diff options
Diffstat (limited to 'firmware/ADC.test.arduino/one')
| -rwxr-xr-x | firmware/ADC.test.arduino/one/libraries/vishnuADC.cpp | 51 | ||||
| -rwxr-xr-x | firmware/ADC.test.arduino/one/libraries/vishnuADC.h | 121 | ||||
| -rwxr-xr-x | firmware/ADC.test.arduino/one/one.ino | 42 |
3 files changed, 214 insertions, 0 deletions
diff --git a/firmware/ADC.test.arduino/one/libraries/vishnuADC.cpp b/firmware/ADC.test.arduino/one/libraries/vishnuADC.cpp new file mode 100755 index 0000000..01d6931 --- /dev/null +++ b/firmware/ADC.test.arduino/one/libraries/vishnuADC.cpp @@ -0,0 +1,51 @@ +#include "vishnuADC.h" +#include "Arduino.h" + +/** + * Constructor of the class + * @param io_pin_cs a byte indicating the pin to be use as the chip select pin (CS) + */ +ADS1118::ADS1118(uint8_t io_pin_cs) { + cs = io_pin_cs; +} + +/** + * This method initialize the SPI port and the config register + */ +void ADS1118::begin() { + pinMode(cs, OUTPUT); + digitalWrite(cs, HIGH); + SPI.begin(); + SPI.beginTransaction(SPISettings(SCLK, MSBFIRST, SPI_MODE1)); + configRegister.bits={RESERVED, VALID_CFG, PULLUP, ADC_MODE, RATE_8SPS, SINGLE_SHOT, FSR_0256, DIFF_0_1, START_NOW}; //Default values +} + +/** + * Getting the temperature in degrees celsius from the internal sensor of the ADS1118 + * @return A double (32bits) containing the temperature in degrees celsius of the internal sensor + */ +double ADS1118::getTemperature() { + uint16_t convRegister; + uint8_t dataMSB, dataLSB, configMSB, configLSB, count=0; + if(lastSensorMode==TEMP_MODE) + count=1; //Lucky you! We don't have to read twice the sensor + else + configRegister.bits.sensorMode=TEMP_MODE; //Sorry but we will have to read twice the sensor + do{ + digitalWrite(cs, LOW); + dataMSB = SPI.transfer(configRegister.byte.msb); + dataLSB = SPI.transfer(configRegister.byte.lsb); + configMSB = SPI.transfer(configRegister.byte.msb); + configLSB = SPI.transfer(configRegister.byte.lsb); + digitalWrite(cs, HIGH); + for(int i=0;i<CONV_TIME[configRegister.bits.rate];i++) //Lets wait the conversion time + delayMicroseconds(1000); + count++; + }while (count<=1); //We make two readings because the second reading is the temperature. + convRegister = ((dataMSB << 8) | (dataLSB))>>4; + if((convRegister<<2) >= 0x8000){ + convRegister=((~convRegister)>>2)+1; //Converting to right-justified and applying binary twos complement format + return (double)(convRegister*0.03125*-1); + } + return (double)convRegister*0.03125; +}
\ No newline at end of file diff --git a/firmware/ADC.test.arduino/one/libraries/vishnuADC.h b/firmware/ADC.test.arduino/one/libraries/vishnuADC.h new file mode 100755 index 0000000..33b0fb5 --- /dev/null +++ b/firmware/ADC.test.arduino/one/libraries/vishnuADC.h @@ -0,0 +1,121 @@ +#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 = 1000000;///< 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 diff --git a/firmware/ADC.test.arduino/one/one.ino b/firmware/ADC.test.arduino/one/one.ino new file mode 100755 index 0000000..862b0a7 --- /dev/null +++ b/firmware/ADC.test.arduino/one/one.ino @@ -0,0 +1,42 @@ +/** +* Basic Example for Arduino Library for Texas Instruments ADS1118 - 16-Bit Analog-to-Digital Converter with +* Internal Reference and Temperature Sensor +* +* @author Alvaro Salazar <alvaro@denkitronik.com> +* http://www.denkitronik.com +* +*/ + +#include "vishnuADC.h" +#include <SPI.h> + +//Definition of the Arduino pin to be used as the chip select pin (SPI CS pin). Example: pin 5 +#define CS 5 + +//Creating an ADS1118 object (object's name is ads1118) +ADS1118 ads1118(CS); + + +void setup(){ + Serial.begin(115200); + ads1118.begin(); //Initialize the ADS1118. Default setting: PULLUP RESISTOR, ADC MODE, RATE 8SPS, SINGLE SHOT, ±0.256V, DIFFERENTIAL AIN0-AIN1 + + /* Changing the sampling rate. RATE_8SPS, RATE_16SPS, RATE_32SPS, RATE_64SPS, RATE_128SPS, RATE_250SPS, RATE_475SPS, RATE_860SPS*/ + ads1118.setSamplingRate(ads1118.RATE_8SPS); + + /* Changing the input selected. Differential inputs: DIFF_0_1, DIFF_0_3, DIFF_1_3, DIFF_2_3. Single ended input: AIN_0, AIN_1, AIN_2, AIN_3*/ + ads1118.setInputSelected(ads1118.DIFF_0_1); + + /* Changing the full scale range. + * FSR_6144 (±6.144V)*, FSR_4096(±4.096V)*, FSR_2048(±2.048V), FSR_1024(±1.024V), FSR_0512(±0.512V), FSR_0256(±0.256V). + * (*) No more than VDD + 0.3 V must be applied to this device. + */ + ads1118.setFullScaleRange(ads1118.FSR_0256); +} + + +void loop(){ + Serial.println(String(ads1118.getTemperature(),6)+" C"); //Getting temperature of the internal sensor + //Serial.println(String(ads1118.getMilliVolts(),10)+"mV"); //Getting millivolts measured in the input selected + delay(200); //You can use a delay to save power. The ADS1118 will be in power down state during all the delay time. (Optional) +} |