EmbeddedUser: Arduino Light Meter with photo resistor and OLED display

Arduino Light Meter with photo resistor and OLED display

This video show how to make an Arduino Light Meter using an Photoresistor or Light depended resistor(LDR). A 128X64 i2c Oled ssd1306 display is used to display the light intensity in percentage numeral and bar. I used an Arduino UNO 3.3V clone which uses Atmega328P.

Photo resistors are cheap and easily available on Ebay, Bangood, Sparkfun etc. Library used U8Glib: Installed directly from the Library Manager in Arduino IDE. Connect the photoresistor or LDR between 3.3V and A0 analog input pin of Arduino. Also connect an 12K or 10K resistor between A0 and ground pin of Arduino. The OLED display VCC is connected to 3.3V of Arduino. Gnd to Gnd of Arduino. SDA of OLED to SDA or Arduino, SCL of OLED to SCL of Arduino.

https://www.youtube.com/embed/47cdiDrc0xk

Light Meter code: Arduino Code download/copy the code in the box below to a file and save with .ino extension.

https://gist.github.com/embeddeduser/feab7144aceeabb6a9aa4e5862b92c75

// Light meter
// 12K resistor connected between A0 pin and GND
// Photoresistor connected between A0 and VCC 3.3V

#include "U8glib.h"

U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_NO_ACK);  // Display which does not send AC
//U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_NONE|U8G_I2C_OPT_DEV_0);  // I2C / TWI
//U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_DEV_0|U8G_I2C_OPT_NO_ACK|U8G_I2C_OPT_FAST); // Fast I2C / TWI
//U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_NO_ACK);  // Display which does not send AC
int sensorValue = 0;
unsigned int curOutputValue = 0;
unsigned int lastOutputValue;

void setup(void)
{
  Serial.begin(9600);
  lastOutputValue = ~curOutputValue;

  // assign default color value
  if (u8g.getMode() == U8G_MODE_R3G3B2)
  {
    u8g.setColorIndex(255);     // white
  }
  else if (u8g.getMode() == U8G_MODE_GRAY2BIT)
  {
    u8g.setColorIndex(3);         // max intensity
  }
  else if (u8g.getMode() == U8G_MODE_BW)
  {
    u8g.setColorIndex(1);         // pixel on
  }
  else if (u8g.getMode() == U8G_MODE_HICOLOR)
  {
    u8g.setHiColorByRGB(255, 255, 255);
  }
}
void LightMeter(uint16_t percentLight)
{
  u8g.setFont(u8g_font_fub17);
  u8g.setFontRefHeightExtendedText();
  u8g.setDefaultForegroundColor();
  u8g.setFontPosTop();
  u8g.drawStr(4, 0, "Light %");
  u8g.drawStr(4, 20, "Meter");
  u8g.drawFrame(4, 40, 122, 24);

  u8g.drawBox(8, 44, (114 * percentLight / 100), 16);

  //
  if (percentLight > 99)
  {
    u8g.setPrintPos(90, 15);
  }
  else
  {
    u8g.setPrintPos(100, 15);
  }

  u8g.print(percentLight);
}
void loop(void)
{
  sensorValue = analogRead(A0);
  Serial.print("input :");
  Serial.println(sensorValue);
// map input values between 0 t0 100%
  curOutputValue = map(sensorValue, 0, 690, 0, 100);

  if (curOutputValue > 100)
  {
    curOutputValue = 100;
  }

  if (lastOutputValue == curOutputValue)
  {
    lastOutputValue = curOutputValue;
    u8g.firstPage();

    do
    {
      LightMeter(curOutputValue);
    }
    while (u8g.nextPage());
  }

}

Follow me on Twitter : https://twitter.com/embedded_user

 
Previous Videos: 
How to connect 128X64 i2c Oled display to Arduino:
Nokia 5110 graphical lcd Demo using Arduino
Controlling RGB LEDS with Arduino and TLC5940

Subscribe to my channel
https://www.youtube.com/channel/UCqJym4fsMaT1CZ2i6GxWURQ

EmbeddedUser

Sunday, October 23, 2016

Arduino Light Meter with photo resistor and OLED display

No comments:

Post a Comment

Total Pageviews

About Me

Search This Blog

Sunday, October 23, 2016

Arduino Light Meter with photo resistor and OLED display

No comments:

Post a Comment

Total Pageviews

About Me

Subscribe To

Search This Blog