Hi Guys please see attached document as I've detailed everything. Please assist as I need to complete this project urgently.
Designing a lux meter.pdf (120 KB)
What attached document?
Class assignment due tomorrow?
Read these
//Lux
double Light (int RawADC0){
double Vout=RawADC0*0.0048828125;
//int lux=500/(10*((5-Vout)/Vout));//use this equation if the LDR is in the upper part of the divider
int lux=(2500/Vout-500)/10;
return lux;
}
void setup() {
Serial.begin(115200);
}
void loop() {
Serial.println(int(Light(analogRead(0))));
delay(1000);
}
Here are the content of the Designing a lux meter.pdf to save other for download it.
Hi guys I've got the following code which I took online for the Lux meter sketch:
/*
* LDR Lux Meter
*
* This sketch calculates the lux from a voltage reading
*
* The hardware connected to Analog Pin 0 should be a voltage divider circuit between an LDR and a
* resistor (nominally 5kohm). The resistor should be connected to ground and the LDR should be
* connected to 5V. The point in between should be connected to Analog Pin 0.
* 1) Calculate voltage based on reading
* 2) Calculate resistance of LDR based on voltage
* 3) Calculate the lux that must be falling on LDR based on the resistance
*
* The lux reading is then output to an Adafruit LCD shield.
*/
#include <Wire.h>
// I2C and LCD Shield libraries
#include <Adafruit_MCP23017.h>
#include <Adafruit_RGBLCDShield.h>
// The shield uses the I2C SCL and SDA pins. On classic Arduinos
// this is Analog 4 and 5 so you can't use those for analogRead() anymore
// However, you can connect other I2C sensors to the I2C bus and share
// the I2C bus.
Adafruit_RGBLCDShield lcd = Adafruit_RGBLCDShield();
// These #defines make it easy to set the backlight color
#define RED 0x1
#define YELLOW 0x3
#define GREEN 0x2
#define TEAL 0x6
#define BLUE 0x4
#define VIOLET 0x5
#define WHITE 0x7
// These constants, define values needed for the LDR readings and ADC
#define LDR_PIN 0
#define MAX_ADC_READING 1023
#define ADC_REF_VOLTAGE 5.0
#define REF_RESISTANCE 5030 // measure this for best results
#define LUX_CALC_SCALAR 12518931
#define LUX_CALC_EXPONENT -1.405
/****/
/*
Configure the LCD to be 16 char by 2 rows.
Background is set to white.
LCD says hello and please wait.
*/
/****/
void configureLCD(void)
{
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
lcd.setBacklight(WHITE);
// Print a message to the LCD. We track how long it takes since
// this library has been optimized a bit and we're proud of it :)
//int time = millis();
lcd.print(F("Initializing!"));
delay(555);
lcd.setCursor(0,1);
lcd.print(F("Please wait..."));
//time = millis() - time;
//Serial.print("Took "); Serial.print(time); Serial.println(" ms");
delay(1000);
lcd.clear();
}
/*****/
/*
Arduino setup function (automatically called at startup)
*/
/*****/
void setup(void)
{
Serial.begin(9600);
Serial.println(F("Light Sensor Test")); Serial.println("");
/* Setup the LCD to be ready to display */
configureLCD();
/* We're ready to go! */
Serial.println(F("Sensor, LCD and SD Card are Configured."));
}
/******/
/****/
void loop(void)
{
int ldrRawData;
float resistorVoltage, ldrVoltage;
float ldrResistance;
float ldrLux;
// Perform the analog to digital conversion
ldrRawData = analogRead(LDR_PIN);
