Revision 0:e758665e072c, committed 2010-11-19

Comitter:

simon

Date:

Fri Nov 19 22:34:56 2010 +0000

Commit message:

Revision in new library format (extracted from old cookbook), with doxygen comments

Changed in this revision

diff -r 000000000000 -r e758665e072c SRF05.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SRF05.cpp	Fri Nov 19 22:34:56 2010 +0000
@@ -0,0 +1,61 @@
+/* mbed SRF05 Ultrasonic Rangefiner Library
+ * Copyright (c) 2007-2010, cstyles, sford
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "SRF05.h"
+#include "mbed.h"
+
+SRF05::SRF05(PinName trigger, PinName echo) 
+    : _trigger(trigger), _echo(echo) {    
+        
+    // Attach interrupts
+    _echo.rise(this, &SRF05::_rising);
+    _echo.fall(this, &SRF05::_falling);
+    _ticker.attach(this, &SRF05::_startRange, 0.1);     
+}
+  
+void SRF05::_startRange() {
+    // send a trigger pulse, 20uS long
+    _trigger = 1;
+    wait (0.000002);
+    _trigger = 0;
+}
+
+// Clear and start the timer at the begining of the echo pulse
+void SRF05::_rising(void) {
+    _timer.reset();
+    _timer.start();
+}
+
+// Stop and read the timer at the end of the pulse
+void SRF05::_falling(void) {
+    _timer.stop();
+    _dist = _timer.read_us()/58.0;
+}
+
+float SRF05::read(void) {
+    // spin until there is a good value
+    return (_dist);
+}
+
+SRF05::operator float() {
+    return read();
+}

diff -r 000000000000 -r e758665e072c SRF05.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SRF05.h	Fri Nov 19 22:34:56 2010 +0000
@@ -0,0 +1,77 @@
+/* mbed SRF05 Ultrasonic Rangefiner Library
+ * Copyright (c) 2007-2010, cstyles, sford
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MBED_SRF05_H
+#define MBED_SRF05_H
+
+#include "mbed.h"
+
+/** Library for the SRF05 Ultrasonic range finder
+ *
+ * Example:
+ * @code
+ * // Print measured distance
+ *
+ * #include "mbed.h"
+ * #include "SRF05.h"
+ *
+ * SRF05 srf(p9,p10);
+ *
+ * int main() {
+ *     while(1) {
+ *         printf("Measured : %.1f\n", srf.read());
+ *         wait(0.2);
+ *     }
+ * }
+ * @endcode
+ */
+class SRF05 {
+public:
+
+    /** Create a SRF05 object, connected to the specified pins
+     *
+     * @param trigger DigitalOut to the SRF05 trigger
+     * @param echo InterruptIn to measure the return pulse
+     */
+    SRF05(PinName trigger, PinName echo);
+    
+    /** A non-blocking function that will return the last measurement
+     *
+     * @returns floating point representation of distance in cm
+     */
+    float read();
+
+    /** A short hand way of using the read function */
+    operator float();
+    
+private :
+    DigitalOut _trigger;
+    InterruptIn _echo;
+    Timer _timer;
+    Ticker _ticker;
+    void _rising (void);
+    void _falling (void);
+    void _startRange (void);
+    float _dist;
+};
+
+#endif