Jimmy Hack / DAC

A wrapper library for easy access to DACs using the SPI interface. Individual devices will receive their own libraries.

Dependents:   MAX500 MCP4922 MCP4822

DAC_SPI.h@1:679fa19d91b2, 2013-07-16 (annotated)

Committer:
JimmyTheHack
Date:
Tue Jul 16 05:52:01 2013 +0000
Revision:
1:679fa19d91b2
attempted to merge with DAC_SPI

Who changed what in which revision?

UserRevisionLine numberNew contents of line
JimmyTheHack 1:679fa19d91b2 1 #ifndef DAC_SPI_H
JimmyTheHack 1:679fa19d91b2 2 #define DAC_SPI_H
JimmyTheHack 1:679fa19d91b2 3 #include "mbed.h"
JimmyTheHack 1:679fa19d91b2 4
JimmyTheHack 1:679fa19d91b2 5 /* a basic parent library for use with DACs controlled via SPI. Individual hardware implementations will need their own libraries.
JimmyTheHack 1:679fa19d91b2 6 This provides basic initialization of common pins and provides a serial channel. Doesn't provide a lot of added functionality, but serves as an interface for the SPI library.
JimmyTheHack 1:679fa19d91b2 7 */
JimmyTheHack 1:679fa19d91b2 8 class DAC_SPI
JimmyTheHack 1:679fa19d91b2 9 {
JimmyTheHack 1:679fa19d91b2 10 public:
JimmyTheHack 1:679fa19d91b2 11 DAC_SPI(int SPIchannelNum, PinName CS, PinName LDAC);
JimmyTheHack 1:679fa19d91b2 12 virtual void select(char DACvalue); //choose the active DAC
JimmyTheHack 1:679fa19d91b2 13 virtual void write(int DACvalue) =0; //write a value to the Digital Analog Converter
JimmyTheHack 1:679fa19d91b2 14 virtual void write_mV(int millivolts) =0; //write a value to the Digital Analog Converter specified in mV (may require appropriate scaling factor)
JimmyTheHack 1:679fa19d91b2 15
JimmyTheHack 1:679fa19d91b2 16 /** Manually change the SPI frequency
JimmyTheHack 1:679fa19d91b2 17 * @param freq Desired frequency in hertz: must be a value supported by both the mbed and DAC. The MCP4922 supports frequencies to 20MHz.
JimmyTheHack 1:679fa19d91b2 18 */
JimmyTheHack 1:679fa19d91b2 19 void frequency(int freq);
JimmyTheHack 1:679fa19d91b2 20 //set the number of bits for DAC
JimmyTheHack 1:679fa19d91b2 21 void messageBits(int bits);
JimmyTheHack 1:679fa19d91b2 22 //DigitalOut SCK;
JimmyTheHack 1:679fa19d91b2 23 /** The currently selected DAC channel. 0 for DAC A, 1 for DAC B, etc*/
JimmyTheHack 1:679fa19d91b2 24 char DACselect;
JimmyTheHack 1:679fa19d91b2 25 DigitalOut CS; //serial chip select pin
JimmyTheHack 1:679fa19d91b2 26 DigitalOut LDAC; //synchronize pin to update both DACs together
JimmyTheHack 1:679fa19d91b2 27 SPI * DACspi; //SPI channel. 0 for p5-p7, 1 for p11-p13
JimmyTheHack 1:679fa19d91b2 28 };
JimmyTheHack 1:679fa19d91b2 29
JimmyTheHack 1:679fa19d91b2 30 extern SPI SPI_A; //channel A SPI (pins 5,7)
JimmyTheHack 1:679fa19d91b2 31 extern SPI SPI_B; //channel B SPI (pins 11,13)
JimmyTheHack 1:679fa19d91b2 32
JimmyTheHack 1:679fa19d91b2 33 #endif //DAC_H