Mario Poneder / ADC_AD7190

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AD7190.cpp@0:49fe1d7a6628, 2014-01-28 (annotated)

Committer:
MarioPoneder
Date:
Tue Jan 28 09:42:48 2014 +0000
Revision:
0:49fe1d7a6628
Child:
1:00d6e45e037a
a

Who changed what in which revision?

UserRevisionLine numberNew contents of line
MarioPoneder 0:49fe1d7a6628 1 /***************************************************************************//**
MarioPoneder 0:49fe1d7a6628 2 * @file AD7190.cpp
MarioPoneder 0:49fe1d7a6628 3 * @brief Implementation of the AD7190 driver.
MarioPoneder 0:49fe1d7a6628 4 * @author Mario Poneder
MarioPoneder 0:49fe1d7a6628 5 * @date 28/01/2013
MarioPoneder 0:49fe1d7a6628 6 *
MarioPoneder 0:49fe1d7a6628 7 * This class is based on the implementation from Dan Nechita (Analog Devices).
MarioPoneder 0:49fe1d7a6628 8 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 9
MarioPoneder 0:49fe1d7a6628 10 /******************************************************************************/
MarioPoneder 0:49fe1d7a6628 11 /***************************** Include Files **********************************/
MarioPoneder 0:49fe1d7a6628 12 /******************************************************************************/
MarioPoneder 0:49fe1d7a6628 13 #include "AD7190.h"
MarioPoneder 0:49fe1d7a6628 14
MarioPoneder 0:49fe1d7a6628 15 /***************************************************************************//**
MarioPoneder 0:49fe1d7a6628 16 * @brief Constructs the AD7190 class. This library is designed for single
MarioPoneder 0:49fe1d7a6628 17 * slave operation. Therefore no chip-select pin is required.
MarioPoneder 0:49fe1d7a6628 18 *
MarioPoneder 0:49fe1d7a6628 19 * @param rdy RDY (DOUT/RDY)
MarioPoneder 0:49fe1d7a6628 20 * @param mosi DIN
MarioPoneder 0:49fe1d7a6628 21 * @param miso DOUT (DOUT/RDY), must be a different pin than rdy.
MarioPoneder 0:49fe1d7a6628 22 * @param sclk SCLK
MarioPoneder 0:49fe1d7a6628 23 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 24 AD7190::AD7190(PinName rdy, PinName mosi, PinName miso, PinName sclk)
MarioPoneder 0:49fe1d7a6628 25 : _rdy(rdy), _rdyInt(rdy), _spi(mosi, miso, sclk)
MarioPoneder 0:49fe1d7a6628 26 {
MarioPoneder 0:49fe1d7a6628 27 ;
MarioPoneder 0:49fe1d7a6628 28 }
MarioPoneder 0:49fe1d7a6628 29
MarioPoneder 0:49fe1d7a6628 30 /***************************************************************************//**
MarioPoneder 0:49fe1d7a6628 31 * @brief This interrupt routine gets called after every finished conversion
MarioPoneder 0:49fe1d7a6628 32 * in continous read mode. It reads 4 bytes of data, the sample takes
MarioPoneder 0:49fe1d7a6628 33 * 3 bytes and the status register 1 byte.
MarioPoneder 0:49fe1d7a6628 34 * Moreover the sample callback function, which has to to take the
MarioPoneder 0:49fe1d7a6628 35 * parameters 'data' and 'channel', gets called.
MarioPoneder 0:49fe1d7a6628 36 *
MarioPoneder 0:49fe1d7a6628 37 * @return None, because this is an interrupt routine.
