LINE DETECTOR CIRCUIT USING ARDUINO NANO

Infrared signal reading circuit uses ESP32

The circuit uses the ESP32's existing RF and BLE to control the vehicle's unlocking

The circuit determines the volume, classifies waste and connects to IOT using sim and wifi, for waste collection application to accumulate points

Circuit for application use that QR and IOT

The electronic scale circuit uses RS232 to detect signals from the scale heads

Integrated control via SIM and WIFI, combined with expansion IC for practice learning

The control circuit uses Arduino and the Uno uses TB6560

MEGA practice circuit drawing controls motors and equipment

Application circuit for high-power remote control vehicles

Device control circuit via LoRa and WIFI waves for IOT farm applications

The circuit measures heart rate and some health parameters

Circuit drawing practice circuit using UART communication between Mega and Esp8266 and some sensors

Device and sensor control circuit using arduino nano and esp8266

Circuit designed for positioning applications using GPS combined with SIM 800L

Device control circuit via Internet combines ESP8266 and PIC16F1827

PIC16F877A microcontroller circuit combined with ESP8266

Timer control and sound playback circuit via WIFI and music playback circuit

The device control circuit uses Pi zero

Getway circuit uses PI ZERO combined with communication via LORA SPI uses LoRa RA02 for high-speed lora control applications for extended control applications via RF waves

Raspberry Pi and esp8266 communication circuit with control

The circuit uses BLE chip CC2541 for energy saving applications

PIC control circuit combines expansion IC and UART communication with esp8266

IOT circuits for aquaculture applications have a full range of sensor designs, dynamics and some expansions that can be customized according to needs.

Large truck control circuit used for vehicles carrying heavy objects

Coffee maker circuit uses PIC16F877A combined with esp8266

This is a simple green painted coffee machine test circuit

The car control circuit via Bluetooth uses a number of sensors and driver control

A practice circuit drawing combining Arduino nano and esp8266 with RFID and some other components

Door control circuit via wifi using esp8266

Below are some available PCBs, you can refer to it and learn the principles from it, it's quite basic and hope it will be useful to you.