Diff: PPMout.h

Revision:

0:04365c9c9994

Child:

2:4570e00696b9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PPMout.h	Fri Sep 02 11:48:31 2016 +0000
@@ -0,0 +1,106 @@
+/**
+ * @file    PPMout.h
+ * @brief   PPMout - PPM signal generator for K64F
+ * @author  Patrick Thomas
+ * @version 1.0
+ * @see
+ *
+ * Copyright (c) 2016
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef PPMOUT_H
+#define PPMOUT_H
+
+#include "mbed.h"
+
+#define PIN(n,min,max) ((n) > (max) ? max : ((n) < (min) ? (min) : (n)))
+
+// System clock
+#define BUS_CLOCK 60000000
+#define CLOCK_DIVIDER 12
+#define CMT_PPS_VAL (CLOCK_DIVIDER - 1)
+
+// Step array
+#define CHANNELS 8
+#define ARRAY_SIZE (CHANNELS + 1)
+
+// Time parameters
+#define STEPS_PER_MS (((BUS_CLOCK/CLOCK_DIVIDER)/8)/1000)
+#define GAP_LENGTH_MS 0.4
+#define FRAME_LENGTH_MS 20
+
+// PPM parameters
+#define PPM_RANGE_MS 1
+#define PPM_ZERO_MS 0.5
+
+// Derived step parameters
+#define RANGE_STEPS (PPM_RANGE_MS*STEPS_PER_MS)
+#define ZERO_STEPS (PPM_ZERO_MS*STEPS_PER_MS)
+#define GAP_STEPS (int) (GAP_LENGTH_MS*STEPS_PER_MS)
+#define TOTAL_GAP_STEPS (GAP_STEPS*ARRAY_SIZE)
+#define FRAME_STEPS (FRAME_LENGTH_MS*STEPS_PER_MS)
+#define MAX_NON_GAP_STEPS (FRAME_STEPS - TOTAL_GAP_STEPS)
+
+/** A library for producing PPM output on the K64F (pin PTD7) using the CMT (Carrier/Modulator Transmitter) module
+ *
+ * Example:
+ * @code
+ *  #include "mbed.h"
+ *  #include "PPMout.h"
+ *
+ *  PPMout myPPM;
+ *  Serial pc(USBTX, USBRX);
+ *
+ *  int main()
+ *  {
+ *      while(1) {
+ *
+ *          char buffer[128];
+ *          float f;
+ *       
+ *          pc.gets(buffer, 5);
+ *          f = (float) atof(buffer);
+ *      
+ *          myPPM.update_channel(0, f);
+ *      }
+ *  }
+ * @endcode
+ */
+
+class PPMout {
+    
+private:
+
+    static int count_array[ARRAY_SIZE];
+    static int counter;
+
+    static void CMT_IRQHandler();
+    void init();
+    void set_sync_length();
+    
+public:
+    
+    /** Create PPMout instance
+     */
+    PPMout();
+    
+    /** Update a PPM channel value
+     *  @param channel The channel to update (0-7)
+     *  @param value The new value for the channel (0-1)
+     */
+    void update_channel(int channel, float value);
+};
+
+#endif
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