jaewook shin
/
SCHMME_NIBP
SCH MME NIBP ref. code
Diff: ADS1115.h
- Revision:
- 0:8edd7b830280
- Child:
- 1:63bc0088a8ed
diff -r 000000000000 -r 8edd7b830280 ADS1115.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/ADS1115.h Mon Nov 09 00:33:42 2020 +0000 @@ -0,0 +1,169 @@ +#include <mbed.h> + +/*========================================================================= + I2C ADDRESS/BITS + -----------------------------------------------------------------------*/ + #define ADS1115_ADDRESS (0x49) // 100 1001 (ADDR = VDD) +/*=========================================================================*/ + +/*========================================================================= + CONVERSION DELAY (in mS) + -----------------------------------------------------------------------*/ + #define ADS1115_CONVERSIONDELAY (8) +/*=========================================================================*/ + +/*========================================================================= + POINTER REGISTER + -----------------------------------------------------------------------*/ + #define ADS1115_REG_POINTER_MASK (0x03) + #define ADS1115_REG_POINTER_CONVERT (0x00) + #define ADS1115_REG_POINTER_CONFIG (0x01) + #define ADS1115_REG_POINTER_LOWTHRESH (0x02) + #define ADS1115_REG_POINTER_HITHRESH (0x03) +/*=========================================================================*/ + +/*========================================================================= + CONFIG REGISTER + -----------------------------------------------------------------------*/ + #define ADS1115_REG_CONFIG_OS_MASK (0x8000) + #define ADS1115_REG_CONFIG_OS_SINGLE (0x8000) // Write: Set to start a single-conversion + #define ADS1115_REG_CONFIG_OS_BUSY (0x0000) // Read: Bit = 0 when conversion is in progress + #define ADS1115_REG_CONFIG_OS_NOTBUSY (0x8000) // Read: Bit = 1 when device is not performing a conversion + + #define ADS1115_REG_CONFIG_MUX_MASK (0x7000) + #define ADS1115_REG_CONFIG_MUX_DIFF_0_1 (0x0000) // Differential P = AIN0, N = AIN1 (default) + #define ADS1115_REG_CONFIG_MUX_DIFF_0_3 (0x1000) // Differential P = AIN0, N = AIN3 + #define ADS1115_REG_CONFIG_MUX_DIFF_1_3 (0x2000) // Differential P = AIN1, N = AIN3 + #define ADS1115_REG_CONFIG_MUX_DIFF_2_3 (0x3000) // Differential P = AIN2, N = AIN3 + #define ADS1115_REG_CONFIG_MUX_SINGLE_0 (0x4000) // Single-ended AIN0 + #define ADS1115_REG_CONFIG_MUX_SINGLE_1 (0x5000) // Single-ended AIN1 + #define ADS1115_REG_CONFIG_MUX_SINGLE_2 (0x6000) // Single-ended AIN2 + #define ADS1115_REG_CONFIG_MUX_SINGLE_3 (0x7000) // Single-ended AIN3 + + #define ADS1115_REG_CONFIG_PGA_MASK (0x0E00) + #define ADS1115_REG_CONFIG_PGA_6_144V (0x0000) // +/-6.144V range = Gain 2/3 + #define ADS1115_REG_CONFIG_PGA_4_096V (0x0200) // +/-4.096V range = Gain 1 + #define ADS1115_REG_CONFIG_PGA_2_048V (0x0400) // +/-2.048V range = Gain 2 (default) + #define ADS1115_REG_CONFIG_PGA_1_024V (0x0600) // +/-1.024V range = Gain 4 + #define ADS1115_REG_CONFIG_PGA_0_512V (0x0800) // +/-0.512V range = Gain 8 + #define ADS1115_REG_CONFIG_PGA_0_256V (0x0A00) // +/-0.256V range = Gain 16 + + #define ADS1115_REG_CONFIG_MODE_MASK (0x0100) + #define ADS1115_REG_CONFIG_MODE_CONTIN (0x0000) // Continuous conversion mode + #define ADS1115_REG_CONFIG_MODE_SINGLE (0x0100) // Power-down single-shot mode (default) + + #define ADS1115_REG_CONFIG_DR_MASK (0x00E0) + #define ADS1115_REG_CONFIG_DR_8SPS (0x0000) // 8SPS + #define ADS1115_REG_CONFIG_DR_16SPS (0x0020) // 16SPS + #define ADS1115_REG_CONFIG_DR_32SPS (0x0040) // 32SPS + #define