Joseph Bradshaw / ServoIn

Class Library for reading hobby servos and detecting invalid or disconnected channels

Dependents:   MadPulseCntrl Emaxx_Navigation Emaxx_Navigation_Dynamic_HIL Madpulse_Speed_Control_temp ... more

ServoIn Class Library

This class library uses external interrupts with timer functions to read servos pulses on mbed input pins.

ServoIn Library usage example

#include "mbed.h"
#include "ServoIn.h"

DigitalOut led1(LED1);
ServoIn servoIn1(p15);
ServoIn servoIn2(p14);
Serial pc(USBTX, USBRX); // tx, rx

int main() {    
    pc.baud(921600);            //Fast baud rate
        
    while(1) {
        led1 = 1;
        wait(0.05);
        led1 = 0;
        wait(0.05);
        
        pc.printf("servo pulse: CH1=%5dus  CH2=%5dus\r\n", servoIn1.read(), servoIn2.read());        
    }
}

Files at this revision

API Documentation at this revision

Revision 5:598ccee73ed3, committed 2017-08-14

Comitter:
jebradshaw
Date:
Mon Aug 14 14:51:20 2017 +0000
Parent:
4:379f9ab5cb4b
Commit message:
added check for valid servo pulse when greater then servo max to prevent flag check after pulse interrupt (inverted pulse measure phase)

Changed in this revision

ServoIn.cpp Show annotated file Show diff for this revision Revisions of this file 
diff -r 379f9ab5cb4b -r 598ccee73ed3 ServoIn.cpp
--- a/ServoIn.cpp	Thu Aug 04 15:46:31 2016 +0000
+++ b/ServoIn.cpp	Mon Aug 14 14:51:20 2017 +0000
@@ -48,8 +48,13 @@
     }
     else{
         servoPulse = pulseMeasure.read_us();
-        _interrupt.rise(this, &ServoIn::PulseRead);
-        _pulseFlag = 0;
+        if(servoPulse < this->servoPulseMax){
+            _interrupt.rise(this, &ServoIn::PulseRead);
+            _pulseFlag = 0;
+        }
+        else{
+            _pulseFlag = 1;  //set the pulse input flag
+        }
     }
     _validPulseTimeout.attach(this, &ServoIn::timeoutTest, 0.015); //setup interrupt for 15ms
     _t_state=0;  //re-zero t-state