#ifndef vishnuADC #define vishnuADC #include "Arduino.h" #include <SPI.h> /** * Union representing the "config register" in 3 ways: * bits, word (16 bits) and nibbles (4 bits) * (See the datasheet [1] for more information) */ ///Union configuration register union Config { ///Structure of the config register of the ADS1118. (See datasheet [1]) struct { uint8_t reserved:1; ///< "Reserved" bit uint8_t noOperation:2; ///< "NOP" bits uint8_t pullUp:1; ///< "PULL_UP_EN" bit uint8_t sensorMode:1; ///< "TS_MODE" bit uint8_t rate:3; ///< "DR" bits uint8_t operatingMode:1;///< "MODE" bit uint8_t pga:3; ///< "PGA" bits uint8_t mux:3; ///< "MUX" bits uint8_t singleStart:1; ///< "SS" bit } bits; uint16_t word; ///< Representation in word (16-bits) format struct { uint8_t lsb; ///< Byte LSB uint8_t msb; ///< Byte MSB } byte; ///< Representation in bytes (8-bits) format }; /** * Class representing the ADS1118 sensor chip * @author Alvaro Salazar <alvaro@denkitronik.com> */ class ADS1118 { public: ADS1118(uint8_t io_pin_cs); ///< Constructor void begin(); ///< This method initialize the SPI port and the config register double getTemperature(); ///< Getting the temperature in degrees celsius from the internal sensor of the ADS1118 uint16_t getADCValue(uint8_t inputs);///< Getting a sample from the specified input double getMilliVolts(uint8_t inputs);//< Getting the millivolts from the specified inputs double getMilliVolts(); ///< Getting the millivolts from the settled inputs void decodeConfigRegister(union Config configRegister); ///< Decoding a configRegister structure and then print it out to the Serial port void setSamplingRate(uint8_t samplingRate);///< Setting the sampling rate specified in the config register void setFullScaleRange(uint8_t fsr);///< Setting the full scale range in the config register void setContinuousMode(); ///< Setting to continuous adquisition mode void setSingleShotMode(); ///< Setting to single shot adquisition and power down mode void disablePullup(); ///< Disabling the internal pull-up resistor of the DOUT pin void enablePullup(); ///< Enabling the internal pull-up resistor of the DOUT pin void setInputSelected(uint8_t input);///< Setting the inputs to be adquired in the config register. //Input multiplexer configuration selection for bits "MUX" //Differential inputs const uint8_t DIFF_0_1 = 0b000; ///< Differential input: Vin=A0-A1 const uint8_t DIFF_0_3 = 0b001; ///< Differential input: Vin=A0-A3 const uint8_t DIFF_1_3 = 0b010; ///< Differential input: Vin=A1-A3 const uint8_t DIFF_2_3 = 0b011; ///< Differential input: Vin=A2-A3 //Single ended inputs const uint8_t AIN_0 = 0b100; ///< Single ended input: Vin=A0 const uint8_t AIN_1 = 0b101; ///< Single ended input: Vin=A1 const uint8_t AIN_2 = 0b110; ///< Single ended input: Vin=A2 const uint8_t AIN_3 = 0b111; ///< Single ended input: Vin=A3 union Config configRegister; ///< Config register //Bit constants const long int SCLK = 4000000;///< ADS1118 SCLK frequency: 4000000 Hz Maximum for ADS1018 (4Mhz) // Used by "SS" bit const uint8_t START_NOW = 1; ///< Start of conversion in single-shot mode // Used by "TS_MODE" bit const uint8_t ADC_MODE = 0; ///< External (inputs) voltage reading mode const uint8_t TEMP_MODE = 1; ///< Internal temperature sensor reading mode // Used by "MODE" bit const uint8_t CONTINUOUS = 0; ///< Continuous conversion mode const uint8_t SINGLE_SHOT = 1; ///< Single-shot conversion and power down mode // Used by "PULL_UP_EN" bit const uint8_t PULLUP = 1; ///< Internal pull-up resistor enabled for DOUT ***DEFAULT const uint8_t NO_PULLUP = 0; ///< Internal pull-up resistor disabled // Used by "NOP" bits const uint8_t VALID_CFG = 0b01; ///< Data will be written to Config register const uint8_t NO_VALID_CFG= 0b00; ///< Data won't be written to Config register // Used by "Reserved" bit const uint8_t RESERVED = 1; ///< Its value is always 1, reserved /*Full scale range (FSR) selection by "PGA" bits. [Warning: this could increase the noise and the effective number of bits (ENOB). See tables above]*/ const uint8_t FSR_6144 = 0b000; ///< Range: ±6.144 v. LSB SIZE = 187.5μV const uint8_t FSR_4096 = 0b001; ///< Range: ±4.096 v. LSB SIZE = 125μV const uint8_t FSR_2048 = 0b010; ///< Range: ±2.048 v. LSB SIZE = 62.5μV ***DEFAULT const uint8_t FSR_1024 = 0b011; ///< Range: ±1.024 v. LSB SIZE = 31.25μV const uint8_t FSR_0512 = 0b100; ///< Range: ±0.512 v. LSB SIZE = 15.625μV const uint8_t FSR_0256 = 0b111; ///< Range: ±0.256 v. LSB SIZE = 7.8125μV /*Sampling rate selection by "DR" bits. [Warning: this could increase the noise and the effective number of bits (ENOB). See tables above]*/ const uint8_t RATE_8SPS = 0b000; ///< 8 samples/s, Tconv=125ms const uint8_t RATE_16SPS = 0b001; ///< 16 samples/s, Tconv=62.5ms const uint8_t RATE_32SPS = 0b010; ///< 32 samples/s, Tconv=31.25ms const uint8_t RATE_64SPS = 0b011; ///< 64 samples/s, Tconv=15.625ms const uint8_t RATE_128SPS = 0b100; ///< 128 samples/s, Tconv=7.8125ms const uint8_t RATE_250SPS = 0b101; ///< 250 samples/s, Tconv=4ms const uint8_t RATE_475SPS = 0b110; ///< 475 samples/s, Tconv=2.105ms const uint8_t RATE_860SPS = 0b111; ///< 860 samples/s, Tconv=1.163ms // const uint8_t RATE_3300SPS = 0b110; ///< 860 samples/s, Tconv=1.163ms private: uint8_t lastSensorMode=3; ///< Last sensor mode selected (ADC_MODE or TEMP_MODE or none) uint8_t cs; ///< Chip select pin (choose one) const float pgaFSR[8] = {6.144, 4.096, 2.048, 1.024, 0.512, 0.256, 0.256, 0.256}; const uint8_t CONV_TIME[8]={125, 63, 32, 16, 8, 4, 3, 2}; ///< Array containing the conversions time in ms }; #endif