The MCP4922 is a 12 bit DAC. This library should provide easy access to its basic functionality.
Diff: DAC_SPI/DAC_SPI.cpp
- 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 \ No newline at end of file