P7100.cpp

00001 #include "mbed.h"
00002 #include "P7100.h"
00003 
00004 P7100::P7100(PinName mosi, PinName miso, PinName sclk, PinName pin) : spi(mosi, miso, sclk), cs(pin)
00005 {   
00006     cs = 0;
00007     spi.format(7, 0);       //通信形式定義
00008     spi.frequency(1000000); //クロックレート
00009 }
00010 
00011 P7100::~P7100()
00012 {
00013 }
00014 
00015 float P7100::v_read()
00016 {
00017     uint8_t high, low;      //1バイトの符号なし整数
00018     float value, v;    //値，電圧
00019     
00020     cs = 0;             //通信開始
00021         
00022     spi.write(0x60);    //シングル
00023     //spi.write(0x40);  //差動
00024     
00025     high = spi.write(0x00);
00026     low = spi.write(0x00);
00027     
00028     low = (high << 5) | (low >> 2);
00029     high = high >> 3;
00030     
00031     value = (high << 8) | low;
00032     
00033     v = value / 4096 * 5.0;     //出力電圧
00034 
00035     cs = 1;             //通信終了
00036     
00037     return v;
00038 }