main.cpp

00001 #include "mbed.h"
00002 #include "ADS1256.h"
00003 
00004 #define SPI_MOSI  D11
00005 #define SPI_MISO  D12
00006 #define SPI_SCLK  D13
00007 #define CHIP_SLCT D9
00008 #define CHANNEL_NUM 4
00009 
00010 #define NO_OF_SENSORS  4 // 1- 1 sensor, 2- 2 sensors, 3- 3 sensors, 4- 4 sensors
00011 
00012 DigitalIn ndrdy =  D10;
00013 DigitalOut cs = CHIP_SLCT;
00014 
00015 Serial pc(USBTX, USBRX); 
00016 
00017 SPI spi(SPI_MOSI, SPI_MISO, SPI_SCLK);
00018 ADS1256 ads(&spi, &ndrdy, &cs);
00019 
00020 int32_t ads_sum = 0;
00021 
00022 /* 
00023     @brief: Settling time using the Input Multiplexer.
00024 */
00025 #if NO_OF_SENSORS == 1
00026     void readDataMux()
00027     {
00028         uint8_t channel = 0;
00029         ads.readDiffChannel(channel);    
00030 
00031         for (int i=0; i<CHANNEL_NUM; i++)
00032         {
00033             ads_sum+= ads.adcNow[i];
00034         }
00035     }
00036 #elif NO_OF_SENSORS == 2
00037     void readDataMux()
00038     {
00039         uint8_t channel = 0;
00040         while(channel < (CHANNEL_NUM-2))
00041         {
00042             ads.readDiffChannel(++channel);    
00043         } 
00044         channel = 0;
00045         for (int i=0; i<CHANNEL_NUM; i++)
00046         {
00047             ads_sum+= ads.adcNow[i];
00048         }
00049     }
00050 #elif NO_OF_SENSORS == 3
00051     void readDataMux()
00052 {
00053     uint8_t channel = 0;
00054     while(channel < CHANNEL_NUM-1)
00055     {
00056         ads.readDiffChannel(++channel);    
00057     } 
00058     channel = 0;
00059     for (int i=0; i<CHANNEL_NUM; i++)
00060     {
00061         ads_sum+= ads.adcNow[i];
00062     }
00063 }
00064 #elif NO_OF_SENSORS == 4
00065     void readDataMux()
00066         {
00067             uint8_t channel = 0;
00068             while(channel < CHANNEL_NUM)
00069             {
00070                 ads.readDiffChannel(++channel);    
00071             } 
00072             channel = 0;
00073             for (int i=0; i<CHANNEL_NUM; i++)
00074             {
00075                 ads_sum+= ads.adcNow[i];
00076             }
00077         }
00078 #else
00079        void readDataMux()
00080        {
00081             pc.printf("INVALID NUMBER OF SENSORS INITIALIZED\n");
00082        }
00083 #endif
00084 
00085 void process(void)
00086 {
00087 
00088     readDataMux();
00089     pc.printf("The total value read is %d\n", ads_sum);
00090     ads_sum=0;
00091     wait_us(1000);
00092 
00093     pc.printf("The value in adcNow[0] is %d\n", ads.adcNow[0]);
00094     pc.printf("The value in adcNow[1] is %d\n", ads.adcNow[1]);
00095     pc.printf("The value in adcNow[2] is %d\n", ads.adcNow[2]);
00096     pc.printf("The value in adcNow[3] is %d\n", ads.adcNow[3]);
00097 }
00098 
00099 int main()
00100 {
00101     /* @brief Set the configuration parameters:
00102         channel == 0(0x01h),
00103         PGA gain == 64,
00104         Buffer == 1 (enabled),
00105         Datarate == 2.5SPS.
00106         Auto_calibration has also been enabled
00107      */
00108     ads.cfgADC();
00109     pc.printf("Device configuration is successful\n");
00110     ads.setDiffChannel(); // Redundancy feature just to ensure that the channel is set correctly.
00111     pc.printf("The set gain value is %d\n", ads.getGainVal());
00112     
00113     /*TODO: Calibration*/
00114     ads.selfCal();
00115     ads.sysOffCal();
00116     
00117     while(1) 
00118     {
00119         process();
00120         wait_ms(500);
00121     }
00122 }