// RESISTOR VOLTAGE_CONVERSION
// Convert the raw digital data back to the voltage that was measured on the analog pin
resistorVoltage = (float)ldrRawData / MAX_ADC_READING * ADC_REF_VOLTAGE;
// voltage across the LDR is the 5V supply minus the 5k resistor voltage
ldrVoltage = ADC_REF_VOLTAGE - resistorVoltage;
// LDR_RESISTANCE_CONVERSION
// resistance that the LDR would have for that voltage
ldrResistance = ldrVoltage/resistorVoltage * REF_RESISTANCE;
// LDR_LUX
// Change the code below to the proper conversion from ldrResistance to
// ldrLux
ldrLux = LUX_CALC_SCALAR * pow(ldrResistance, LUX_CALC_EXPONENT);
// print out the results
Serial.print("LDR Raw Data : "); Serial.println(ldrRawData);
Serial.print("LDR Voltage : "); Serial.print(ldrVoltage); Serial.println(" volts");
Serial.print("LDR Resistance : "); Serial.print(ldrResistance); Serial.println(" Ohms");
Serial.print("LDR Illuminance: "); Serial.print(ldrLux); Serial.println(" lux");
// Print out the LDR Illuminance to the LCD
lcd.setCursor(0,0); // set cursor to column 0, line 1
lcd.print("LDR Lux Meter");
lcd.setCursor(0,1); // set cursor to column 0, line 2
lcd.print(ldrLux);
lcd.setCursor(7, 1); // set cursor to column 4, line 1
lcd.print(" lux");
delay(250);
}
errors received where the following:
Downloads\LuxMeterFromLDR\LuxMeterFromLDR.ino:21:31: fatal error: Adafruit_MCP23017.h: No such file or directory
#include <Adafruit_MCP23017.h>
^
compilation terminated.
exit status 1
Error compiling for board Arduino/Genuino Uno.
then I downloaded the Adafruit_MCP23017h library and this were the following errors:
libraries\Adafruit-RGB-LCD-Shield-Library-master\utility\Adafruit_MCP23017.cpp.o: In function Adafruit_MCP23017::begin(unsigned char)': C:\Program Files (x86)\Arduino\libraries\Adafruit-RGB-LCD-Shield-Library-master\utility/Adafruit_MCP23017.cpp:52: multiple definition of Adafruit_MCP23017::begin(unsigned char)'
libraries\Adafruit-MCP23017-Arduino-Library-master\Adafruit_MCP23017.cpp.o:C:\Program Files (x86)\Arduino\libraries\Adafruit-MCP23017-Arduino-Library-master/Adafruit_MCP23017.cpp:113: first defined here
libraries\Adafruit-RGB-LCD-Shield-Library-master\utility\Adafruit_MCP23017.cpp.o: In function wiresend': C:\Program Files (x86)\Arduino\libraries\Adafruit-RGB-LCD-Shield-Library-master\utility/Adafruit_MCP23017.cpp:36: multiple definition of Adafruit_MCP23017::begin()'
libraries\Adafruit-MCP23017-Arduino-Library-master\Adafruit_MCP23017.cpp.o:C:\Program Files (x86)\Arduino\libraries\Adafruit-MCP23017-Arduino-Library-master/Adafruit_MCP23017.cpp:57: first defined here
libraries\Adafruit-RGB-LCD-Shield-Library-master\utility\Adafruit_MCP23017.cpp.o: In function wiresend': C:\Program Files (x86)\Arduino\libraries\Adafruit-RGB-LCD-Shield-Library-master\utility/Adafruit_MCP23017.cpp:36: multiple definition of Adafruit_MCP23017::writeGPIOAB(unsigned int)'
libraries\Adafruit-MCP23017-Arduino-Library-master\Adafruit_MCP23017.cpp.o:C:\Program Files (x86)\Arduino\libraries\Adafruit-MCP23017-Arduino-Library-master/Adafruit_MCP23017.cpp:57: first defined here
libraries\Adafruit-RGB-LCD-Shield-Library-master\utility\Adafruit_MCP23017.cpp.o: In function wiresend': C:\Program Files (x86)\Arduino\libraries\Adafruit-RGB-LCD-Shield-Library-master\utility/Adafruit_MCP23017.cpp:36: multiple definition of Adafruit_MCP23017::pullUp(unsigned char, unsigned char)'