MarioPoneder 0:49fe1d7a6628 38 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 39 void AD7190::SampleInterrupt(void)
MarioPoneder 0:49fe1d7a6628 40 {
MarioPoneder 0:49fe1d7a6628 41 static unsigned long buffer;
MarioPoneder 0:49fe1d7a6628 42 static unsigned char i;
MarioPoneder 0:49fe1d7a6628 43 this->_rdyInt.fall(NULL);
MarioPoneder 0:49fe1d7a6628 44 for(i = 1; i <= 4; i++) {
MarioPoneder 0:49fe1d7a6628 45 buffer = (buffer << 8) + _spi.write(0x00);
MarioPoneder 0:49fe1d7a6628 46 }
MarioPoneder 0:49fe1d7a6628 47 this->sampleCallbackFunction(buffer >> 8, buffer & 0x07);
MarioPoneder 0:49fe1d7a6628 48 this->_rdyInt.fall(this, &AD7190::SampleInterrupt);
MarioPoneder 0:49fe1d7a6628 49 }
MarioPoneder 0:49fe1d7a6628 50
MarioPoneder 0:49fe1d7a6628 51 /***************************************************************************//**
MarioPoneder 0:49fe1d7a6628 52 * @brief Starts the interrupt-driven sampling process and sets the AD7190's
MarioPoneder 0:49fe1d7a6628 53 * continuous read mode flag.
MarioPoneder 0:49fe1d7a6628 54 *
MarioPoneder 0:49fe1d7a6628 55 * @param sampleCallbackFunction Pointer to the sample callback function,
MarioPoneder 0:49fe1d7a6628 56 * which has to to take the parameters 'data'
MarioPoneder 0:49fe1d7a6628 57 * and 'channel'.
MarioPoneder 0:49fe1d7a6628 58 *
MarioPoneder 0:49fe1d7a6628 59 * @return None.
MarioPoneder 0:49fe1d7a6628 60 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 61 void AD7190::StartContinuousRead(pSampleCallback_t sampleCallbackFunction)
MarioPoneder 0:49fe1d7a6628 62 {
MarioPoneder 0:49fe1d7a6628 63 this->sampleCallbackFunction = sampleCallbackFunction;
MarioPoneder 0:49fe1d7a6628 64 this->WaitRdyGoLow();
MarioPoneder 0:49fe1d7a6628 65 this->_spi.write(COMM_READ | COMM_CREAD | COMM_ADDR(REG_DATA));
MarioPoneder 0:49fe1d7a6628 66 this->_rdyInt.fall(this, &AD7190::SampleInterrupt);
MarioPoneder 0:49fe1d7a6628 67 }
MarioPoneder 0:49fe1d7a6628 68
MarioPoneder 0:49fe1d7a6628 69 /***************************************************************************//**
MarioPoneder 0:49fe1d7a6628 70 * @brief Stops the interrupt-driven sampling process and disables the AD7190's
MarioPoneder 0:49fe1d7a6628 71 * continuous read mode.
MarioPoneder 0:49fe1d7a6628 72 *
MarioPoneder 0:49fe1d7a6628 73 * @return None.
MarioPoneder 0:49fe1d7a6628 74 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 75 void AD7190::StopContinuousRead(void)
MarioPoneder 0:49fe1d7a6628 76 {
MarioPoneder 0:49fe1d7a6628 77 this->_rdyInt.fall(NULL);
MarioPoneder 0:49fe1d7a6628 78 this->WaitRdyGoLow();
MarioPoneder 0:49fe1d7a6628 79 this->_spi.write(COMM_READ | COMM_ADDR(REG_DATA));
MarioPoneder 0:49fe1d7a6628 80 }
MarioPoneder 0:49fe1d7a6628 81
MarioPoneder 0:49fe1d7a6628 82 /***************************************************************************//**
MarioPoneder 0:49fe1d7a6628 83 * @brief Writes the specified contents to the specified on-chip register.
MarioPoneder 0:49fe1d7a6628 84 *
MarioPoneder 0:49fe1d7a6628 85 * @param registerAddress Address of the register.
MarioPoneder 0:49fe1d7a6628 86 * @param registerValue Contents to write.
MarioPoneder 0:49fe1d7a6628 87 *
MarioPoneder 0:49fe1d7a6628 88 * @return None.
