Page 229 - ARM Based Microcontroller Projects Using MBED

8.25 PROJECT 21—CHANGING LED FLASHING RATE WITH A POTENTIOMETER 215
/*************************************************************************

LIGHT LEVEL METER
=================
This is a light level meter project. A light dependent resistor is
connected to one of the analog inputs of the development board. The
project displays the light level in lux on the PC screen.
Author: Dogan Ibrahim
Date : August 2018
File : LDR
**************************************************************************/
#include "mbed.h"
Serial MyPC(USBTX, USBRX);
AnalogIn LDR(PA_0);

// Clear the screen
//
void clrscr()
{
char clrscr[] = {0x1B, '[', '2' , 'J',0};
MyPC.printf(clrscr);
}
//
// Home the cursor
//
void homescr()
{
char homescr[] = {0x1B, '[' , 'H' , 0};
MyPC.printf(homescr);
}
//
// Goto specified line and column
//
void gotoscr(int line, int column)
{
char scr[] = {0x1B, '[', 0x00, ';' ,0x00, 'H', 0};
scr[2] = line;
scr[4] = column;
MyPC.printf(scr);
}

int main()
{
double mV, R, lux;

clrscr(); // Clear the screen
homescr(); // Home the cursor
MyPC.printf("\n\rLIGHT LEVEL METER"); // Display heading
MyPC.printf("\n\r=================");
FIG. 8.83 Program listing.
(Continued)