Project Documentation

Arduino UNO-Based Yarn Tension Adjuster with OLED Display and Load Cell

Circuit Documentation

Summary

This circuit is designed to control a yarn tension adjustment system. It utilizes an Arduino UNO microcontroller to interface with various components including an OLED display, pushbuttons, a load cell with an HX711 interface, and a motor driver to control two 12V geared motors. The system reads the tension from the load cell, displays the set and actual tension values on the OLED display, and allows the user to adjust the set tension using pushbuttons.

Component List

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
0.96" OLED
- Description: Small OLED display module.
- Pins: GND, VDD, SCK, SDA
Pushbutton
- Description: Simple pushbutton switch.
- Pins: Pin 2, Pin 1, Pin 3, Pin 4
Pushbutton
- Description: Simple pushbutton switch.
- Pins: Pin 2, Pin 1, Pin 3, Pin 4
HX711 - Bridge Sensor Interface
- Description: Load cell amplifier and ADC.
- Pins: E+, E-, A-, A+, B-, B+, GND - GROUND, DATA (OUT), SCK - CLOCK (IN), 3.3/3.5V Supply
Load Cell - Red/white/black/green
- Description: Load cell sensor for measuring weight or force.
- Pins: E+, A-, E-, A+
12V Geared Motor
- Description: DC motor with gear reduction.
- Pins: Terminal 1, Terminal 2
12V Geared Motor
- Description: DC motor with gear reduction.
- Pins: Terminal 1, Terminal 2
L298N DC Motor Driver
- Description: Dual H-Bridge motor driver.
- Pins: OUT1, OUT2, 12V, GND, 5V, OUT3, OUT4, 5V-ENA-JMP-I, 5V-ENA-JMP-O, +5V-J1, +5V-J2, ENA, IN1, IN2, IN3, IN4, ENB

Wiring Details

Arduino UNO

3.3V: Connected to VDD of 0.96" OLED
5V: Connected to 3.3/3.5V Supply of HX711 - Bridge Sensor Interface
GND: Connected to GND of 0.96" OLED, GND - GROUND of HX711 - Bridge Sensor Interface, and Pin 1 of both Pushbuttons
A4: Connected to SDA of 0.96" OLED
A5: Connected to SCK of 0.96" OLED
D8: Connected to SCK - CLOCK (IN) of HX711 - Bridge Sensor Interface
D7: Connected to DATA (OUT) of HX711 - Bridge Sensor Interface
D6: Connected to Pin 3 of Pushbutton
D5: Connected to Pin 3 of Pushbutton
D4: Connected to IN1 of L298N DC Motor Driver
D3: Connected to ENB of L298N DC Motor Driver
D2: Connected to IN2 of L298N DC Motor Driver

0.96" OLED

GND: Connected to GND of Arduino UNO
VDD: Connected to 3.3V of Arduino UNO
SCK: Connected to A5 of Arduino UNO
SDA: Connected to A4 of Arduino UNO

Pushbutton

Pin 1: Connected to GND of Arduino UNO
Pin 3: Connected to D6 of Arduino UNO

Pushbutton

Pin 1: Connected to GND of Arduino UNO
Pin 3: Connected to D5 of Arduino UNO

HX711 - Bridge Sensor Interface

3.3/3.5V Supply: Connected to 5V of Arduino UNO
GND - GROUND: Connected to GND of Arduino UNO
SCK - CLOCK (IN): Connected to D8 of Arduino UNO
DATA (OUT): Connected to D7 of Arduino UNO

Load Cell - Red/white/black/green

E+: Connected to E+ of HX711 - Bridge Sensor Interface
E-: Connected to E- of HX711 - Bridge Sensor Interface
A-: Connected to A- of HX711 - Bridge Sensor Interface
A+: Connected to A+ of HX711 - Bridge Sensor Interface

12V Geared Motor

Terminal 1: Connected to OUT1 of L298N DC Motor Driver
Terminal 2: Connected to OUT2 of L298N DC Motor Driver

12V Geared Motor

Terminal 1: Connected to OUT4 of L298N DC Motor Driver
Terminal 2: Connected to OUT3 of L298N DC Motor Driver

L298N DC Motor Driver

IN1: Connected to D4 of Arduino UNO
ENB: Connected to D3 of Arduino UNO
IN2: Connected to D2 of Arduino UNO

Code Documentation

#include <Arduino.h>
#include <Keypad.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include "HX711.h"
#include "L298N_MotorDriver.h"

// OLED display
Adafruit_SSD1306 DIS = Adafruit_SSD1306(128, 64, &Wire);

// Motor driver
L298N_MotorDriver motor(3, 2, 4);

// Load cell
const int LOADCELL_DOUT_PIN = 8;
const int LOADCELL_SCK_PIN = 7;
HX711 scale;

// Button pins
int sw1 = 5;
int sw2 = 6;
int sw3 = 9;
int sw4 = 10;

// Variables
boolean run = 1;
int set = 50;
int actual = 502;
long sensee;
int scl;

// Button handling
const int increaseButtonPin = 5; // Pin for the increase button
const int decreaseButtonPin = 6; // Pin for the decrease button
int setValue = 400; // Variable to store the set value
int lastIncreaseState = HIGH; // Last state of the increase button
int lastDecreaseState = HIGH; // Last state of the decrease button

void setup() {
  // Pin modes
  pinMode(13, OUTPUT);
  pinMode(sw1, INPUT_PULLUP);
  pinMode(sw2, INPUT_PULLUP);
  pinMode(sw3, INPUT_PULLUP);
  pinMode(sw4, INPUT_PULLUP);

  // Serial communication
  Serial.begin(57600);

  // Initialize load cell
  scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);

  // Initialize OLED display
  DIS.begin(SSD1306_SWITCHCAPVCC, 0x3C);

  // Initialize motor driver
  motor.setDirection(true); // Sets the direction (depending on the wiring)
  motor.enable();
}

void diss() {
  DIS.clearDisplay();
  DIS.setTextColor(WHITE);
  DIS.setTextSize(1);
  DIS.setCursor(7, 0);
  DIS.print("YARN TENSION ADJST");

  DIS.setTextSize(2);
  DIS.setCursor(10, 22);
  DIS.print("SET");

  DIS.setTextSize(2);
  DIS.setCursor(10, 45);
  DIS.print("ACT");

  DIS.setCursor(70, 22);
  DIS.print(set);

  DIS.setCursor(70, 45);
  DIS.print(scl);

  DIS.display();
  DIS.dim(false);
}

void load() {
  if (scale.is_ready()) {
    long reading = scale.read();
    sensee = reading / 100.0;
    scl = map(sensee, 2853, 3300, 0, 1000);
  } else {
    Serial.println("HX711 not found.");
  }
}

void loop()