Build a compact low-power WiFi sensor/actuator with an Arduino Mini-Pro and a WiFi serial interface ESP-01.

The project allows to build a sensor with the following capabilites, supported by the atlib library:

-) UTC time function with 1 sec. accuracy

-) switch on/off the ESP-01 for power saving

-) HTTP POST/GET returning the content of the body

-) sufficient memory for sensor management code (like FFT)

The project uses the ESP-01 native firmware, not need to reflash the device. The atlib library wraps AT commands and simplifies coding.

The circuit can be mounted on a 7x9cm prototype board, but also on a protoboard, or on breadboard (see images).

The attached code runs using the atlib library (see link) to perform the above functions consuming 40% memeory on a Atmel328p (Arduino UNO, Nano, Mini-Pro).