Mario Poneder / ADC_AD7190

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AD7190.cpp@2:dc4217ca1fff, 2014-01-28 (annotated)

Committer:
MarioPoneder
Date:
Tue Jan 28 13:18:17 2014 +0000
Revision:
2:dc4217ca1fff
Parent:
1:00d6e45e037a 
doc done

Who changed what in which revision?

UserRevisionLine numberNew contents of line
MarioPoneder 0:49fe1d7a6628 1 #include "AD7190.h"
MarioPoneder 0:49fe1d7a6628 2
MarioPoneder 0:49fe1d7a6628 3 /***************************************************************************//**
MarioPoneder 2:dc4217ca1fff 4 * @brief Creates an instance of the AD7190 class. This class is designed
MarioPoneder 1:00d6e45e037a 5 * for single slave operation. Therefore no chip-select pin is required.
MarioPoneder 0:49fe1d7a6628 6 *
MarioPoneder 0:49fe1d7a6628 7 * @param rdy RDY (DOUT/RDY)
MarioPoneder 0:49fe1d7a6628 8 * @param mosi DIN
MarioPoneder 0:49fe1d7a6628 9 * @param miso DOUT (DOUT/RDY), must be a different pin than rdy.
MarioPoneder 0:49fe1d7a6628 10 * @param sclk SCLK
MarioPoneder 0:49fe1d7a6628 11 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 12 AD7190::AD7190(PinName rdy, PinName mosi, PinName miso, PinName sclk)
MarioPoneder 0:49fe1d7a6628 13 : _rdy(rdy), _rdyInt(rdy), _spi(mosi, miso, sclk)
MarioPoneder 0:49fe1d7a6628 14 {
MarioPoneder 0:49fe1d7a6628 15 ;
MarioPoneder 0:49fe1d7a6628 16 }
MarioPoneder 0:49fe1d7a6628 17
MarioPoneder 0:49fe1d7a6628 18 /***************************************************************************//**
MarioPoneder 0:49fe1d7a6628 19 * @brief This interrupt routine gets called after every finished conversion
MarioPoneder 0:49fe1d7a6628 20 * in continous read mode. It reads 4 bytes of data, the sample takes
MarioPoneder 0:49fe1d7a6628 21 * 3 bytes and the status register 1 byte.
MarioPoneder 2:dc4217ca1fff 22 * Moreover the sample callback function gets called.
MarioPoneder 0:49fe1d7a6628 23 *
MarioPoneder 0:49fe1d7a6628 24 * @return None, because this is an interrupt routine.
MarioPoneder 0:49fe1d7a6628 25 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 26 void AD7190::SampleInterrupt(void)
MarioPoneder 0:49fe1d7a6628 27 {
MarioPoneder 0:49fe1d7a6628 28 static unsigned long buffer;
MarioPoneder 0:49fe1d7a6628 29 static unsigned char i;
MarioPoneder 0:49fe1d7a6628 30 this->_rdyInt.fall(NULL);
MarioPoneder 0:49fe1d7a6628 31 for(i = 1; i <= 4; i++) {
MarioPoneder 0:49fe1d7a6628 32 buffer = (buffer << 8) + _spi.write(0x00);
MarioPoneder 0:49fe1d7a6628 33 }
MarioPoneder 0:49fe1d7a6628 34 this->sampleCallbackFunction(buffer >> 8, buffer & 0x07);
MarioPoneder 0:49fe1d7a6628 35 this->_rdyInt.fall(this, &AD7190::SampleInterrupt);
MarioPoneder 0:49fe1d7a6628 36 }
MarioPoneder 0:49fe1d7a6628 37
MarioPoneder 0:49fe1d7a6628 38 /***************************************************************************//**
MarioPoneder 0:49fe1d7a6628 39 * @brief Starts the interrupt-driven sampling process and sets the AD7190's
MarioPoneder 0:49fe1d7a6628 40 * continuous read mode flag.
MarioPoneder 0:49fe1d7a6628 41 *
MarioPoneder 2:dc4217ca1fff 42 * @param sampleCallbackFunction Pointer to the sample callback function.
MarioPoneder 2:dc4217ca1fff 43 * Example prototype:
MarioPoneder 2:dc4217ca1fff 44 * @code void SampleCallback(unsigned long data, unsigned char channel); @endcode
MarioPoneder 0:49fe1d7a6628 45 *
MarioPoneder 0:49fe1d7a6628 46 * @return None.
MarioPoneder 0:49fe1d7a6628 47 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 48 void AD7190::StartContinuousRead(pSampleCallback_t sampleCallbackFunction)
MarioPoneder 0:49fe1d7a6628 49 {
MarioPoneder 0:49fe1d7a6628 50 this->sampleCallbackFunction = sampleCallbackFunction;
MarioPoneder 0:49fe1d7a6628 51 this->WaitRdyGoLow();
MarioPoneder 0:49fe1d7a6628 52 this->_spi.write(COMM_READ | COMM_CREAD | COMM_ADDR(REG_DATA));
MarioPoneder 0:49fe1d7a6628 53 this->_rdyInt.fall(this, &AD7190::SampleInterrupt);
MarioPoneder 0:49fe1d7a6628 54 }
MarioPoneder 0:49fe1d7a6628 55
MarioPoneder 0:49fe1d7a6628 56 /***************************************************************************//**
MarioPoneder 0:49fe1d7a6628 57 * @brief Stops the interrupt-driven sampling process and disables the AD7190's
MarioPoneder 0:49fe1d7a6628 58 * continuous read mode.