MarioPoneder 0:49fe1d7a6628 89 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 90 void AD7190::SetRegisterValue(unsigned char registerAddress, unsigned long registerValue)
MarioPoneder 0:49fe1d7a6628 91 {
MarioPoneder 0:49fe1d7a6628 92 static unsigned char *dataPointer, bytesNr;
MarioPoneder 0:49fe1d7a6628 93 dataPointer = (unsigned char*)&registerValue;
MarioPoneder 0:49fe1d7a6628 94
MarioPoneder 0:49fe1d7a6628 95 switch(registerAddress) {
MarioPoneder 0:49fe1d7a6628 96 case REG_ID:
MarioPoneder 0:49fe1d7a6628 97 case REG_GPOCON:
MarioPoneder 0:49fe1d7a6628 98 bytesNr = 1;
MarioPoneder 0:49fe1d7a6628 99 break;
MarioPoneder 0:49fe1d7a6628 100 case REG_MODE:
MarioPoneder 0:49fe1d7a6628 101 dataPointer += 2;
MarioPoneder 0:49fe1d7a6628 102 case REG_CONF:
MarioPoneder 0:49fe1d7a6628 103 registerValue |= (1 << 19);
MarioPoneder 0:49fe1d7a6628 104 case REG_OFFSET:
MarioPoneder 0:49fe1d7a6628 105 case REG_FULLSCALE:
MarioPoneder 0:49fe1d7a6628 106 bytesNr = 3;
MarioPoneder 0:49fe1d7a6628 107 break;
MarioPoneder 0:49fe1d7a6628 108 default:
MarioPoneder 0:49fe1d7a6628 109 bytesNr = 0;
MarioPoneder 0:49fe1d7a6628 110 }
MarioPoneder 0:49fe1d7a6628 111
MarioPoneder 0:49fe1d7a6628 112 this->_spi.write(COMM_WRITE | COMM_ADDR(registerAddress));
MarioPoneder 0:49fe1d7a6628 113 for(; bytesNr > 0; bytesNr--) {
MarioPoneder 0:49fe1d7a6628 114 this->_spi.write(*dataPointer);
MarioPoneder 0:49fe1d7a6628 115 registerAddress == REG_MODE ? dataPointer -- : dataPointer ++;
MarioPoneder 0:49fe1d7a6628 116 }
MarioPoneder 0:49fe1d7a6628 117 }
MarioPoneder 0:49fe1d7a6628 118
MarioPoneder 0:49fe1d7a6628 119 /***************************************************************************//**
MarioPoneder 0:49fe1d7a6628 120 * @brief Reads the contents of the specified on-chip register.
MarioPoneder 0:49fe1d7a6628 121 *
MarioPoneder 0:49fe1d7a6628 122 * @param registerAddress Address of the register.
MarioPoneder 0:49fe1d7a6628 123 *
MarioPoneder 0:49fe1d7a6628 124 * @return Contents of the register.
MarioPoneder 0:49fe1d7a6628 125 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 126 unsigned long AD7190::GetRegisterValue(unsigned char registerAddress)
MarioPoneder 0:49fe1d7a6628 127 {
MarioPoneder 0:49fe1d7a6628 128 static unsigned long buffer = 0;
MarioPoneder 0:49fe1d7a6628 129 static unsigned char bytesNr, i;
MarioPoneder 0:49fe1d7a6628 130
MarioPoneder 0:49fe1d7a6628 131 switch (registerAddress) {
MarioPoneder 0:49fe1d7a6628 132 case REG_STAT:
MarioPoneder 0:49fe1d7a6628 133 case REG_ID:
MarioPoneder 0:49fe1d7a6628 134 case REG_GPOCON:
MarioPoneder 0:49fe1d7a6628 135 bytesNr = 1;
MarioPoneder 0:49fe1d7a6628 136 break;
MarioPoneder 0:49fe1d7a6628 137 case REG_MODE:
MarioPoneder 0:49fe1d7a6628 138 case REG_CONF:
MarioPoneder 0:49fe1d7a6628 139 case REG_DATA:
MarioPoneder 0:49fe1d7a6628 140 case REG_OFFSET:
MarioPoneder 0:49fe1d7a6628 141 case REG_FULLSCALE:
