This is a Raspberry Pi "hat" that houses and powers a CPU cooling fan and an ESP8266 ESP-12E NodeMCU/Arduino microcontroller.

This PCB is used in ostmoxy's printerX to provide a Wireless Access Point that enables users to configure their 3D printer's web server. This board can be used for any situation in which you need for a Raspberry Pi and an ESP8266 ESP-12E microcontroller to communicate serially. You'll be on your own for case design - we've got ours buried in our 3D printers!

Some details:

• The Raspberry Pi provides power to the fan and microcontroller.
• The Raspberry Pi and microcontroller have their RX and TX pins connected so that they can communicate serially without connecting a USB cable.
• The Raspberry Pi and microcontroller share a common ground.
• Option to power the Raspberry Pi CPU fan with either 3.3V or 5V leads.

Requires:

• A 2x20 (40-pin) female header strip, 2.54mm pitch (plug into Raspberry Pi GPIO pins)
• A 2-pin male header, 2.54 mm pitch (connect fan power)
• A 30mm CPU cooling fan for Raspberry Pi (3.3V or 5V - cools Raspberry Pi CPU)
• An ESP8266 ESP-12E

More details will become available at https://ostmoxy.com when our 3D printers become available.

Source code that we use for the microcontroller and Raspberry Pi is available here: https://github.com/appideasDOTcom/printerx/tree/master/WAP