Diff: MCP4812.cpp

Revision:

0:a68207b74d7d

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MCP4812.cpp	Sat Jun 02 13:51:53 2012 +0000
@@ -0,0 +1,113 @@
+/* MCP4812 library 
+ * MCP4822 library
+ * Copyright (c) 2008-2010, Lerche
+ *
+ * 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.
+ * modified on 27.05.2012 for MCP4812 dual SPI DAC with 10 bits resolution 
+ */
+
+#include "mbed.h"
+#include "MCP4812.h"
+
+using namespace mbed;
+
+MCP4812::MCP4812(PinName mosi, PinName sclk, PinName ncs) : _spi(mosi, NC, sclk), _ncs(ncs) {
+    _init();
+}
+
+void MCP4812::_init() {
+    _spi.format(16, 0);  // Setup the SPI
+    return;
+}
+
+void MCP4812::writeA(int ValueA, int gainA) {
+    ValueA = ValueA << 2;
+    ValueA = ValueA &= 0x0FFF;
+    if (gainA == 1) {
+        ValueA = ValueA |= 0x2000; // gain 1x, 0V...2.048V (2mV step)
+        }
+    if (gainA == 2) {
+        ValueA = ValueA |= 0x0000; // gain 2x, 0V...4.096V (4mV step)
+        }
+    ValueA = ValueA |= 0x1000;      // Write to A register  
+    _ncs = 0;       // Chipselect the device.
+    _spi.write(ValueA);
+    _ncs = 1;
+    return;
+}
+
+void MCP4812::writeB(int ValueB, int gainB) {
+    ValueB = ValueB << 2;
+    ValueB = ValueB &= 0x0FFF;
+    if (gainB == 1) {
+        ValueB = ValueB |= 0x2000; // gain 1x, 0V...2.048V (2mV step)
+        }
+    if (gainB == 2) {
+        ValueB = ValueB |= 0x0000; // gain 2x, 0V...4.096V (4mV step)
+        }
+    ValueB = ValueB |= 0x9000;      // Write to B register
+    _ncs = 0;       // Chipselect the device.
+    _spi.write(ValueB);
+    _ncs = 1;
+    return;
+}
+
+void MCP4812::write(char chan, int value, int gain) {
+    value = value << 2;
+    value = value &= 0x0FFF;
+    if (gain == 1) {
+        value = value |= 0x2000; // gain 1x, 0V...2.048V (2mV step)
+        }
+    if (gain == 2) {
+        value = value |= 0x0000; // gain 2x, 0V...4.096V (4mV step)
+        }
+    switch(chan){
+        case('A'):
+            value = value |= 0x1000;
+            break; 
+        case('B'):
+            value = value |= 0x9000;
+            break;
+        case('a'):
+            value = value |= 0x1000;
+            break; 
+        case('b'):
+            value = value |= 0x9000;
+            break;
+        case(0x01):
+            value = value |= 0x1000;
+            break; 
+        case(0x02):
+            value = value |= 0x9000;
+            break;
+        default: 
+            break;        
+    }
+    _ncs = 0;
+    _spi.write(value);
+    _ncs = 1;
+    return;
+}
+
+void MCP4812::shdn() {
+    _ncs = 0;
+    _spi.write(0x0000);
+    _ncs = 1;
+    return;
+}
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