DemoBoard_RangeIndicator -

Users » chris » Code » DemoBoard_RangeIndicator

main.cpp@1:7354a0bac81a, 2009-09-22 (annotated)

User	Revision	Line number	New contents of line
chris	1:7354a0bac81a	1	#include "DemoBoard.h"
chris	0:c88750da21d0	2
chris	0:c88750da21d0	3	/*
chris	0:c88750da21d0	4	* This project used and ultrasonic range finder to blend and RGB LED from
chris	0:c88750da21d0	5	* green to yellow to red as the ranged object gets closer
chris	0:c88750da21d0	6	*/
chris	0:c88750da21d0	7
chris	0:c88750da21d0	8	int main() {
chris	0:c88750da21d0	9
chris	0:c88750da21d0	10	while (1) {
chris	0:c88750da21d0	11
chris	0:c88750da21d0	12	// Take a reading from the Ultrasonic Range Finder
chris	0:c88750da21d0	13	float d = srf;
chris	0:c88750da21d0	14
chris	0:c88750da21d0	15	// Scale and trim the number so it approaches 0.0 at a long range
chris	0:c88750da21d0	16	// and approaches 1.0 as the range gets closer
chris	0:c88750da21d0	17	float normalised = (2.0/d) - 0.02;
chris	0:c88750da21d0	18
chris	0:c88750da21d0	19	// Set the red component to get brighter the closer the range
chris	1:7354a0bac81a	20	rgb.red(normalised);
chris	0:c88750da21d0	21
chris	0:c88750da21d0	22	// Set the red component to get brighter the further the range
chris	1:7354a0bac81a	23	rgb.green(1.0-normalised);
chris	0:c88750da21d0	24
chris	0:c88750da21d0	25	// For completeness, print the measured range
chris	0:c88750da21d0	26	pc.printf("Range is %.1f cm\n",(float)srf);
chris	0:c88750da21d0	27	wait (0.2);
chris	0:c88750da21d0	28
chris	0:c88750da21d0	29	}
chris	0:c88750da21d0	30
chris	0:c88750da21d0	31	}
chris	0:c88750da21d0	32
chris	0:c88750da21d0	33