I recently changed my personal “to do list” realizing a small card (hence the name NanoBoard…) to more easily use the well-known form ESP-01 based on the MCU ESP8266EX with adjoining WIFI interface:
The NanoBoard also contains the serial-USB adapter and a “expander” (optional) with 16 Individually configurable GPIOs.
In addition, a circuit is implemented for the automatic upload commanded by the IDE Arduino (no need to press any buttons), in addition to the possibility of feeding the coupon also by an external power supply.
It is primarily designed for the learning environment, I also added several LEDs and an I2C interface for easy connection, eg, a small OLED display.
I am currently waiting to receive a new version of the PCB that corrects some errors and introduces minor improvements.
I'll post here the details for the implementation and also some sample program.