Circuit Documentation

Summary

This circuit is designed to interface a load cell with an Arduino Mega 2560 using an HX711 bridge sensor interface. The Arduino Mega 2560 also controls multiple servos and an LCD display. Power is supplied through a 12V power supply, regulated down to 5V using an XL4015 DC-DC buck converter.

Component List

1. Load Cell - Red/white/black/green

   • Description: A load cell used for measuring weight.
   • Pins: E+, A-, E-, A+

2. HX711 - Bridge Sensor Interface

   • Description: An interface for bridge sensors like load cells.
   • Pins: E+, E-, A-, A+, B-, B+, GND, DATA (OUT), SCK (IN), 3.3/3.5V Supply

3. Arduino Mega 2560

   • Description: A microcontroller board based on the ATmega2560.
   • Pins: IOREF, RESET, 3V3, 5V, GND, VIN, A0-A15, D0-D53, PWM pins, AREF, SDA, SCL

4. LCD 16x2 (Wokwi Compatible)

   • Description: A 16x2 character LCD display.
   • Pins: VSS, VDD, V0, RS, RW, E, D0-D7, A, K

5. Servo

   • Description: A servo motor for precise control of angular position.
   • Pins: gnd, vcc, pulse

6. XL4015 5A DC Buck Step-down

   • Description: A DC-DC buck converter for stepping down voltage.
   • Pins: Output +, Output -, Input +, Input -

7. 12V Power Supply

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

Wiring Details

Load Cell - Red/white/black/green

• E+ connected to HX711 E+
• A- connected to HX711 E-
• E- connected to HX711 A-
• A+ connected to HX711 A+

HX711 - Bridge Sensor Interface

• E+ connected to Load Cell E+
• E- connected to Load Cell A-
• A- connected to Load Cell E-
• A+ connected to Load Cell A+
• GND connected to Arduino Mega 2560 GND
• DATA (OUT) connected to Arduino Mega 2560 D3 PWM
• SCK (IN) connected to Arduino Mega 2560 D2 PWM
• 3.3/3.5V Supply connected to Arduino Mega 2560 5V

Arduino Mega 2560

• 5V connected to HX711 3.3/3.5V Supply, LCD VDD, LCD A, XL4015 Output +, Servo vcc
• GND connected to HX711 GND, LCD VSS, LCD K, LCD RW, XL4015 Output -, Servo gnd
• D3 PWM connected to HX711 DATA (OUT)
• D2 PWM connected to HX711 SCK (IN)
• D14/TX3 connected to Servo pulse
• D4 PWM connected to LCD D4
• D5 PWM connected to LCD D5
• D6 PWM connected to LCD D6
• D7 PWM connected to LCD D7
• D8 PWM connected to LCD RS
• D9 PWM connected to LCD E
• D10 PWM connected to Servo pulse
• D11 PWM connected to Servo pulse
• D12 PWM connected to Servo pulse
• D13 PWM connected to Servo pulse

LCD 16x2 (Wokwi Compatible)

• VSS connected to Arduino Mega 2560 GND
• VDD connected to Arduino Mega 2560 5V
• V0 (contrast adjustment, typically connected to a potentiometer)
• RS connected to Arduino Mega 2560 D8 PWM
• RW connected to Arduino Mega 2560 GND
• E connected to Arduino Mega 2560 D9 PWM
• D4 connected to Arduino Mega 2560 D4 PWM
• D5 connected to Arduino Mega 2560 D5 PWM
• D6 connected to Arduino Mega 2560 D6 PWM
• D7 connected to Arduino Mega 2560 D7 PWM
• A connected to Arduino Mega 2560 5V
• K connected to Arduino Mega 2560 GND

Servo

• gnd connected to Arduino Mega 2560 GND
• vcc connected to Arduino Mega 2560 5V
• pulse connected to Arduino Mega 2560 D14/TX3, D10 PWM, D11 PWM, D12 PWM, D13 PWM

XL4015 5A DC Buck Step-down

• Output + connected to Arduino Mega 2560 5V
• Output - connected to Arduino Mega 2560 GND
• Input + connected to 12V Power Supply +
• Input - connected to 12V Power Supply -

12V Power Supply

• + connected to XL4015 Input +
• - connected to XL4015 Input -

Documented Code

Arduino Mega 2560 Code (sketch.ino)

void setup() {
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:

}

Additional Documentation (documentation.txt)

This documentation provides a comprehensive overview of the circuit, including a summary, detailed component list, wiring details, and the code used in the microcontroller.