使用 Allegro ACS758 电流传感器配合 SSD1306 OLED 显示屏测量电流（适用于 Arduino）

/*
 * Arduino Sketch for Allegro ACS758 Current Sensor with SSD1306 OLED Display 
 * can be used with 128x64 or 128x32 OLED displays with SSD1306 chip
 * this sensor can measure current at a range of up to 200A
 * It operates with 3.3V 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 instructions 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 purposes only.
 * This code has been downloaded from https://robojax.com
 * 
 */



#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 sensitivity 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 a factor of VCC that appears at the output       
 *   when the current is zero. 
 *   For bidirectional sensors it is 0.5 x VCC
 *   For unidirectional sensors 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 the text
 * y is the integer y position of the text
 * size is the text size, 1, 2, 3 etc
 * d is either true or false.  Use true to display immediately.
 */
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);
}