Circuit Documentation

Summary

This circuit integrates an Arduino UNO microcontroller with various sensors and modules, including an HX711 load cell amplifier, an MPU6050 accelerometer and gyroscope, an HC-SR04 ultrasonic sensor, an HC-05 Bluetooth module, and several LEDs. The circuit is designed to measure weight, detect orientation, measure distance, and communicate wirelessly via Bluetooth. Additionally, it includes a buzzer for alerting based on specific conditions.

Component List

1. Arduino UNO

   • Description: Microcontroller board based on the ATmega328P.
   • Pins: UNUSED, IOREF, Reset, 3.3V, 5V, GND, Vin, A0, A1, A2, A3, A4, A5, SCL, SDA, AREF, D13, D12, D11, D10, D9, D8, D7, D6, D5, D4, D3, D2, D1, D0

2. HX711 - Bridge Sensor Interface

   • Description: Load cell amplifier for weight measurement.
   • Pins: E+, E-, A-, A+, B-, B+, GND - GROUND, DATA (OUT), SCK - CLOCK (IN), 3.3/3.5V Supply

3. MPU6050

   • Description: Accelerometer and gyroscope sensor.
   • Pins: vcc, gnd, scl, sda, xda, xcl, AD0, int, 3.3v

4. Load Sensor - 50kg

   • Description: Load cell for weight measurement.
   • Pins: W, R, B

5. HC-SR04 Ultrasonic Sensor

   • Description: Ultrasonic distance sensor.
   • Pins: VCC, TRIG, ECHO, GND

6. LED: Two Pin (red)

   • Description: Red LED.
   • Pins: cathode, anode

7. LED: Two Pin (green)

   • Description: Green LED.
   • Pins: cathode, anode

8. LED: Two Pin (blue)

   • Description: Blue LED.
   • Pins: cathode, anode

9. Resistor (1k Ohms)

   • Description: Resistor with 1k Ohms resistance.
   • Pins: pin1, pin2

10. HC-05 Bluetooth Module

    • Description: Bluetooth module for wireless communication.
    • Pins: Key, VCC, TXD, RXD, State, GND

11. 7.4v Battery

    • Description: Power supply.
    • Pins: +, -

Wiring Details

Arduino UNO

• D9: Connected to TRIG of HC-SR04 Ultrasonic Sensor
• D10: Connected to ECHO of HC-SR04 Ultrasonic Sensor
• A5: Connected to scl of MPU6050
• A4: Connected to sda of MPU6050
• 5V: Connected to VCC of HX711 - Bridge Sensor Interface, HC-05 Bluetooth Module, HC-SR04 Ultrasonic Sensor, MPU6050
• GND: Connected to GND of HX711 - Bridge Sensor Interface, LED: Two Pin (blue), LED: Two Pin (red), LED: Two Pin (green), HC-05 Bluetooth Module, HC-SR04 Ultrasonic Sensor, MPU6050, 7.4v Battery
• Vin: Connected to + of 7.4v Battery
• D13: Connected to anode of LED: Two Pin (green)
• D12: Connected to anode of LED: Two Pin (red)
• D8: Connected to anode of LED: Two Pin (blue)
• D3: Connected to DATA (OUT) of HX711 - Bridge Sensor Interface
• D2: Connected to SCK - CLOCK (IN) of HX711 - Bridge Sensor Interface
• D1: Connected to RXD of HC-05 Bluetooth Module
• D0: Connected to TXD of HC-05 Bluetooth Module

HX711 - Bridge Sensor Interface

• E+, E-, A-: Connected to pin2 of Resistor
• 3.3/3.5V Supply: Connected to VCC of HC-05 Bluetooth Module, HC-SR04 Ultrasonic Sensor, MPU6050, 5V of Arduino UNO
• GND - GROUND: Connected to cathode of LED: Two Pin (blue), LED: Two Pin (red), LED: Two Pin (green), GND of HC-05 Bluetooth Module, HC-SR04 Ultrasonic Sensor, MPU6050, Arduino UNO
• A+: Connected to R of Load Sensor - 50kg
• DATA (OUT): Connected to D3 of Arduino UNO
• SCK - CLOCK (IN): Connected to D2 of Arduino UNO

MPU6050

• vcc: Connected to 5V of Arduino UNO
• gnd: Connected to GND of Arduino UNO
• scl: Connected to A5 of Arduino UNO
• sda: Connected to A4 of Arduino UNO

Load Sensor - 50kg

• W: Connected to pin1 of Resistor
• R: Connected to A+ of HX711 - Bridge Sensor Interface
• B: Connected to pin1 of Resistor

HC-SR04 Ultrasonic Sensor

• VCC: Connected to 5V of Arduino UNO
• TRIG: Connected to D9 of Arduino UNO
• ECHO: Connected to D10 of Arduino UNO
• GND: Connected to GND of Arduino UNO

LED: Two Pin (red)

• cathode: Connected to GND of Arduino UNO
• anode: Connected to D12 of Arduino UNO

LED: Two Pin (green)

• cathode: Connected to GND of Arduino UNO
• anode: Connected to D13 of Arduino UNO

LED: Two Pin (blue)

• cathode: Connected to GND of Arduino UNO
• anode: Connected to D8 of Arduino UNO

Resistor (1k Ohms)

• pin1: Connected to W of Load Sensor - 50kg, B of Load Sensor - 50kg
• pin2: Connected to E+, E-, A- of HX711 - Bridge Sensor Interface

HC-05 Bluetooth Module

• VCC: Connected to 5V of Arduino UNO
• TXD: Connected to D0 of Arduino UNO
• RXD: Connected to D1 of Arduino UNO
• GND: Connected to GND of Arduino UNO

7.4v Battery

• +: Connected to Vin of Arduino UNO
• -: Connected to GND of Arduino UNO

Documented Code

#include <Wire.h>
#include <Adafruit_MPU6050.h>
#include <Adafruit_Sensor.h>
#include <HX711_ADC.h>
#if defined(ESP8266) || defined(ESP32) || defined(AVR)
#include <EEPROM.h>
#endif

// Pins for HX711
const int HX711_dout = 4; // HX711 DOUT
const int HX711_sck = 5;  // HX711 SCK

// HX711 Object
HX711_ADC LoadCell(HX711_dout, HX711_sck);

// MPU6050
Adafruit_MPU6050 mpu;

// Ultrasonic sensor
const int trigPin = 9;
const int echoPin = 10;
long duration;
int distanceCm;
int oldValue = 0, newValue = 0;

// Buzzer
#define BUZZER_PIN 7
#define ANGLE_THRESHOLD 60.0 // Threshold in degrees

// EEPROM Address for HX711 Calibration
const int calVal_eepromAdress = 0;

// Timing variables
unsigned long t = 0;

void setup() {
  // Serial Communication
  Serial.begin(115200);
  Wire.begin();

  // HX711 Initialization
  LoadCell.begin();
  unsigned long stabilizingtime = 2000; 
  boolean _tare = true;
  LoadCell.start(stabilizingtime, _tare);
  if (LoadCell.getTare