University of Plymouth - Stages 1, 2 and 3 / Mbed OS Task433Solution

Important changes to repositories hosted on mbed.com

Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.

To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.

It is also possible to export all your personal repositories from the account settings page.

Fork of Task433Solution by Nicholas Outram

main.cpp@0:fa5ec79b26fb, 2015-09-24 (annotated)

Committer:
noutram
Date:
Thu Sep 24 12:30:19 2015 +0000
Revision:
0:fa5ec79b26fb
Child:
3:3ab4c38cc96c
Initial version 24-09-2015

Who changed what in which revision?

UserRevisionLine numberNew contents of line
noutram 0:fa5ec79b26fb 1 #include "mbed.h"
noutram 0:fa5ec79b26fb 2
noutram 0:fa5ec79b26fb 3 //Constants
noutram 0:fa5ec79b26fb 4 #define N 10
noutram 0:fa5ec79b26fb 5
noutram 0:fa5ec79b26fb 6 //Global objects
noutram 0:fa5ec79b26fb 7 Serial pc(USBTX, USBRX);
noutram 0:fa5ec79b26fb 8
noutram 0:fa5ec79b26fb 9 BusOut binaryOutput(D5, D6, D7);
noutram 0:fa5ec79b26fb 10 AnalogIn POT_ADC_In(A0);
noutram 0:fa5ec79b26fb 11 AnalogIn LDR_ADC_In(A1);
noutram 0:fa5ec79b26fb 12
noutram 0:fa5ec79b26fb 13 float xPOT[N]; //Aray of potentiometer samples
noutram 0:fa5ec79b26fb 14 float xLDR[N]; //Aray of LDR samples
noutram 0:fa5ec79b26fb 15
noutram 0:fa5ec79b26fb 16 //Main function
noutram 0:fa5ec79b26fb 17 int main()
noutram 0:fa5ec79b26fb 18 {
noutram 0:fa5ec79b26fb 19
noutram 0:fa5ec79b26fb 20 //Set baud rate to 115200
noutram 0:fa5ec79b26fb 21 pc.baud(115200);
noutram 0:fa5ec79b26fb 22
noutram 0:fa5ec79b26fb 23 //Print header
noutram 0:fa5ec79b26fb 24 pc.printf("POT,LDR,avPOT, acLDR\n\n");
noutram 0:fa5ec79b26fb 25
noutram 0:fa5ec79b26fb 26 while(1) {
noutram 0:fa5ec79b26fb 27
noutram 0:fa5ec79b26fb 28 //Move the samples in both arrays to the right
noutram 0:fa5ec79b26fb 29 for (unsigned int n=(N-1); n>0; n--) {
noutram 0:fa5ec79b26fb 30 xPOT[n] = xPOT[n-1];
noutram 0:fa5ec79b26fb 31 xLDR[n] = xLDR[n-1];
noutram 0:fa5ec79b26fb 32 }
noutram 0:fa5ec79b26fb 33
noutram 0:fa5ec79b26fb 34 //Insert the new sample at position 0
noutram 0:fa5ec79b26fb 35 xPOT[0] = POT_ADC_In;
noutram 0:fa5ec79b26fb 36 xLDR[0] = LDR_ADC_In;
noutram 0:fa5ec79b26fb 37
noutram 0:fa5ec79b26fb 38 //Calculate average for POT
noutram 0:fa5ec79b26fb 39 float fSum = 0.0;
noutram 0:fa5ec79b26fb 40 for (unsigned int n=0; n<N; n++) {
noutram 0:fa5ec79b26fb 41 fSum += xPOT[n];
noutram 0:fa5ec79b26fb 42 }
noutram 0:fa5ec79b26fb 43 float fPOTAverage = fSum / (float)N;
noutram 0:fa5ec79b26fb 44
noutram 0:fa5ec79b26fb 45 //Calculate average for LDR
noutram 0:fa5ec79b26fb 46 fSum = 0.0;
noutram 0:fa5ec79b26fb 47 for (unsigned int n=0; n<N; n++) {
noutram 0:fa5ec79b26fb 48 fSum += xLDR[n];
noutram 0:fa5ec79b26fb 49 }
noutram 0:fa5ec79b26fb 50 float fLDRAverage = fSum / (float)N;
noutram 0:fa5ec79b26fb 51
noutram 0:fa5ec79b26fb 52 //Write to terminal via Serial interface
noutram 0:fa5ec79b26fb 53 pc.printf("%6.4f,%6.4f,%6.4f,%6.4f\n", xPOT[N/2], xLDR[N/2], fPOTAverage, fLDRAverage);
noutram 0:fa5ec79b26fb 54
noutram 0:fa5ec79b26fb 55 //Check the threshold
noutram 0:fa5ec79b26fb 56 if (fLDRAverage > fPOTAverage) {
noutram 0:fa5ec79b26fb 57 binaryOutput = 0; //Binary 000
noutram 0:fa5ec79b26fb 58 } else {
noutram 0:fa5ec79b26fb 59 binaryOutput = 7; //Binary 111
noutram 0:fa5ec79b26fb 60 }
noutram 0:fa5ec79b26fb 61
noutram 0:fa5ec79b26fb 62 //Wait 1/100th second
noutram 0:fa5ec79b26fb 63 wait(0.01);
noutram 0:fa5ec79b26fb 64
noutram 0:fa5ec79b26fb 65
noutram 0:fa5ec79b26fb 66 } //end while(1)
noutram 0:fa5ec79b26fb 67 } //end main