Diff: PPM.cpp

Revision:

2:b67f18c84c05

Parent:

1:fb0ab71eb0ea

Child:

3:d13b9e50312f

diff -r fb0ab71eb0ea -r b67f18c84c05 PPM.cpp
--- a/PPM.cpp	Thu Jan 22 18:02:33 2015 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,103 +0,0 @@
-#include "PPM.h"    
-
-//PPM reader by Joe Roberts, based on work by John Wolter
-//This program takes the PPM Signal (Pulse Position Modulation) from your RC transmitter and outputs the data between the min/max outputs passed into the constructor
-//See 
-PPM::PPM(InterruptIn *ppmPin, float minimumOutput, float maximumOutput, int minimumPulseTime, int maximumPulseTime, int numberOfChannels, int throttleChannel) 
-{    
-    //Assign local variables passed into constructor
-    _ppmPin = ppmPin;
-    _minimumOutput = minimumOutput;
-    _maximumOutput = maximumOutput;
-    _minimumPulseTime = minimumPulseTime;
-    _maximumPulseTime = maximumPulseTime;
-    _numberOfChannels = numberOfChannels;
-    _throttleChannel = throttleChannel;
-        
-    //Set other variables
-    _currentChannel = 0;  
-    _timeElapsed = 0; 
-    _minFrameTime = 6000;
-    _shortTime = 800;
-
-    //Initialise arrays
-    for(int i = 0; i < _numberOfChannels; i++)
-    {
-        _times[i] = 0;
-        _completeTimes[i] = 0;
-    }
-    
-    //Assign interrupt
-    _ppmPin->mode (PullUp);
-    _ppmPin->rise (this, &PPM::SignalRise);
-
-    //Start timer
-    _timer.start();
-}
-   
-//Here is where all the work decoding the PPM signal takes place
-void PPM::SignalRise()
-{
-    //Get the time taken since the last interrupt
-    _timeElapsed = _timer.read_us();
-    
-    //If time is less than _shortTime then the channel timing is too short - ignore
-    if (_timeElapsed < _shortTime) return;
-    
-    //Disable the interrupt
-    _ppmPin->rise(NULL);
-
-    //Reset the timer
-    _timer.reset();
-    
-    //Check for a new frame signal, if before start of new frame then its a glitch - start a new frame
-    if ((_timeElapsed > _minFrameTime) && (_currentChannel != 0)) _currentChannel = 0;
-    
-    //Check for a new frame signal, if it is the start of a new frame then start new frame
-    if ((_timeElapsed > _minFrameTime ) && (_currentChannel == 0))
-    {
-        //Assign interrupt
-        _ppmPin->rise (this, &PPM::SignalRise);
-        return;
-    }
- 
-    //Save the time to the times array
-    _times[_currentChannel] = _timeElapsed;
-    _currentChannel++;
-    
-    //Check for a complete frame
-    if (_currentChannel == _numberOfChannels)
-    {
-        //Set channel iterator to 0
-        _currentChannel = 0;
-        //Copy times array to complete times array
-        memcpy(_completeTimes, _times, sizeof(_times));
-    }
-
-    //Assign interrupt
-    _ppmPin->rise(this, &PPM::SignalRise);
-    return;
-}
-
-//Place mapped channel data into the passed in array
-void PPM::GetChannelData(float * channelData)
-{
-    //Iterate over the channel times array
-    for(int i = 0; i < _numberOfChannels; i++)
-    {
-        //Check the transmitter is still connected by checking the thottle
-        if((i == _throttleChannel - 1) && (_completeTimes[i] < _minimumPulseTime)) channelData[i] = -1;
-        else
-        {
-            //Map the channel times to value between the channel min and channel max
-            channelData[i] = Map(_completeTimes[i] ,_minimumPulseTime, _maximumPulseTime, _minimumOutput, _maximumOutput);
-        }
-    }
-    
-    return; 
-}
-
-float PPM::Map(float input, float inputMin, float inputMax, float outputMin, float outputMax)
-{
-    return (input - inputMin) * (outputMax - outputMin) / (inputMax - inputMin) + outputMin;
-}
\ No newline at end of file