Circuit Documentation

Summary

This circuit integrates various sensors, modules, and a microcontroller to create a comprehensive system. The primary components include a Raspberry Pi 4B, multiple HX711 Weighing Sensor Modules, Load Cells, an OV7725 camera module, a WeMOS ESP8266, an MG90S servo motor, a Buzzer Module, LEDs, an Adafruit 24-Channel 12-bit PWM LED Driver, a bulb, and a 12V power supply. The Raspberry Pi 4B serves as the central processing unit, interfacing with the camera, weighing sensors, and other peripherals.

Component List

Raspberry Pi 4B

• Description: A powerful single-board computer used for various applications.
• Pins: 3V3, 5V, GPIO2, GPIO3, GND, GPIO4, GPIO14, GPIO15, GPIO17, GPIO18, GPIO27, GPIO22, GPIO23, GPIO24, GPIO10, GPIO9, GPIO25, GPIO11, GPIO8, GPIO7, ID_SD, GPIO5, GPIO6, GPIO12, GPIO13, GPIO19, GPIO16, GPIO26, GPIO20, GPIO21, ID_SC, TR01_TAP, TR00_TAP, TR03_TAP, TR02_TAP, RUN, GLOBAL_EN, ETH, HDMI 0, HDMI 1, CAMERA, AV

HX711 Weighing Sensor Module

• Description: A precision 24-bit analog-to-digital converter (ADC) designed for weigh scales and industrial control applications.
• Pins: B-, B+, A-, A+, E-, E+, VCC, CK/TX, DO/RX, GND

Load Cell - Red/white/black/green

• Description: A sensor used to measure weight or force.
• Pins: E+, A-, E-, A+

OV7725

• Description: A camera module used for capturing images and videos.
• Pins: 3V3, GND, SIOC, SIOD, VSYNC, HREF, PCLK, XCLK, D9, D8, D7, D6, D5, D4, D3, D2, RESET, D1, D0, PWDN

WeMOS ESP8266

• Description: A low-cost Wi-Fi microchip with full TCP/IP stack and microcontroller capability.
• Pins: A0, VIN, GND, 5V, 3.3V, D7, D6, D1, D2, D15, D14, D13, D12, D11, D10, 19, D8, D5, D4, D3, D0

MG90S

• Description: A micro servo motor used for precise control of angular position.
• Pins: SIG, VCC, GND

Buzzer Module

• Description: A module used to produce sound.
• Pins: GND, Vcc, I/O

LED: Two Pin (red)

• Description: A red LED used for indication.
• Pins: cathode, anode

LED: Two Pin (green)

• Description: A green LED used for indication.
• Pins: cathode, anode

Adafruit 24-Channel 12-bit PWM LED Driver - SPI

• Description: A driver used to control multiple LEDs with PWM signals.
• Pins: +24V, GND, DIN, CLK, OE, LAT, PWM0, PWM23, PWM1, PWM22, PWM2, PWM21, V+, PWM3, PWM20, PWM4, PWM19, PWM5, PWM18, PWM6, PWM17, PWM7, PWM16, PWM8, PWM15, PWM9, PWM14, VCC, PWM10, PWM13, PWM11, PWM12, DOUT

Bulb

• Description: A light bulb used for illumination.
• Pins: GND, power

12V Power Supply

• Description: A power supply providing 12V DC.
• Pins: +, -

Wiring Details

Raspberry Pi 4B

• 3V3 connected to 3V3 of OV7725
• GND connected to GND of OV7725, WeMOS ESP8266, MG90S, HX711 Weighing Sensor Modules, LED (red), LED (green), Buzzer Module, Adafruit 24-Channel 12-bit PWM LED Driver, and bulb
• GPIO2 connected to SIOD of OV7725
• GPIO3 connected to SIOC of OV7725
• GPIO5 connected to RESET of OV7725
• GPIO6 connected to PWDN of OV7725
• GPIO7 connected to D5 of OV7725
• GPIO8 connected to D6 of OV7725
• GPIO9 connected to LAT of Adafruit 24-Channel 12-bit PWM LED Driver
• GPIO10 connected to DIN of Adafruit 24-Channel 12-bit PWM LED Driver
• GPIO11 connected to CLK of Adafruit 24-Channel 12-bit PWM LED Driver
• GPIO12 connected to D4 of OV7725
• GPIO13 connected to OE of Adafruit 24-Channel 12-bit PWM LED Driver
• GPIO14 connected to D0 of WeMOS ESP8266
• GPIO15 connected to DO/RX of HX711 Weighing Sensor Module
• GPIO16 connected to D3 of OV7725
• GPIO17 connected to VSYNC of OV7725
• GPIO18 connected to XCLK of OV7725
• GPIO20 connected to D2 of OV7725
• GPIO21 connected to D1 of OV7725
• GPIO22 connected to PCLK of OV7725
• GPIO23 connected to D9 of OV7725
• GPIO24 connected to D8 of OV7725
• GPIO25 connected to D7 of OV7725
• GPIO26 connected to D0 of OV7725

HX711 Weighing Sensor Module

• DO/RX connected to D1 of WeMOS ESP8266 and GPIO15 of Raspberry Pi 4B
• CK/TX connected to D2 of WeMOS ESP8266
• GND connected to GND of MG90S, WeMOS ESP8266, Raspberry Pi 4B, and other HX711 modules
• VCC connected to 3.3V of WeMOS ESP8266 and 3V3 of Raspberry Pi 4B
• A- connected to A- of Load Cell
• A+ connected to A+ of Load Cell
• E- connected to E- of Load Cell
• E+ connected to E+ of Load Cell

Load Cell - Red/white/black/green

• A- connected to A- of HX711 Weighing Sensor Module
• A+ connected to A+ of HX711 Weighing Sensor Module
• E- connected to E- of HX711 Weighing Sensor Module
• E+ connected to E+ of HX711 Weighing Sensor Module

OV7725

• 3V3 connected to 3V3 of Raspberry Pi 4B
• GND connected to GND of Raspberry Pi 4B
• SIOC connected to GPIO3 of Raspberry Pi 4B
• SIOD connected to GPIO2 of Raspberry Pi 4B
• VSYNC connected to GPIO17 of Raspberry Pi 4B
• HREF connected to GPIO27 of Raspberry Pi 4B
• PCLK connected to GPIO22 of Raspberry Pi 4B
• XCLK connected to GPIO18 of Raspberry Pi 4B
• D9 connected to GPIO23 of Raspberry Pi 4B
• D8 connected to GPIO24 of Raspberry Pi 4B
• D7 connected to GPIO25 of Raspberry Pi 4B
• D6 connected to GPIO8 of Raspberry Pi 4B
• D5 connected to GPIO7 of Raspberry Pi 4B
• D4 connected to GPIO12 of Raspberry Pi 4B
• D3 connected to GPIO16 of Raspberry Pi 4B
• D2 connected to GPIO20 of Raspberry Pi 4B
• RESET connected to GPIO5 of Raspberry Pi 4B
• D1 connected to GPIO21 of Raspberry Pi 4B
• D0 connected to GPIO26 of Raspberry Pi 4B
• **