESP-12E/F WiFi module in 1 or 4-bit SDIO mode gives ~40Mbps up/down.
Pi reboot detection to reset the ESP & ensure correct reloading of driver.
Full size SD socket option for memory cards / peripherals.
USB port duplicated on end shifts metalwork away from WiFi SD Cards.
Killer feature - power LED .