Revision 2:b67f18c84c05, committed 2015-03-04

Comitter:

joe4465

Date:

Wed Mar 04 18:49:31 2015 +0000

Parent:

1:fb0ab71eb0ea

Child:

3:d13b9e50312f

Commit message:

Modified library so that the InterruptIn pin is passed into constructor instead of the InterruptIn object

Changed in this revision

--- 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

--- a/PPM.h	Thu Jan 22 18:02:33 2015 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,56 +0,0 @@
-#include "mbed.h"
-
-#ifndef PPM_H
-#define PPM_H
-
-class PPM
-{
-    public:
-        //Constructor
-        PPM(InterruptIn *ppmPin, float minimumOutput, float maximumOutput, int minimumPulseTime, int maximumPulseTime, int numberOfChannels, int throttleChannel);
-        
-    private:
-        //Interrupt
-        void SignalRise();
-        
-        //Interrupt pin
-        InterruptIn *_ppmPin;
-        
-        //Timer, times length of pulses
-        Timer _timer;
-        //Number of channels in PPM signal
-        int _numberOfChannels;
-        //Current channel
-        char _currentChannel;  
-        //Stores channel times
-        int _times[100];
-        //Stores most recent complete frame times
-        int _completeTimes[100];
-        //Keeps track of time between PPM interrupts
-        int _timeElapsed; 
-        //Minimum time of frame
-        int _minFrameTime;
-        //If the pulse time for a channel is this short, something is wrong uS
-        int _shortTime;
-        //Minimum pulse time uS
-        int _minimumPulseTime;
-        //Maximum pulse time uS
-        int _maximumPulseTime;
-        //Minimum output
-        float _minimumOutput;
-        //Maximum output
-        float _maximumOutput;
-        //Throttle channel - used for fail safe
-        int _throttleChannel;
-        
-    public:
-        //Get channel data
-        void GetChannelData(float * channelData);
-        
-    private:
-        float Map(float input, float inputMin, float inputMax, float outputMin, float outputMax);
-};
-
-#endif
-
-

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Ppm.cpp	Wed Mar 04 18:49:31 2015 +0000
@@ -0,0 +1,103 @@
+#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(PinName pin, float minimumOutput, float maximumOutput, int minimumPulseTime, int maximumPulseTime, int numberOfChannels, int throttleChannel) 
+{    
+    //Assign local variables passed into constructor
+    _ppmPin = new InterruptIn(pin);
+    _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

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Ppm.h	Wed Mar 04 18:49:31 2015 +0000
@@ -0,0 +1,56 @@
+#include "mbed.h"
+
+#ifndef Ppm_H
+#define Ppm_H
+
+class Ppm
+{
+    public:
+        //Constructor
+        Ppm(PinName pin, float minimumOutput, float maximumOutput, int minimumPulseTime, int maximumPulseTime, int numberOfChannels, int throttleChannel);
+        
+    private:
+        //Interrupt
+        void SignalRise();
+        
+        //Interrupt pin
+        InterruptIn *_ppmPin;
+        
+        //Timer, times length of pulses
+        Timer _timer;
+        //Number of channels in Ppm signal
+        int _numberOfChannels;
+        //Current channel
+        char _currentChannel;  
+        //Stores channel times
+        int _times[100];
+        //Stores most recent complete frame times
+        int _completeTimes[100];
+        //Keeps track of time between Ppm interrupts
+        int _timeElapsed; 
+        //Minimum time of frame
+        int _minFrameTime;
+        //If the pulse time for a channel is this short, something is wrong uS
+        int _shortTime;
+        //Minimum pulse time uS
+        int _minimumPulseTime;
+        //Maximum pulse time uS
+        int _maximumPulseTime;
+        //Minimum output
+        float _minimumOutput;
+        //Maximum output
+        float _maximumOutput;
+        //Throttle channel - used for fail safe
+        int _throttleChannel;
+        
+    public:
+        //Get channel data
+        void GetChannelData(float * channelData);
+        
+    private:
+        float Map(float input, float inputMin, float inputMax, float outputMin, float outputMax);
+};
+
+#endif
+
+