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
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)
Todo: try flashing LEDs on all GPIOs to compare against NodeMCUs IO table
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