The ESP32 is the successor to the famous ESP8266.
There are a few variations of the dev kit boards available - but which to choose?
Here we have the ESP32S NodeMCU V1.1 next to the AI Thinker DevKitV1
When placed in a breadboard you can see the DevKitV1 board leaves no room on the sides while the NodeMCU leaves 1 pin on each side.
The DevKitV1 module shows the pin labels on the top of the board, while the NodeMCU board has pin labels underneath
The NodeMCU seems to offer more pins, but many of these pins are unusable without careful considerations due to the fact that they are shared with the onboard SPI flash chip. The usable pins are identical but do have a different layout.
2019-08-27 First Published