MarioPoneder 0:49fe1d7a6628 59 *
MarioPoneder 0:49fe1d7a6628 60 * @return None.
MarioPoneder 0:49fe1d7a6628 61 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 62 void AD7190::StopContinuousRead(void)
MarioPoneder 0:49fe1d7a6628 63 {
MarioPoneder 0:49fe1d7a6628 64 this->_rdyInt.fall(NULL);
MarioPoneder 0:49fe1d7a6628 65 this->WaitRdyGoLow();
MarioPoneder 0:49fe1d7a6628 66 this->_spi.write(COMM_READ | COMM_ADDR(REG_DATA));
MarioPoneder 0:49fe1d7a6628 67 }
MarioPoneder 0:49fe1d7a6628 68
MarioPoneder 0:49fe1d7a6628 69 /***************************************************************************//**
MarioPoneder 0:49fe1d7a6628 70 * @brief Writes the specified contents to the specified on-chip register.
MarioPoneder 0:49fe1d7a6628 71 *
MarioPoneder 0:49fe1d7a6628 72 * @param registerAddress Address of the register.
MarioPoneder 0:49fe1d7a6628 73 * @param registerValue Contents to write.
MarioPoneder 0:49fe1d7a6628 74 *
MarioPoneder 0:49fe1d7a6628 75 * @return None.
MarioPoneder 0:49fe1d7a6628 76 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 77 void AD7190::SetRegisterValue(unsigned char registerAddress, unsigned long registerValue)
MarioPoneder 0:49fe1d7a6628 78 {
MarioPoneder 0:49fe1d7a6628 79 static unsigned char *dataPointer, bytesNr;
MarioPoneder 0:49fe1d7a6628 80 dataPointer = (unsigned char*)&registerValue;
MarioPoneder 0:49fe1d7a6628 81
MarioPoneder 0:49fe1d7a6628 82 switch(registerAddress) {
MarioPoneder 0:49fe1d7a6628 83 case REG_ID:
MarioPoneder 0:49fe1d7a6628 84 case REG_GPOCON:
MarioPoneder 0:49fe1d7a6628 85 bytesNr = 1;
MarioPoneder 0:49fe1d7a6628 86 break;
MarioPoneder 0:49fe1d7a6628 87 case REG_MODE:
MarioPoneder 0:49fe1d7a6628 88 dataPointer += 2;
MarioPoneder 0:49fe1d7a6628 89 case REG_CONF:
MarioPoneder 0:49fe1d7a6628 90 registerValue |= (1 << 19);
MarioPoneder 0:49fe1d7a6628 91 case REG_OFFSET:
MarioPoneder 0:49fe1d7a6628 92 case REG_FULLSCALE:
MarioPoneder 0:49fe1d7a6628 93 bytesNr = 3;
MarioPoneder 0:49fe1d7a6628 94 break;
MarioPoneder 0:49fe1d7a6628 95 default:
MarioPoneder 0:49fe1d7a6628 96 bytesNr = 0;
MarioPoneder 0:49fe1d7a6628 97 }
MarioPoneder 0:49fe1d7a6628 98
MarioPoneder 0:49fe1d7a6628 99 this->_spi.write(COMM_WRITE | COMM_ADDR(registerAddress));
MarioPoneder 0:49fe1d7a6628 100 for(; bytesNr > 0; bytesNr--) {
MarioPoneder 0:49fe1d7a6628 101 this->_spi.write(*dataPointer);
MarioPoneder 0:49fe1d7a6628 102 registerAddress == REG_MODE ? dataPointer -- : dataPointer ++;
MarioPoneder 0:49fe1d7a6628 103 }
MarioPoneder 0:49fe1d7a6628 104 }
MarioPoneder 0:49fe1d7a6628 105
MarioPoneder 0:49fe1d7a6628 106 /***************************************************************************//**
MarioPoneder 0:49fe1d7a6628 107 * @brief Reads the contents of the specified on-chip register.
MarioPoneder 0:49fe1d7a6628 108 *
MarioPoneder 0:49fe1d7a6628 109 * @param registerAddress Address of the register.
MarioPoneder 0:49fe1d7a6628 110 *
MarioPoneder 0:49fe1d7a6628 111 * @return Contents of the register.
