Diff: MCP4661.cpp

Revision:

0:960d250e49b2

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MCP4661.cpp	Thu May 17 23:11:08 2012 +0000
@@ -0,0 +1,126 @@
+/* mbed MCP4661 DigiPot Driver Library
+ *
+ * Copyright (c) 2012, Kevin Kent
+ *
+ * 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 "MCP4661.h"
+#include "mbed.h"
+
+/*
+ Constructor, pin names for I2C and the I2C address of the device
+ */
+MCP4661::MCP4661(PinName sda, PinName scl, int addr)
+        : _i2c(sda, scl) {
+
+    _i2c.frequency(1000000);
+
+    _addr = addr;
+
+}
+
+
+int MCP4661::SetValue (int wiper, int value) {
+    int reg;
+    if (wiper == 0) {reg = MCP4661_VOL_WIPER0;}
+    if (wiper == 1) {
+        reg = MCP4661_VOL_WIPER1;
+        reg = (reg << 4 );
+    }
+    reg |= MCP4661_WR;
+    _write(reg, value);
+    return(0);
+}
+int MCP4661::SetMode (int mask, int mode) {
+    if ( (mode < 0) || (mode > 3) ) {
+        return(1);
+    } else {
+        for (int i=0 ; i < 16 ; i++ ) {
+
+            // if this matches, set the LED to the mode
+            if (mask & (0x1 << i)) {
+                SetLed(i,mode);
+            }
+        }
+    }
+    return(0);
+}
+
+
+
+/*
+ led is in the range 0-15
+ mode is inthe range 0-3
+ */
+int MCP4661::SetLed(int led, int mode) {
+
+    int reg = 0;
+    int offset = (led % 4);
+
+    printf("\nSetLed(%d,%d)\n", led, mode);
+
+    // makesure mode is within bounds
+    if ( (mode < 0) || (mode > 3) ) {
+        printf("Error : Invalid mode supplied\n");
+        return(1);
+    }
+
+    // determine which register this is,
+ 
+
+    // read the current status of the register
+    char regval = _read(reg);
+
+    // clear the two bit slice at the calculated offset
+    regval &= ~(0x3 << (2 * offset));
+
+    // now OR in the mode, shifted by 2*offset
+    regval |= (mode << (2 * offset));
+
+    // write the new value back
+    _write(reg, regval);
+
+    return(0);
+}
+
+
+
+// private functions for low level IO
+
+void MCP4661::_write(int reg, int data) {
+    char args[2];
+    args[0] = reg;
+    args[1] = data;
+    _i2c.write(_addr, args,2);
+}
+
+int MCP4661::_read(int reg) {
+    char args[2];
+    args[0] = reg;
+    _i2c.write(_addr, args, 1);
+    _i2c.read(_addr, args, 1);
+    return(args[0]);
+}
+
+
+
+
+