What you need: any R1BBIT board, an ESP32 with R1BBIT firmware for Wi-Fi connection, 1 breadboards, 4 LEDs, one 1 kΩ resistor, and some jumper wires.
Connect the positive legs of the LEDs to outputs OUT1–OUT4, and route GND through the 1 kΩ resistor.
On your smartphone, add 4 widgets with commands to execute OUT1 ON / OUT1 OFF (and the same for OUT2–OUT4) for each LED — and you’re done.
Power the board, and toggling the corresponding widget will turn each LED on or off.
Just 5 minutes to assemble, and you have a colorful working project. Instead of LEDs, you can control various low-voltage devices, or high-voltage equipment through relays. R1BBIT ONE and MINI boards even include 4 and 2 built-in high-voltage relays.
Widgets are a key feature of the R1BBIT ecosystem, simplifying control down to zero lines of code for many devices.
In the same way, you can control four PWM outputs and generate signals of the desired frequency directly from widgets.