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ads12xx.cpp
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ads12xx.cpp
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#include "ads12xx.h"
// change waitforDRDY() to poll instead of interrupt
// ads12xx setup
ads12xx::ads12xx() {}
void ads12xx::begin(int CS, int START, int DRDY, int _RESET) {
pinMode(CS, OUTPUT); // set the slaveSelectPin as an output:
digitalWriteFast(CS, HIGH); // CS HIGH = nothing selected
pinMode(DRDY, INPUT); // DRDY read
pinMode(START, OUTPUT);
digitalWriteFast(START, HIGH);
pinMode(RESET, OUTPUT); // set the slaveSelectPin as an output:
digitalWriteFast(RESET, HIGH);
_CS = CS;
_DRDY = DRDY;
delay(500);
SPI.begin();
// attachInterrupt(_DRDY, DRDY_Interrupt, FALLING); //Interrupt setup for DRDY detection
delay(500);
}
bool ads12xx::waitforDRDY(int rdy) { // polled, not interrupt
int timeout=0;
timeout = millis();
while (digitalReadFast(rdy) == 1) {
if(millis() - timeout > 1000)
return false; // data should always be ready by now
}
return true;
}
#define PAUSE delayMicroseconds(25) // was 10 usec
// function to get a 3byte conversion result from the adc
// BUGGY: sometimes skips a byte (!?)
long ads12xx::GetConversion() {
int32_t regData;
if(ads12xx::waitforDRDY(_DRDY)==0){ // Wait until DRDY is LOW
Serial.println("Timeout in Wait_for_DRDY");
return 0;
};
SPI.beginTransaction(SPISettings(SPI_SPEED, MSBFIRST, SPI_MODE1));
PAUSE;
digitalWriteFast(_CS, LOW); //Pull SS Low to Enable Communications with ADS1247
PAUSE; PAUSE; // Datasheet claims 0 setup time needed here. Untrue?
SPI.transfer(RDATA); //Issue RDATA
PAUSE;
// assemble 3 bytes into one 32 bit word
regData = ((uint32_t)SPI.transfer(NOP) << 16) & 0x00FF0000;
regData |= ((uint32_t)SPI.transfer(NOP) << 8);
regData |= SPI.transfer(NOP);
PAUSE; PAUSE;
digitalWriteFast(_CS, HIGH);
// PAUSE;
SPI.endTransaction();
// sign-extend negative 24-bit number to i32
if (regData & 0x800000)
{ regData |= 0xFF000000; }
return regData;
}
// function to write a register value to the adc
// argumen: adress for the register to write into, value to write
void ads12xx::SetRegisterValue(uint8_t regAdress, uint8_t regValue) {
#ifdef ADS1248
if (regAdress == IDAC0) {
regValue = regValue | IDAC0_ID; // add non 0 non-write register value IDAC0_ID
}
#endif
uint8_t regValuePre = ads12xx::GetRegisterValue(regAdress);
if (regValue != regValuePre) {
//digitalWriteFast(_START, HIGH);
delayMicroseconds(10);
//waitforDRDY(_DRDY);
SPI.beginTransaction(SPISettings(SPI_SPEED, MSBFIRST, SPI_MODE1)); // initialize SPI with SPI_SPEED, MSB first, SPI Mode1
digitalWriteFast(_CS, LOW);
delayMicroseconds(10);
//SPI.transfer(SDATAC); //Issue SDATAC
delayMicroseconds(10);
SPI.transfer(WREG | regAdress); // send 1st command byte, address of the register
SPI.transfer(0x00); // send 2nd command byte, write only one register
SPI.transfer(regValue); // write data (1 Byte) for the register
delayMicroseconds(10);
digitalWriteFast(_CS, HIGH);
//digitalWriteFast(_START, LOW);
if (regValue != ads12xx::GetRegisterValue(regAdress)) { //Check if write was succesfull
Serial.print("Write to Register 0x");
Serial.print(regAdress, HEX);
Serial.println(" failed!");
}
SPI.endTransaction();
}
}
//function to read a register value from the adc
//argument: adress for the register to read
unsigned long ads12xx::GetRegisterValue(uint8_t regAdress) {
uint8_t bufr;
//digitalWriteFast(_START, HIGH);
//waitforDRDY(_DRDY);
SPI.beginTransaction(SPISettings(SPI_SPEED, MSBFIRST, SPI_MODE1)); // initialize SPI with 4Mhz clock, MSB first, SPI Mode0
digitalWriteFast(_CS, LOW);
delayMicroseconds(10);
SPI.transfer(RREG | regAdress); // send 1st command byte, address of the register
SPI.transfer(0x00); // send 2nd command byte, read only one register
delayMicroseconds(10);
bufr = SPI.transfer(NOP); // read data of the register
delayMicroseconds(10);
digitalWriteFast(_CS, HIGH);
//digitalWriteFast(_START, LOW);
SPI.endTransaction();
return bufr;
}
/*
Sends a Command to the ADC
Like SELFCAL, GAIN, SYNC, WAKEUP
*/
void ads12xx::SendCMD(uint8_t cmd) {
ads12xx::waitforDRDY(_DRDY);
SPI.beginTransaction(SPISettings(SPI_SPEED, MSBFIRST, SPI_MODE1)); // initialize SPI with 4Mhz clock, MSB first, SPI Mode0
digitalWriteFast(_CS, LOW);
delayMicroseconds(10);
SPI.transfer(cmd);
delayMicroseconds(10);
digitalWriteFast(_CS, HIGH);
SPI.endTransaction();
}
// function to reset the adc
void ads12xx::Reset() {
SPI.beginTransaction(SPISettings(SPI_SPEED, MSBFIRST, SPI_MODE1)); // initialize SPI with clock, MSB first, SPI Mode1
digitalWriteFast(_CS, LOW);
delayMicroseconds(10);
SPI.transfer(RESET); //Reset
delay(2); //Minimum 0.6ms required for Reset to finish.
SPI.transfer(SDATAC); //Issue SDATAC
delayMicroseconds(100);
digitalWriteFast(_CS, HIGH);
SPI.endTransaction();
}