The MCP4922 is a 12 bit DAC. This library should provide easy access to its basic functionality.

Dependencies:   DAC

Revision:
0:4e1ee1c4d3bb
diff -r 000000000000 -r 4e1ee1c4d3bb DAC_SPI/DAC_SPI.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DAC_SPI/DAC_SPI.cpp	Wed Jul 04 01:29:05 2012 +0000
@@ -0,0 +1,39 @@
+#ifndef DAC_SPI_CPP
+#define DAC_SPI_CPP
+
+#include "DAC_SPI.h"
+/*SPI Channels */
+                          //since we only have two SPI channels, which must be shared, define them here.  
+SPI SPI_A(p5, NC, p7);    //If using with other serial devices, can pass a pointer to the serial channel.
+SPI SPI_B(p11, NC, p13);
+
+/*Initialize DAC */
+DAC_SPI::DAC_SPI(int SPIchannelNum, PinName _CS, PinName _LDAC) : CS(_CS), LDAC(_LDAC){  
+    if (SPIchannelNum ==1){
+        DACspi = &SPI_B;
+    }  
+    else{
+        DACspi = &SPI_A;
+    }
+    messageBits(16);
+}
+
+/** Manually change the SPI frequency 
+* Must be a value supported by the mbed and DAC
+*/
+void DAC_SPI::frequency(int freq){
+    (*DACspi).frequency(freq);    
+}
+
+
+//specify the number of bits used in message packets to the DAC.
+void DAC_SPI::messageBits(int bits){
+    (*DACspi).format(bits,0);
+}
+
+//select a DACnum for use with chips with multiple onboard DACs.
+void DAC_SPI::select(char DACnum){
+    DACselect=DACnum;
+}
+
+#endif //DAC_SPI_CPP
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