I am working on a project where I haven't quite decided on some of the details, so I wanted a module that breaks out a lot of the ESP8266's pins, just to have as many options available as possible. Here is also a 5 minute video about it. The ESP-12e module seems like a good choice, with the added benefit of having 4MBytes of flash memory. ESP-12e module from Banggod So I ordered a pack of three from Bangood for just under 8 Euros. After quite a long wait they arrived and I had to take them to the workbench for a quick test drive, right away. Odd stuff A few things are a bit odd about these modules: The silkscreen is a very poor print quality The ADC pin is labelled ADG The GPIO labels are a mess. Eg: There is no GPIO0 (this is labelled GPIO6 instead) Where's GPOI0? Todo: try flashing LEDs on all GPIOs to compare against NodeMCUs IO table Basic configuration So after a little experimentation, this turned out the most basic configuration: Basic config for ESP-12e I plan to run this without a circuit board, so I'll simply shorten GPOI15 to ground and connect the "Chip Power Down" Pin (CH_PD) to 3.3V. The Module came preinstalled with some AT-firmware, I didn't much care about. Flashing new firmware To program new firmware, GPOI0 (which for some reason is GPIO6 here) needs to be connected to ground. I am a huge fan of NodeMCU, so I flashed that to the module. Ground GPIO6 (=GPIO0) to flash firmware via UART This goes without saying Connecting the serial-usb converter is unspectacular. Just the usual RXD-TXD / TXD-RXD thing. And don't forget to connect the ground wires. Connecting the USB2Serial converter