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main.cpp
- Committer:
- 10782824
- Date:
- 2020-12-04
- Revision:
- 0:339d1e10c98b
File content as of revision 0:339d1e10c98b:
/* mbed Microcontroller Library
* Copyright (c) 2019 ARM Limited
* SPDX-License-Identifier: Apache-2.0
*/
#include "mbed.h"
#include "platform/mbed_thread.h"
#include "stdio.h"
/* Reference resistor in series with the thermistor is of 10 KOhm */
#define R_REFERENCE (float)(10000)
/* Beta constant of this thermistor is 3380 Kelvin. See the thermistor
(NCP18XH103F03RB) data sheet for more details. */
#define B_CONSTANT (float)(3380)
/* Resistance of the thermistor is 10K at 25 degrees C (from data sheet)
Therefore R0 = 10000 Ohm, and T0 = 298.15 Kelvin, which gives
R_INFINITY = R0 e^(-B_CONSTANT / T0) = 0.1192855 */
#define R_INFINITY (float)(0.1192855)
/* Zero Kelvin in degree C */
#define ABSOLUTE_ZERO (float)(-273.15)
//static DigitalIn thermVDD(P10_0); // if wing is detached and powered from 3.3v
//static DigitalIn thermGND(P10_3); // don't need to control power to thermistor
// Blinking rate in milliseconds
#define BLINKING_RATE_MS 500
// #define SW2 P0_4
// #define SW3 P12_3
char buffer[80];
/* prototype of function */
void displayAt( int x, int y, char *buffer );
int main()
{
// Initialise the digital pin LED1 as an output
// DigitalOut led(LED1);
// DigitalIn pushButton(SW2, PullUp);
AnalogIn vTherm(P10_1); //Input pin of Thermister potential divider
AnalogIn lightLevel(P10_4); //
DigitalOut redLed2 (P10_5);
DigitalOut greenLed (P10_0);
DigitalOut yellowLed (P0_5);
DigitalIn switch3 (P12_3);
AnalogIn pot (P10_2);
printf("\033[2J\033[H"); // clear screen and move the cursor to 0, 0
printf("\033[?25l"); // Turn off visible cursor
printf("Environmental Control System");
// printf( "\033[34m" );
fflush(stdout); // send the codes to the terminal
while (true) {
if (switch3 == 1)
redLed2 = !redLed2;
float potValue = pot.read();
if (potValue < 0.3)
greenLed = !greenLed;
if (potValue > 0.7)
yellowLed = !yellowLed;
// thread_sleep_for(BLINKING_RATE_MS);
/* if (pushButton == 0) {
led = !led;
// read thermistor Voltage
float refVoltage = vTherm.read() * 2.4; // Range of ADC 0->2*Vref
float refCurrent = refVoltage / 10000.0; // 10k Reference Resistor
float thermVoltage = 3.3 - refVoltage; // Assume supply voltage is 3.3v
float thermResistance = thermVoltage / refCurrent;
float logrT = (float32_t)log((float64_t)thermResistance);
// Calculate temperature from the resistance of thermistor using Steinhart-Hart Equation
float stEqn = (float32_t)((0.0009032679) + ((0.000248772) * logrT) +
((2.041094E-07) * pow((float64)logrT, (float32)3)));
float temperatureC = (float32_t)(((1.0 / stEqn) - 273.15) + 0.5);
sprintf(buffer, "Temperature is %2.1f\r\n", temperatureC);
displayAt(0, 3, buffer);
float lightPercent = ( 1 - lightLevel.read()) * 100;
sprintf( buffer, "Ambient Light is: %3.1f", lightPercent );
displayAt(1, 4, buffer);
thread_sleep_for(BLINKING_RATE_MS); */
}
}
void displayAt( int x, int y, char *buffer ) {
printf( "\033[%d;%dH%s", y, x, buffer);
fflush(stdout);
}