MarioPoneder 0:49fe1d7a6628 142 bytesNr = 3;
MarioPoneder 0:49fe1d7a6628 143 break;
MarioPoneder 0:49fe1d7a6628 144 default:
MarioPoneder 0:49fe1d7a6628 145 bytesNr = 0;
MarioPoneder 0:49fe1d7a6628 146 }
MarioPoneder 0:49fe1d7a6628 147
MarioPoneder 0:49fe1d7a6628 148 this->_spi.write(COMM_READ | COMM_ADDR(registerAddress));
MarioPoneder 0:49fe1d7a6628 149 for(i = 1; i <= bytesNr; i++) {
MarioPoneder 0:49fe1d7a6628 150 buffer = (buffer << 8) + _spi.write(0x00);
MarioPoneder 0:49fe1d7a6628 151 }
MarioPoneder 0:49fe1d7a6628 152 return buffer;
MarioPoneder 0:49fe1d7a6628 153 }
MarioPoneder 0:49fe1d7a6628 154
MarioPoneder 0:49fe1d7a6628 155 /***************************************************************************//**
MarioPoneder 0:49fe1d7a6628 156 * @brief Initialises the SPI bus, resets the AD7190 and checks if it is
MarioPoneder 0:49fe1d7a6628 157 * responding.
MarioPoneder 0:49fe1d7a6628 158 *
MarioPoneder 0:49fe1d7a6628 159 * @return True, if the ADC is respondig
MarioPoneder 0:49fe1d7a6628 160 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 161 bool AD7190::Init(void)
MarioPoneder 0:49fe1d7a6628 162 {
MarioPoneder 0:49fe1d7a6628 163 unsigned char regVal;
MarioPoneder 0:49fe1d7a6628 164
MarioPoneder 0:49fe1d7a6628 165 this->_spi.format(8, 3);
MarioPoneder 0:49fe1d7a6628 166 this->_spi.frequency(10000000);
MarioPoneder 0:49fe1d7a6628 167 this->Reset();
MarioPoneder 0:49fe1d7a6628 168 wait_ms(1);
MarioPoneder 0:49fe1d7a6628 169 regVal = this->GetRegisterValue(REG_ID);
MarioPoneder 0:49fe1d7a6628 170
MarioPoneder 0:49fe1d7a6628 171 return (regVal & ID_MASK) == ID_AD7190 ;
MarioPoneder 0:49fe1d7a6628 172 }
MarioPoneder 0:49fe1d7a6628 173
MarioPoneder 0:49fe1d7a6628 174 /***************************************************************************//**
MarioPoneder 0:49fe1d7a6628 175 * @brief Resets the AD7190.
MarioPoneder 0:49fe1d7a6628 176 *
MarioPoneder 0:49fe1d7a6628 177 * @return None.
MarioPoneder 0:49fe1d7a6628 178 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 179 void AD7190::Reset(void)
MarioPoneder 0:49fe1d7a6628 180 {
MarioPoneder 0:49fe1d7a6628 181 static unsigned char i;
MarioPoneder 0:49fe1d7a6628 182 this->_spi.write(0x01);
MarioPoneder 0:49fe1d7a6628 183 for(i = 0; i < 6; i++) {
MarioPoneder 0:49fe1d7a6628 184 this->_spi.write(0xFF);
MarioPoneder 0:49fe1d7a6628 185 }
MarioPoneder 0:49fe1d7a6628 186 }
MarioPoneder 0:49fe1d7a6628 187
MarioPoneder 0:49fe1d7a6628 188 /***************************************************************************//**
MarioPoneder 0:49fe1d7a6628 189 * @brief Waits for the RDY (DOUT/RDY) pin to go low.
MarioPoneder 0:49fe1d7a6628 190 *
MarioPoneder 0:49fe1d7a6628 191 * @return None.
MarioPoneder 0:49fe1d7a6628 192 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 193 void AD7190::WaitRdyGoLow(void)
MarioPoneder 0:49fe1d7a6628 194 {
MarioPoneder 0:49fe1d7a6628 195 for(; this->_rdy;);
MarioPoneder 0:49fe1d7a6628 196 }