Alain Pegatoquet / Mbed 2 deprecated chrono_ER1

Chrono pour mesurer vitesse pour 1 tour (capteur analogique)

Dependencies:   mbed

main.cpp@1:d5f22105a691, 2017-11-28 (annotated)

Committer:
alainpegatoquet
Date:
Tue Nov 28 11:35:11 2017 +0000
Revision:
1:d5f22105a691
Parent:
0:cf0fbe1e01d4 
Chrono valid? (capteur a 20 cm distance de la ligne)

Who changed what in which revision?

UserRevisionLine numberNew contents of line
alainpegatoquet 0:cf0fbe1e01d4 1 #include "mbed.h"
alainpegatoquet 1:d5f22105a691 2 #define DIST 15
alainpegatoquet 1:d5f22105a691 3 #define DEBUG 0
alainpegatoquet 0:cf0fbe1e01d4 4
alainpegatoquet 0:cf0fbe1e01d4 5 // Global variables
alainpegatoquet 0:cf0fbe1e01d4 6 Serial pc(USBTX, USBRX);
alainpegatoquet 0:cf0fbe1e01d4 7 AnalogIn Ain(A3);
alainpegatoquet 0:cf0fbe1e01d4 8 Timer timer1;
alainpegatoquet 0:cf0fbe1e01d4 9
alainpegatoquet 0:cf0fbe1e01d4 10 float IrSensor;
alainpegatoquet 1:d5f22105a691 11 float dist_new = 0.0;
alainpegatoquet 1:d5f22105a691 12 float dist_old = 0.0;
alainpegatoquet 1:d5f22105a691 13 int elapsed_time = 0;
alainpegatoquet 0:cf0fbe1e01d4 14 // Prototype
alainpegatoquet 0:cf0fbe1e01d4 15 float distance(float);
alainpegatoquet 0:cf0fbe1e01d4 16
alainpegatoquet 0:cf0fbe1e01d4 17 // main function
alainpegatoquet 0:cf0fbe1e01d4 18 int main(void)
alainpegatoquet 0:cf0fbe1e01d4 19 {
alainpegatoquet 0:cf0fbe1e01d4 20 pc.printf("Debut du programme...\n");
alainpegatoquet 1:d5f22105a691 21 timer1.start();
alainpegatoquet 0:cf0fbe1e01d4 22
alainpegatoquet 0:cf0fbe1e01d4 23 while(1) {
alainpegatoquet 0:cf0fbe1e01d4 24 IrSensor=Ain.read(); // IrSensor belongs to [0.0; 1.0]
alainpegatoquet 1:d5f22105a691 25 //pc.printf("Distance en cm : %.1f \n\r",distance(IrSensor*3.3));
alainpegatoquet 1:d5f22105a691 26 #if DEBUG
alainpegatoquet 0:cf0fbe1e01d4 27 pc.printf("%f \n\r",IrSensor*3.3); // Output voltage from 0 to 3.3V
alainpegatoquet 0:cf0fbe1e01d4 28 pc.printf("Distance en cm : %.1f \n\r",distance(IrSensor*3.3));
alainpegatoquet 1:d5f22105a691 29 #endif
alainpegatoquet 1:d5f22105a691 30 dist_old = dist_new;
alainpegatoquet 1:d5f22105a691 31 dist_new = distance(IrSensor*3.3);
alainpegatoquet 1:d5f22105a691 32 if ((dist_old > 40) && ((dist_new> 0) && (dist_new < 30)))
alainpegatoquet 1:d5f22105a691 33 {
alainpegatoquet 1:d5f22105a691 34 elapsed_time = timer1.read_ms();
alainpegatoquet 1:d5f22105a691 35 timer1.reset();
alainpegatoquet 1:d5f22105a691 36 pc.printf("************* %2.2f sec *************\r\n",(float)elapsed_time/1000.0);
alainpegatoquet 1:d5f22105a691 37 wait_ms(1000);
alainpegatoquet 1:d5f22105a691 38 }
alainpegatoquet 1:d5f22105a691 39 wait(0.1);
alainpegatoquet 1:d5f22105a691 40 float val = timer1.read_ms()/1000.0;
alainpegatoquet 1:d5f22105a691 41 pc.printf("%3.2f sec\r",val);
alainpegatoquet 1:d5f22105a691 42
alainpegatoquet 0:cf0fbe1e01d4 43 }
alainpegatoquet 1:d5f22105a691 44 timer1.stop();
alainpegatoquet 0:cf0fbe1e01d4 45 }
alainpegatoquet 0:cf0fbe1e01d4 46
alainpegatoquet 0:cf0fbe1e01d4 47 // Calcul de la distance
alainpegatoquet 0:cf0fbe1e01d4 48 // Entre 20 et 80cm, on peut approximer la distance avec r=24/(V-0,1)
alainpegatoquet 0:cf0fbe1e01d4 49 // r = distance en cm
alainpegatoquet 0:cf0fbe1e01d4 50 // V = tension lue
alainpegatoquet 0:cf0fbe1e01d4 51 float distance(float tension)
alainpegatoquet 0:cf0fbe1e01d4 52 {
alainpegatoquet 0:cf0fbe1e01d4 53 return(24.0/(tension - 0.1));
alainpegatoquet 0:cf0fbe1e01d4 54 }
alainpegatoquet 0:cf0fbe1e01d4 55