libraries\Adafruit-MCP23017-Arduino-Library-master\Adafruit_MCP23017.cpp.o:C:\Program Files (x86)\Arduino\libraries\Adafruit-MCP23017-Arduino-Library-master/Adafruit_MCP23017.cpp:57: first defined here
libraries\Adafruit-RGB-LCD-Shield-Library-master\utility\Adafruit_MCP23017.cpp.o: In function wiresend': C:\Program Files (x86)\Arduino\libraries\Adafruit-RGB-LCD-Shield-Library-master\utility/Adafruit_MCP23017.cpp:36: multiple definition of Adafruit_MCP23017::digitalRead(unsigned char)'
libraries\Adafruit-MCP23017-Arduino-Library-master\Adafruit_MCP23017.cpp.o:C:\Program Files (x86)\Arduino\libraries\Adafruit-MCP23017-Arduino-Library-master/Adafruit_MCP23017.cpp:57: first defined here
libraries\Adafruit-RGB-LCD-Shield-Library-master\utility\Adafruit_MCP23017.cpp.o: In function wiresend': C:\Program Files (x86)\Arduino\libraries\Adafruit-RGB-LCD-Shield-Library-master\utility/Adafruit_MCP23017.cpp:36: multiple definition of Adafruit_MCP23017::readGPIOAB()'
libraries\Adafruit-MCP23017-Arduino-Library-master\Adafruit_MCP23017.cpp.o:C:\Program Files (x86)\Arduino\libraries\Adafruit-MCP23017-Arduino-Library-master/Adafruit_MCP23017.cpp:57: first defined here
libraries\Adafruit-RGB-LCD-Shield-Library-master\utility\Adafruit_MCP23017.cpp.o: In function wiresend': C:\Program Files (x86)\Arduino\libraries\Adafruit-RGB-LCD-Shield-Library-master\utility/Adafruit_MCP23017.cpp:36: multiple definition of Adafruit_MCP23017::pinMode(unsigned char, unsigned char)'
libraries\Adafruit-MCP23017-Arduino-Library-master\Adafruit_MCP23017.cpp.o:C:\Program Files (x86)\Arduino\libraries\Adafruit-MCP23017-Arduino-Library-master/Adafruit_MCP23017.cpp:57: first defined here
libraries\Adafruit-RGB-LCD-Shield-Library-master\utility\Adafruit_MCP23017.cpp.o: In function wiresend': C:\Program Files (x86)\Arduino\libraries\Adafruit-RGB-LCD-Shield-Library-master\utility/Adafruit_MCP23017.cpp:36: multiple definition of Adafruit_MCP23017::digitalWrite(unsigned char, unsigned char)'
libraries\Adafruit-MCP23017-Arduino-Library-master\Adafruit_MCP23017.cpp.o:C:\Program Files (x86)\Arduino\libraries\Adafruit-MCP23017-Arduino-Library-master/Adafruit_MCP23017.cpp:57: first defined here
collect2.exe: error: ld returned 1 exit status
exit status 1
Error compiling for board Arduino/Genuino Uno.
Please help as I need to complete this project urgently.
hi BillHo
I'd like to check will the program work, and displace the lux readings on the LCD? I've got the following hardware components:
•1 light dependent resistor (it doesn't matter which one, you don't even need to know the part number)
•5 kilo ohm resistor
•Arduino
•2x16 LCD shield
•Breadboard
•Digital Multimeter (DMM)
•Commercial lux meter (for characterizing your LDR)
Please get back to me asap.
Hi Guys
Can you please assist regarding to the reply from Billho.
Please check if his code will work on the following hardware components:
•1 light dependent resistor (it doesn't matter which one, you don't even need to know the part number)
•5 kilo ohm resistor
•Arduino
•2x16 LCD shield
•Breadboard
•Digital Multimeter (DMM)
•Commercial lux meter (for characterizing your LDR)
Please get back to me asap