Mirror
/
ardupilot
mirror of https://github.com/ArduPilot/ardupilot
5
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

AP_RPM: define a minimum acceptable period for PWM input 

this will reject very short periods as invalid. This helps somewhat
with noise on the line
This commit is contained in:
Andrew Tridgell 2015-08-08 19:08:43 +10:00
parent 80ad9aa605
commit 129f33c26d
1 changed files with 7 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
libraries/AP_RPM/RPM_PX4_PWM.cpp
View File

@ -34,6 +34,12 @@
extern const AP_HAL::HAL& hal;
/*
don't accept periods below 100us as it is probably ringing of the
signal. It would represent 600k RPM
*/
#define RPM_MIN_PERIOD_US 100
/*
open the sensor in constructor
*/
@ -79,7 +85,7 @@ void AP_RPM_PX4_PWM::update(void)
while (::read(_fd, &pwm, sizeof(pwm)) == sizeof(pwm)) {
// the px4 pwm_input driver reports the period in microseconds
if (pwm.period > 0) {
if (pwm.period > RPM_MIN_PERIOD_US) {
sum += (1.0e6f * 60) / pwm.period;
count++;
}