Diff: MaxSonar.cpp

Revision:

0:18790852a055

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MaxSonar.cpp	Tue Dec 14 12:08:17 2010 +0000
@@ -0,0 +1,141 @@
+/**
+ * @file MaxSonar.cpp
+ * @section LICENSE
+ * Copyright (c) 2010 Mustafa Ozgur Kanli.
+ *
+ * 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.
+ *
+ * @section Description
+ * Implementation of MaxSonar class.
+ */
+
+#include "mbed.h"
+#include "MaxSonar.h"
+
+MaxSonar::MaxSonar(enum MSType type, enum MSMode mode,
+                   PinName pin1, PinName pin2) {
+    
+    // Set some defaults common to all devices.
+    this->units = MS_CM;
+    this->voltage = 3.3;
+    this->ain = NULL;
+    this->rx_req = NULL;
+
+    // Save settings.
+    this->type = type;
+    this->mode = mode;
+
+    // Device specific settings.
+    switch(this->type) {
+        case MS_LV:
+            this->analog_scale = 512;
+            break;
+        
+        // @todo Add functionality.    
+        case MS_WR:
+        case MS_WRC:
+        case MS_XL:
+        case MS_XL_AE:
+        default:
+            error("MaxSonar: Currently unsupported.\n");
+            break;
+    }
+
+    // Mode specific settings.
+    switch(this->mode) {
+        case MS_ANALOG:
+            if (pin1 != NC)
+            {
+                rx_req = new DigitalOut(pin1);
+                rx_req->write(0);       // Default low to stop it ranging.
+            }
+            ain = new AnalogIn(pin2);
+            this->analog_resolution = this->voltage / this->analog_scale;
+            break;
+
+        // @todo Add functionality.            
+        case MS_SERIAL:
+        case MS_PWM:
+        default:
+            error("MaxSonar: Currently unsupported.\n");
+            break;
+    }
+}
+
+MaxSonar::~MaxSonar(void) {
+    delete ain;
+}
+
+void MaxSonar::setUnits(enum MSUnits units) {
+    this->units = units;
+}
+
+void MaxSonar::setVoltage(float voltage) {
+    this->voltage = voltage;
+    this->analog_resolution = this->voltage / this->analog_scale;
+}
+
+void MaxSonar::triggerRead(void) {
+
+    if (rx_req != NULL)
+    {
+        // Bring rx line high for 20us to perform a read. The read will
+        // be available 49ms after request.
+        rx_req->write(1);
+        wait_us(20);
+        rx_req->write(0);
+    }
+}
+
+float MaxSonar::read(void) {
+    
+    float range;
+
+    // Make the reading.
+    switch(this->mode) {
+        case MS_ANALOG:
+            //! Range value is computed in inches by default.
+            range = (this->ain->read() * this->voltage) / this->analog_resolution;
+            break;
+
+        // @todo Add functionality.            
+        case MS_SERIAL:
+        case MS_PWM:
+        default:
+            error("MaxSonar: Currently unsupported.\n");
+            break;
+    }
+    
+    // Perform conversion.
+    switch(this->units) {
+        case MS_CM:
+            range *= 2.54;
+            break;
+        
+        case MS_INCH:
+            break;
+            
+        default:
+            error("MaxSonar: Currently unsupported.\n");
+            break;
+    }
+    
+    return range;
+}
+