ADC128S.h

00001 /* mbed library for the National Semiconductor ADC128S family of analog to digital converters
00002  *
00003  * by Michael Shimniok - http://www.bot-thoughts.com/
00004  */
00005  
00006  /** An interface for driving a National Semiconductor ADC128Sxxx analog to digital converter using SPI
00007  *
00008  * @code
00009  * #include "mbed.h"
00010  * #include "ADC128S.h"
00011  *
00012  * Serial pc(USBTX, USBRX); // tx, rx
00013  * ADC128S adc(p5, p6, p7, p15); // mosi, miso, sck, cs
00014  *
00015  * int main() {
00016  *   unsigned int result;
00017  *   pc.baud(115200);    
00018  *
00019  *   while(1) {
00020  *     for (int i = 0; i < 8; i++) {
00021  *       result = adc.read(i);
00022  *       pc.printf("ADC(%d)=%d\n", i, result);
00023  *     }
00024  *     pc.printf("\n");
00025  *   }
00026  * }
00027  * @endcode
00028  */
00029 class ADC128S {
00030 public:
00031     /** Create an ADC128S interface
00032      *
00033      * @param mosi  MOSI line
00034      * @param miso  MISO line
00035      * @param sck   SCK line
00036      * @param cs    !CS/!SS line
00037      */
00038     ADC128S(PinName mosi, PinName miso, PinName sck, PinName cs);
00039 
00040 
00041     /** Get the next channel to be converted with next call to read()
00042      *
00043      * @returns an integer representing the adc channel about to be converted
00044      */ 
00045     int getChannel(void);
00046 
00047     /** Set channel to be used for the next conversion.
00048      *
00049      * @param channel is the adc channel you want to read with next call to read()
00050      */
00051     void setChannel(int channel);
00052 
00053     /** Convert the current channel and return the result and prepare to read the next channel.
00054      *  The channel will count to 7 and then wrap around to 0.  See also: setChannel()
00055      *
00056      * @param returns conversion for the curent channel and prepares to read the next channel
00057      */
00058     unsigned int read(void);
00059 
00060     /** Read in analog value from the specified ADC channel
00061      *
00062      * @param channel  The ADC channel to read
00063      * @returns the analog to digital conversion result
00064      */
00065     unsigned int read(int channel);
00066 
00067 private:
00068     SPI _adc;
00069     DigitalOut _cs;
00070     int _channel;
00071 };