Circuit Documentation

Summary

This circuit involves an Arduino Nano microcontroller interfacing with a load cell through an HX711 load cell amplifier. The circuit also includes a 20x4 I2C LCD for display purposes, a 7805 voltage regulator for power management, a rocker switch for power control, and a 7.4V battery as the power source.

Component List

1. Arduino Nano

   • Description: A small, complete, and breadboard-friendly board based on the ATmega328P.
   • Pins: D1/TX, D0/RX, RESET, GND, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11/MOSI, D12/MISO, VIN, 5V, A7, A6, A5, A4, A3, A2, A1, A0, AREF, 3V3, D13/SCK

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

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

3. SparkFun Load Cell Amplifier - HX711

   • Description: A precision 24-bit analog-to-digital converter (ADC) designed for weigh scales and industrial control applications to interface directly with a bridge sensor.
   • Pins: VDD, VCC, DAT, SCK, GND, B+, B-, A+, A-, AVDD

4. Lcd 20x4 i2c

   • Description: A 20x4 character LCD display with I2C interface.
   • Pins: GND, 5V, SCA, SCL

5. 7805

   • Description: A voltage regulator that outputs a stable 5V.
   • Pins: Vin, Gnd, Vout

6. Rocker Switch

   • Description: A switch used to control the power supply.
   • Pins: Output, Input

7. 7.4V Battery

   • Description: A 7.4V battery used as the power source.
   • Pins: +, -

Wiring Details

Arduino Nano

• D5 is connected to DAT on the HX711.
• D6 is connected to SCK on the HX711.
• VIN is connected to Output on the Rocker Switch.
• GND is connected to GND on the 7805, GND on the HX711, GND on the LCD, and - on the 7.4V Battery.
• A5 is connected to SCL on the LCD.
• A4 is connected to SCA on the LCD.

Load Cell - Red/white/black/green

• E+ is connected to AVDD on the HX711.
• A- is connected to A- on the HX711.
• E- is connected to GND on the HX711.
• A+ is connected to A+ on the HX711.

SparkFun Load Cell Amplifier - HX711

• DAT is connected to D5 on the Arduino Nano.
• SCK is connected to D6 on the Arduino Nano.
• VCC is connected to Output on the Rocker Switch.
• GND is connected to GND on the 7805, GND on the LCD, - on the 7.4V Battery, and GND on the Arduino Nano.
• AVDD is connected to E+ on the Load Cell.
• A- is connected to A- on the Load Cell.
• A+ is connected to A+ on the Load Cell.

Lcd 20x4 i2c

• 5V is connected to Output on the Rocker Switch.
• GND is connected to GND on the 7805, GND on the HX711, - on the 7.4V Battery, and GND on the Arduino Nano.
• SCL is connected to A5 on the Arduino Nano.
• SCA is connected to A4 on the Arduino Nano.

7805

• Vin is connected to + on the 7.4V Battery.
• Gnd is connected to GND on the HX711, GND on the LCD, - on the 7.4V Battery, and GND on the Arduino Nano.
• Vout is connected to Input on the Rocker Switch.

Rocker Switch

• Output is connected to VCC on the HX711, 5V on the LCD, and VIN on the Arduino Nano.
• Input is connected to Vout on the 7805.

7.4V Battery

• + is connected to Vin on the 7805.
• - is connected to GND on the 7805, GND on the HX711, GND on the LCD, and GND on the Arduino Nano.

Documented Code

Arduino Nano 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 detailed component list, wiring details, and the code used in the Arduino Nano microcontroller.