This project is based on the Instructable ESP01/01S RELAY MODULE TUTORIAL.
I put this together to make some use of the ESP-01S relay modules I bought on Aliexpress some time ago.
There are many versions of these modules, but the ones I have (ESP-01S Relay v1.0) are actually bugged.
In order to put them to work, I had to do a couple of things (otherwise it would refuse to run my code).
I struggled with this problem for quite some time, until I found this video: How to fix cheap ebay ESP8266 relay module.
The code makes use of the ESP8266WiFi library from Arduino core for ESP8266 WiFi chip.
Install Arduino IDE and ESP8266 Arduino Core. At the time I wrote this, the latest versions were 1.8.13 and 2.7.2 respectively.
Clone the project and open it on the Arduino IDE.
The code still does not make use of a WiFi Manager so you need to create a my_network.h file
containing the SSID/PASSWORD of the WiFi network the ESP-01S is supposed to connect. The file
should be created on the project's folder and should be like the following:
#define MY_SSID "<your wifi ssid>"
#define MY_PASSWORD "<your wifi password>"
If you are curious, I used this thing to flash my ESP-01S: https://www.aliexpress.com/item/33011980079.html. It works like a charm. No jumpers or switches to fiddle with.