Joseph Roberts / LidarLitePwm

Library for the LidarLite, gets distance in cm using the pwm output

Dependents:   LidarLite_test

Fork of MaxbotixDriver by Daniel Casner

LidarLitePwm.cpp@2:be66a4cd86c0, 2015-03-18 (annotated)

Committer:
joe4465
Date:
Wed Mar 18 09:17:13 2015 +0000
Revision:
2:be66a4cd86c0
Parent:
1:32f0a592b9e5
Child:
3:0b1f4404cb21
V1.1 Internal timer

Who changed what in which revision?

UserRevisionLine numberNew contents of line
joe4465 1:32f0a592b9e5 1 #include "LidarLitePwm.h"
joe4465 1:32f0a592b9e5 2
joe4465 2:be66a4cd86c0 3 LidarLitePwm::LidarLitePwm(PinName pin) : _interrupt(pin)
joe4465 1:32f0a592b9e5 4 {
joe4465 2:be66a4cd86c0 5 _pulseStartTime = 0;
joe4465 2:be66a4cd86c0 6 _range = 0;
joe4465 2:be66a4cd86c0 7 _timer.start();
joe4465 1:32f0a592b9e5 8 _interrupt.rise(this, &LidarLitePwm::pulseStart);
joe4465 1:32f0a592b9e5 9 _interrupt.fall(this, &LidarLitePwm::pulseStop);
joe4465 1:32f0a592b9e5 10 }
joe4465 1:32f0a592b9e5 11
joe4465 2:be66a4cd86c0 12 LidarLitePwm::~LidarLitePwm(){}
joe4465 2:be66a4cd86c0 13
joe4465 1:32f0a592b9e5 14 int LidarLitePwm::read()
joe4465 1:32f0a592b9e5 15 {
joe4465 1:32f0a592b9e5 16 return _range;
joe4465 1:32f0a592b9e5 17 }
joe4465 1:32f0a592b9e5 18
joe4465 1:32f0a592b9e5 19 LidarLitePwm::operator int()
joe4465 1:32f0a592b9e5 20 {
joe4465 1:32f0a592b9e5 21 return read();
joe4465 1:32f0a592b9e5 22 }
joe4465 1:32f0a592b9e5 23
joe4465 1:32f0a592b9e5 24 void LidarLitePwm::pulseStart()
joe4465 1:32f0a592b9e5 25 {
joe4465 1:32f0a592b9e5 26 _pulseStartTime = _timer.read_us();
joe4465 1:32f0a592b9e5 27 }
joe4465 1:32f0a592b9e5 28
joe4465 1:32f0a592b9e5 29 void LidarLitePwm::pulseStop()
joe4465 1:32f0a592b9e5 30 {
joe4465 1:32f0a592b9e5 31 int endTime = _timer.read_us();
joe4465 1:32f0a592b9e5 32 if (endTime < _pulseStartTime) return; // Escape if there's been a roll over
joe4465 1:32f0a592b9e5 33 _range = (endTime - _pulseStartTime) / 10; // 10uS per CM
joe4465 1:32f0a592b9e5 34 }