Circuit Documentation

Summary

This circuit is designed to interface a load cell with an Arduino Mega 2560 microcontroller through a SparkFun Load Cell Amplifier (HX711). The load cell measures mechanical force and the HX711 amplifies the signal for the microcontroller to process. A servo motor is also included, which can be controlled by the Arduino based on the load cell's readings. Power is supplied by a 12V power supply, which is stepped down to a lower voltage suitable for the components using an XL4015 5A DC Buck Step-down converter.

Component List

Load Cell - Red/white/black/green

• A sensor that converts a force into an electrical signal.
• Pins: E+, A-, E-, A+

12V Power Supply

• Provides the main power source for the circuit.
• Pins: +, -

XL4015 5A DC Buck Step-down

• A voltage regulator that steps down the voltage from the power supply to a level suitable for the other components.
• Pins: Output +, Output -, Input +, Input -

SparkFun Load Cell Amplifier - HX711

• Amplifies the signal from the load cell for the Arduino to read.
• Pins: GND, CLK, DAT, VCC, YLW, GRN, WHT, BLK, RED, B-, B+

Arduino Mega 2560

• The main microcontroller unit that processes the input from the HX711 and controls the servo motor.
• Pins: Various digital and analog I/O, power, and ground pins.

Servo

• An actuator that can be positioned with PWM signals from the Arduino.
• Pins: gnd, vcc, pulse

Wiring Details

Load Cell - Red/white/black/green

• E+ connected to HX711 RED
• A- connected to HX711 WHT
• E- connected to HX711 BLK
• A+ connected to HX711 GRN

12V Power Supply

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

XL4015 5A DC Buck Step-down

• Input + connected to 12V Power Supply +
• Input - connected to 12V Power Supply -
• Output + connected to Servo vcc, HX711 VCC, and Arduino 5V
• Output - connected to Servo gnd, HX711 GND, and Arduino GND

SparkFun Load Cell Amplifier - HX711

• RED connected to Load Cell E+
• WHT connected to Load Cell A-
• BLK connected to Load Cell E-
• GRN connected to Load Cell A+
• VCC connected to XL4015 Output +
• GND connected to XL4015 Output -
• CLK connected to Arduino D4 PWM
• DAT connected to Arduino D5 PWM

Arduino Mega 2560

• 5V connected to XL4015 Output +
• GND connected to XL4015 Output -
• D4 PWM connected to HX711 CLK
• D5 PWM connected to HX711 DAT
• D6 PWM connected to Servo pulse

Servo

• gnd connected to XL4015 Output -
• vcc connected to XL4015 Output +
• pulse connected to Arduino D6 PWM

Documented Code

Arduino Mega 2560 - sketch.ino

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

}

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

}

Arduino Mega 2560 - documentation.txt

(No additional documentation provided)