decarvalho adelino / Mcp4921Lib

Library to control the 12 Bits Analog Digital Converter MCP4921

Mcp4921.h@1:1352606a60c6, 2013-11-17 (annotated)

Committer:
adelino
Date:
Sun Nov 17 13:34:18 2013 +0000
Revision:
1:1352606a60c6
Parent:
0:38e03f9fa18a 
Library to control the 12 Bits Analog Digital Converter; MCP4921

Who changed what in which revision?

UserRevisionLine numberNew contents of line
adelino 0:38e03f9fa18a 1 #ifndef MCP4921_H
adelino 0:38e03f9fa18a 2 #define MCP4921_H
adelino 0:38e03f9fa18a 3
adelino 0:38e03f9fa18a 4 #include "mbed.h"
adelino 0:38e03f9fa18a 5
adelino 0:38e03f9fa18a 6 /**
adelino 0:38e03f9fa18a 7 * The MCP4921 is a single 12 bit DAC.
adelino 0:38e03f9fa18a 8 The maximum voltage output is limited by the input voltage at V_DD which can go up to about 5.5V.
adelino 0:38e03f9fa18a 9
adelino 0:38e03f9fa18a 10 * Datasheet: http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en020398
adelino 0:38e03f9fa18a 11 *
adelino 1:1352606a60c6 12 *Exemple:
adelino 1:1352606a60c6 13 @code
adelino 1:1352606a60c6 14 //Mbed Mcp4921
adelino 1:1352606a60c6 15 //p11: Mosi <---> p4:Sdi
adelino 1:1352606a60c6 16 //p12: Miso No Connected
adelino 1:1352606a60c6 17 //p13: Sck <---> p3:Sck
adelino 1:1352606a60c6 18 //p14 <---> p2:Cs
adelino 1:1352606a60c6 19 //Vout <---> p1:Vdd
adelino 1:1352606a60c6 20 //Vout <---> p6: Vref
adelino 1:1352606a60c6 21 //Gnd <---> p7:Gnd
adelino 1:1352606a60c6 22 //Gnd <---> p5:Ldac
adelino 1:1352606a60c6 23
adelino 1:1352606a60c6 24 #include "mbed.h"
adelino 1:1352606a60c6 25 #include "Mcp4921.h"
adelino 1:1352606a60c6 26
adelino 1:1352606a60c6 27 Mcp4921 cna(p11,p13,p14,500000);
adelino 1:1352606a60c6 28 int main()
adelino 1:1352606a60c6 29 {
adelino 1:1352606a60c6 30 static int mv;
adelino 1:1352606a60c6 31 while(1) {
adelino 1:1352606a60c6 32 cna.write_mV(mv);
adelino 1:1352606a60c6 33
adelino 1:1352606a60c6 34 mv+=500;
adelino 1:1352606a60c6 35 if(mv>4000)
adelino 1:1352606a60c6 36 mv=0;
adelino 1:1352606a60c6 37 }
adelino 1:1352606a60c6 38 }
adelino 1:1352606a60c6 39
adelino 1:1352606a60c6 40 @endcode
adelino 0:38e03f9fa18a 41 */
adelino 0:38e03f9fa18a 42
adelino 0:38e03f9fa18a 43 class Mcp4921
adelino 0:38e03f9fa18a 44 {
adelino 0:38e03f9fa18a 45
adelino 0:38e03f9fa18a 46 public:
adelino 1:1352606a60c6 47 /**Initializes the MCP 4921 DAC with the frequency
adelino 1:1352606a60c6 48
adelino 0:38e03f9fa18a 49 */
adelino 0:38e03f9fa18a 50 Mcp4921(PinName _mosi,PinName _sck,PinName _cs, int _frequency);
adelino 0:38e03f9fa18a 51
adelino 1:1352606a60c6 52 /** @returns The frequency use by the Mcp4921
adelino 0:38e03f9fa18a 53 */
adelino 0:38e03f9fa18a 54 int getFrequency(void);
adelino 0:38e03f9fa18a 55
adelino 0:38e03f9fa18a 56 /** Writes a value between 0-4095 to the currently selected DAC output
adelino 1:1352606a60c6 57 * @param dataIntNum A value from 0-4095 to write to the DAC register
adelino 0:38e03f9fa18a 58 */
adelino 0:38e03f9fa18a 59 void write(int dataIntNum);
adelino 0:38e03f9fa18a 60
adelino 0:38e03f9fa18a 61 /** Writes a float value between 0.0-1.0 to the currently selected DAC output
adelino 1:1352606a60c6 62 * @param dataFloat A value from 0.0-1.0 to write to the DAC register
adelino 0:38e03f9fa18a 63 */
adelino 0:38e03f9fa18a 64 void write(float dataFloat);
adelino 0:38e03f9fa18a 65
adelino 0:38e03f9fa18a 66 /** Writes a value in mV to the DAC outputs.
adelino 0:38e03f9fa18a 67 * The output will only be accurate if Vref is set to the appropriate voltage reference scaling factor.
adelino 0:38e03f9fa18a 68 * @param millivolt The desired voltage output in millivolts
adelino 0:38e03f9fa18a 69 */
adelino 0:38e03f9fa18a 70 void write_mV(int millivolt);
adelino 0:38e03f9fa18a 71
adelino 0:38e03f9fa18a 72 /**An operator for shorthand write(int)
adelino 0:38e03f9fa18a 73 */
adelino 0:38e03f9fa18a 74 void operator=(int dataIntNum);
adelino 0:38e03f9fa18a 75
adelino 0:38e03f9fa18a 76
adelino 0:38e03f9fa18a 77 /**An operator for shorthand write(float)
adelino 0:38e03f9fa18a 78 */
adelino 0:38e03f9fa18a 79 void operator=(float dataFloat);
adelino 0:38e03f9fa18a 80
adelino 0:38e03f9fa18a 81
adelino 0:38e03f9fa18a 82 protected:
adelino 0:38e03f9fa18a 83 //
adelino 0:38e03f9fa18a 84 void setup(void);
adelino 0:38e03f9fa18a 85 SPI mySPI;
adelino 0:38e03f9fa18a 86 DigitalOut myCs;
adelino 0:38e03f9fa18a 87 int myFrequency;
adelino 0:38e03f9fa18a 88
adelino 0:38e03f9fa18a 89 };
adelino 0:38e03f9fa18a 90
adelino 0:38e03f9fa18a 91 #endif