Other Arduino Codes and Videos by Robojax
This code is to measure current using Allegro ACS758 Current Sensor and display it on SSD1306 OLED Display of size 128x32 and 128x64
In order to use this code, you must watch the following two videos and get required library and codes
/*
* Arduino Sketch for Allegro ACS758 Current Sensor with SSD1306 OLED Display
* can be used with 128x64 or 128x32 OLED display with SSD1306 chip
* this sensor can measure current at range of up to 200A
* It operates with 3.3 or 5V
* This video requires you to watch the following 2 videos before using this code:
* 1- ACS758 Sensor https://www.youtube.com/watch?v=SiHfjzcqnU4
* 2- SSD1306 OLED Display https://www.youtube.com/watch?v=UmYiHTOz-5k
*
* View the video instruction for this code at https://youtu.be/aHg9UrK9s9c
* Written by Ahmad Shamshiri for Robojax Video channel www.Robojax.com
* Date: June 24, 2018, at 21:44 in Ajax, Ontario, Canada
* Permission granted to share this code given that this
* note is kept with the code.
* Disclaimer: this code is "AS IS" and for educational purpose only.
* this code has been downloaded from http://robojax.com/learn/arduino/
*
*/
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define OLED_RESET 4
Adafruit_SSD1306 display(OLED_RESET);
#define NUMFLAKES 10
#define XPOS 0
#define YPOS 1
#define DELTAY 2
#define LOGO16_GLCD_HEIGHT 64
#define LOGO16_GLCD_WIDTH 128
static const unsigned char PROGMEM logo16_glcd_bmp[] =
{ B00000000, B11000000,
B00000001, B11000000,
B00000001, B11000000,
B00000011, B11100000,
B11110011, B11100000,
B11111110, B11111000,
B01111110, B11111111,
B00110011, B10011111,
B00011111, B11111100,
B00001101, B01110000,
B00011011, B10100000,
B00111111, B11100000,
B00111111, B11110000,
B01111100, B11110000,
B01110000, B01110000,
B00000000, B00110000 };
#if (SSD1306_LCDHEIGHT != 64)
#error("Height incorrect, please fix Adafruit_SSD1306.h!");
#endif
///*** ACS758 settings starts
#define VIN A0 // define the Arduino pin A0 as voltage input (V in)
const float VCC = 5.0;// supply voltage 5V or 3.3V. If using PCB, set to 5V only.
const int model = 2; // enter the model (see below)
float cutOffLimit = 1.00;// reading cutt off current. 1.00 is 1 Amper
/*
"ACS758LCB-050B",// for model use 0
"ACS758LCB-050U",// for model use 1
"ACS758LCB-100B",// for model use 2
"ACS758LCB-100U",// for model use 3
"ACS758KCB-150B",// for model use 4
"ACS758KCB-150U",// for model use 5
"ACS758ECB-200B",// for model use 6
"ACS758ECB-200U"// for model use 7
sensitivity array is holding the sensitivy of the ACS758
current sensors. Do not change.
*/
float sensitivity[] ={
40.0,// for ACS758LCB-050B
60.0,// for ACS758LCB-050U
20.0,// for ACS758LCB-100B
40.0,// for ACS758LCB-100U
13.3,// for ACS758KCB-150B
16.7,// for ACS758KCB-150U
10.0,// for ACS758ECB-200B
20.0,// for ACS758ECB-200U
};
/*
* quiescent Output voltage is factor for VCC that appears at output
* when the current is zero.
* for Bidirectional sensor it is 0.5 x VCC
* for Unidirectional sensor it is 0.12 x VCC
* for model ACS758LCB-050B, the B at the end represents Bidirectional (polarity doesn't matter)
* for model ACS758LCB-100U, the U at the end represents Unidirectional (polarity must match)
* Do not change.
*/
float quiescent_Output_voltage [] ={
0.5,// for ACS758LCB-050B
0.12,// for ACS758LCB-050U
0.5,// for ACS758LCB-100B
0.12,// for ACS758LCB-100U
0.5,// for ACS758KCB-150B
0.12,// for ACS758KCB-150U
0.5,// for ACS758ECB-200B
0.12,// for ACS758ECB-200U
};
const float FACTOR = sensitivity[model]/1000;// set sensitivity for selected model
const float QOV = quiescent_Output_voltage [model] * VCC;// set quiescent Output voltage for selected model
float voltage;// internal variable for voltage
float cutOff = FACTOR/cutOffLimit;// convert current cut off to mV
//**** ACS758 settings ends
void setup() {
Serial.begin(9600);
// by default, we'll generate the high voltage from the 3.3v line internally! (neat!)
display.begin(SSD1306_SWITCHCAPVCC, 0x3C); // initialize with the I2C addr 0x3D (for the 128x64)
// init done
}
void loop() {
//Robojax.com ACS758 Current Sensor values start
float voltage_raw = (5.0 / 1023.0)* analogRead(VIN);// Read the voltage from sensor
voltage = voltage_raw - QOV + 0.003 ;// 0.007 is a value to make voltage zero when there is no current
float current = voltage / FACTOR;
if(abs(voltage) > cutOff ){
Serial.print("V: ");
Serial.print(voltage,3);// print voltage with 3 decimal places
Serial.print("V, I: ");
Serial.print(current,2); // print the current with 2 decimal places
Serial.println("A");
display.clearDisplay();
robojaxText("V:", 0, 0, 2, false);
String voltageS = String(voltage);// get voltage and convert it to string for display
robojaxText(voltageS +"V", 20, 0, 2, false);
robojaxText("Current:", 0, 22, 2, false);
String currentS = String(current);// get current and convert it to string for display
robojaxText(currentS +"A", 0, 40, 3, false);
display.display();
}else{
Serial.println("No Current");
display.clearDisplay();
robojaxText("No Current", 0, 0, 2, false);
display.display();
}
//Robojax.com ACS758 Current Sensor values end
delay(500);
}
/*
* robojaxText(String text, int x, int y,int size, boolean d)
* text is the text string to be printed
* x is the integer x position of text
* y is the integer y position of text
* z is the text size, 1, 2, 3 etc
* d is either "true" or "false". Not sure, use true
*/
void robojaxText(String text, int x, int y,int size, boolean d) {
display.setTextSize(size);
display.setTextColor(WHITE);
display.setCursor(x,y);
display.println(text);
if(d){
display.display();
}
delay(100);
} 
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