Port to Teensy 3.0 & 3.1

PaulStoffregen · Jun 6, 2014 · 02fd4f6 · 02fd4f6
1 parent 7639683
commit 02fd4f6
Show file tree

Hide file tree

Showing 6 changed files with 493 additions and 243 deletions.
diff --git a/FreqMeasure.cpp b/FreqMeasure.cpp
@@ -2,7 +2,7 @@
  * http://www.pjrc.com/teensy/td_libs_FreqMeasure.html
  * Copyright (c) 2011 PJRC.COM, LLC - Paul Stoffregen <paul@pjrc.com>
  *
- * Version 1.0
+ * Version 1.1
  * 
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -24,7 +24,7 @@
  */
 
 #include "FreqMeasure.h"
-#include "util/capture.h"
+#include "util/FreqMeasureCapture.h"
 
 #define FREQMEASURE_BUFFER_LEN 12
 static volatile uint32_t buffer_value[FREQMEASURE_BUFFER_LEN];
@@ -69,11 +69,21 @@ uint32_t FreqMeasureClass::read(void)
 	return value;
 }
 
+float FreqMeasureClass::countToFrequency(uint32_t count)
+{
+#if defined(__AVR__)
+	return (float)F_CPU / (float)count;
+#elif defined(__arm__) && defined(TEENSYDUINO)
+	return (float)F_BUS / (float)count;
+#endif
+}
+
 void FreqMeasureClass::end(void)
 {
 	capture_shutdown();
 }
 
+#if defined(__AVR__)
 
 ISR(TIMER_OVERFLOW_VECTOR)
 {
@@ -110,6 +120,40 @@ ISR(TIMER_CAPTURE_VECTOR)
 	}
 }
 
+#elif defined(__arm__) && defined(TEENSYDUINO)
+
+void FTM_ISR_NAME (void)
+{
+	uint32_t capture, period, i;
+	bool inc = false;
+
+	if (capture_overflow()) {
+		capture_overflow_reset();
+		capture_msw++;
+		inc = true;
+	}
+	if (capture_event()) {
+		capture = capture_read();
+		if (capture <= 0xE000 || !inc) {
+			capture |= (capture_msw << 16);
+		} else {
+			capture |= ((capture_msw - 1) << 16);
+		}
+		// compute the waveform period
+		period = capture - capture_previous;
+		capture_previous = capture;
+		// store it into the buffer
+		i = buffer_head + 1;
+		if (i >= FREQMEASURE_BUFFER_LEN) i = 0;
+		if (i != buffer_tail) {
+			buffer_value[i] = period;
+			buffer_head = i;
+		}
+	}
+}
+
+
+#endif
 
 FreqMeasureClass FreqMeasure;
 
diff --git a/FreqMeasure.h b/FreqMeasure.h
@@ -1,13 +1,14 @@
 #ifndef FreqMeasure_h
 #define FreqMeasure_h
 
-#include <inttypes.h>
+#include <Arduino.h>
 
 class FreqMeasureClass {
 public:
 	static void begin(void);
 	static uint8_t available(void);
 	static uint32_t read(void);
+	static float countToFrequency(uint32_t count);
 	static void end(void);
 };
 

diff --git a/examples/LCD_Output/LCD_Output.pde b/examples/LCD_Output/LCD_Output.pde
@@ -24,7 +24,7 @@ void loop() {
     sum = sum + FreqMeasure.read();
     count = count + 1;
     if (count > 30) {
-      double frequency = F_CPU / (sum / count);
+      float frequency = FreqMeasure.countToFrequency(sum / count);
       lcd.setCursor(0, 1);
       lcd.print(frequency);
       lcd.print("       ");

diff --git a/examples/Serial_Output/Serial_Output.pde b/examples/Serial_Output/Serial_Output.pde
@@ -19,7 +19,7 @@ void loop() {
     sum = sum + FreqMeasure.read();
     count = count + 1;
     if (count > 30) {
-      double frequency = F_CPU / (sum / count);
+      float frequency = FreqMeasure.countToFrequency(sum / count);
       Serial.println(frequency);
       sum = 0;
       count = 0;