MarioPoneder 0:49fe1d7a6628 112 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 113 unsigned long AD7190::GetRegisterValue(unsigned char registerAddress)
MarioPoneder 0:49fe1d7a6628 114 {
MarioPoneder 0:49fe1d7a6628 115 static unsigned long buffer = 0;
MarioPoneder 0:49fe1d7a6628 116 static unsigned char bytesNr, i;
MarioPoneder 0:49fe1d7a6628 117
MarioPoneder 0:49fe1d7a6628 118 switch (registerAddress) {
MarioPoneder 0:49fe1d7a6628 119 case REG_STAT:
MarioPoneder 0:49fe1d7a6628 120 case REG_ID:
MarioPoneder 0:49fe1d7a6628 121 case REG_GPOCON:
MarioPoneder 0:49fe1d7a6628 122 bytesNr = 1;
MarioPoneder 0:49fe1d7a6628 123 break;
MarioPoneder 0:49fe1d7a6628 124 case REG_MODE:
MarioPoneder 0:49fe1d7a6628 125 case REG_CONF:
MarioPoneder 0:49fe1d7a6628 126 case REG_DATA:
MarioPoneder 0:49fe1d7a6628 127 case REG_OFFSET:
MarioPoneder 0:49fe1d7a6628 128 case REG_FULLSCALE:
MarioPoneder 0:49fe1d7a6628 129 bytesNr = 3;
MarioPoneder 0:49fe1d7a6628 130 break;
MarioPoneder 0:49fe1d7a6628 131 default:
MarioPoneder 0:49fe1d7a6628 132 bytesNr = 0;
MarioPoneder 0:49fe1d7a6628 133 }
MarioPoneder 0:49fe1d7a6628 134
MarioPoneder 0:49fe1d7a6628 135 this->_spi.write(COMM_READ | COMM_ADDR(registerAddress));
MarioPoneder 0:49fe1d7a6628 136 for(i = 1; i <= bytesNr; i++) {
MarioPoneder 0:49fe1d7a6628 137 buffer = (buffer << 8) + _spi.write(0x00);
MarioPoneder 0:49fe1d7a6628 138 }
MarioPoneder 0:49fe1d7a6628 139 return buffer;
MarioPoneder 0:49fe1d7a6628 140 }
MarioPoneder 0:49fe1d7a6628 141
MarioPoneder 0:49fe1d7a6628 142 /***************************************************************************//**
MarioPoneder 0:49fe1d7a6628 143 * @brief Initialises the SPI bus, resets the AD7190 and checks if it is
MarioPoneder 0:49fe1d7a6628 144 * responding.
MarioPoneder 0:49fe1d7a6628 145 *
MarioPoneder 0:49fe1d7a6628 146 * @return True, if the ADC is respondig
MarioPoneder 0:49fe1d7a6628 147 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 148 bool AD7190::Init(void)
MarioPoneder 0:49fe1d7a6628 149 {
MarioPoneder 0:49fe1d7a6628 150 unsigned char regVal;
MarioPoneder 0:49fe1d7a6628 151
MarioPoneder 0:49fe1d7a6628 152 this->_spi.format(8, 3);
MarioPoneder 0:49fe1d7a6628 153 this->_spi.frequency(10000000);
MarioPoneder 0:49fe1d7a6628 154 this->Reset();
MarioPoneder 0:49fe1d7a6628 155 wait_ms(1);
MarioPoneder 0:49fe1d7a6628 156 regVal = this->GetRegisterValue(REG_ID);
MarioPoneder 0:49fe1d7a6628 157
MarioPoneder 0:49fe1d7a6628 158 return (regVal & ID_MASK) == ID_AD7190 ;
MarioPoneder 0:49fe1d7a6628 159 }
MarioPoneder 0:49fe1d7a6628 160
MarioPoneder 0:49fe1d7a6628 161 /***************************************************************************//**
MarioPoneder 0:49fe1d7a6628 162 * @brief Resets the AD7190.
MarioPoneder 0:49fe1d7a6628 163 *
MarioPoneder 0:49fe1d7a6628 164 * @return None.
MarioPoneder 0:49fe1d7a6628 165 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 166 void AD7190::Reset(void)
MarioPoneder 0:49fe1d7a6628 167 {
MarioPoneder 0:49fe1d7a6628 168 static unsigned char i;
MarioPoneder 0:49fe1d7a6628 169 this->_spi.write(0x01);
MarioPoneder 0:49fe1d7a6628 170 for(i = 0; i < 6; i++) {
MarioPoneder 0:49fe1d7a6628 171 this->_spi.write(0xFF);
MarioPoneder 0:49fe1d7a6628 172 }
MarioPoneder 0:49fe1d7a6628 173 }
MarioPoneder 0:49fe1d7a6628 174
MarioPoneder 0:49fe1d7a6628 175 /***************************************************************************//**
MarioPoneder 0:49fe1d7a6628 176 * @brief Waits for the RDY (DOUT/RDY) pin to go low.
MarioPoneder 0:49fe1d7a6628 177 *
MarioPoneder 0:49fe1d7a6628 178 * @return None.
MarioPoneder 0:49fe1d7a6628 179 *******************************************************************************/
MarioPoneder 0:49fe1d7a6628 180 void AD7190::WaitRdyGoLow(void)
MarioPoneder 0:49fe1d7a6628 181 {
MarioPoneder 0:49fe1d7a6628 182 for(; this->_rdy;);
MarioPoneder 0:49fe1d7a6628 183 }