ADS1115_REG_CONFIG_DR_64SPS (0x0060) // 64SPS + #define ADS1115_REG_CONFIG_DR_128SPS (0x0080) // 128SPS (default) + #define ADS1115_REG_CONFIG_DR_475SPS (0x00A0) // 475SPS + #define ADS1115_REG_CONFIG_DR_860SPS (0x00C0) // 860SPS + + #define ADS1115_REG_CONFIG_CMODE_MASK (0x0010) + #define ADS1115_REG_CONFIG_CMODE_TRAD (0x0000) // Traditional comparator with hysteresis (default) + #define ADS1115_REG_CONFIG_CMODE_WINDOW (0x0010) // Window comparator + + #define ADS1115_REG_CONFIG_CPOL_MASK (0x0008) + #define ADS1115_REG_CONFIG_CPOL_ACTVLOW (0x0000) // ALERT/RDY pin is low when active (default) + #define ADS1115_REG_CONFIG_CPOL_ACTVHI (0x0008) // ALERT/RDY pin is high when active + + #define ADS1115_REG_CONFIG_CLAT_MASK (0x0004) // Determines if ALERT/RDY pin latches once asserted + #define ADS1115_REG_CONFIG_CLAT_NONLAT (0x0000) // Non-latching comparator (default) + #define ADS1115_REG_CONFIG_CLAT_LATCH (0x0004) // Latching comparator + + #define ADS1115_REG_CONFIG_CQUE_MASK (0x0003) + #define ADS1115_REG_CONFIG_CQUE_1CONV (0x0000) // Assert ALERT/RDY after one conversions + #define ADS1115_REG_CONFIG_CQUE_2CONV (0x0001) // Assert ALERT/RDY after two conversions + #define ADS1115_REG_CONFIG_CQUE_4CONV (0x0002) // Assert ALERT/RDY after four conversions + #define ADS1115_REG_CONFIG_CQUE_NONE (0x0003) // Disable the comparator and put ALERT/RDY in high state (default) +/*=========================================================================*/ + +typedef enum { + GAIN_TWOTHIRDS = ADS1115_REG_CONFIG_PGA_6_144V, + GAIN_ONE = ADS1115_REG_CONFIG_PGA_4_096V, + GAIN_TWO = ADS1115_REG_CONFIG_PGA_2_048V, + GAIN_FOUR = ADS1115_REG_CONFIG_PGA_1_024V, + GAIN_EIGHT = ADS1115_REG_CONFIG_PGA_0_512V, + GAIN_SIXTEEN = ADS1115_REG_CONFIG_PGA_0_256V +} adsGain_t; + +uint8_t m_i2cAddress; +uint8_t m_conversionDelay; +uint8_t m_bitShift; +adsGain_t m_gain; +I2C* m_i2c; + +void ADS1115_Init(I2C* i2c, uint8_t i2cAddress) +{ + // shift 7 bit address 1 left: read expects 8 bit address, see I2C.h + m_i2cAddress = i2cAddress << 1; + m_conversionDelay = ADS1115_CONVERSIONDELAY; + m_gain = GAIN_TWOTHIRDS; /* +/- 6.144V range (limited to VDD +0.3V max!) */ + m_i2c = i2c; +} + +uint16_t ADS1115_readRegister(uint8_t i2cAddress, uint8_t reg) +{ + char data[2]; + data[0] = reg; // temporary use this to send address to conversion register + m_i2c->write(i2cAddress, data, 1); + m_i2c->read(i2cAddress, data, 2); + return (data[0] << 8 | data [1]); +} + +void ADS1115_writeRegister(uint8_t i2cAddress, uint8_t reg, uint16_t value) +{ + char cmd[3]; + cmd[0] = (char)reg; + cmd[1] = (char)(value>>8); + cmd[2] = (char)(value & 0xFF); + m_i2c->write(i2cAddress, cmd, 3); +} + + +uint16_t ADS1115_setConti_ADC_SingleEnded(uint8_t channel) +{ + if (channel > 3) { + return 0; + } + + // Start with default values + uint16_t config = ADS1115_REG_CONFIG_CQUE_1CONV | // Assert ALERT/RDY after one conversions + ADS1115_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val) + ADS1115_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val) + ADS1115_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val) + ADS1115_REG_CONFIG_DR_475SPS | // 475SPS + ADS1115_REG_CONFIG_MODE_CONTIN; // Countinuous-conversion mode + + // Set PGA/voltage range + config |= m_gain; + + // Set single-ended input channel + switch (channel) { + case (0): + config |= ADS1115_REG_CONFIG_MUX_SINGLE_0; + break; + case (1): + config |= ADS1115_REG_CONFIG_MUX_SINGLE_1; + break; + case (2): + config |= ADS1115_REG_CONFIG_MUX_SINGLE_2; + break; + case (3): + config |= ADS1115_REG_CONFIG_MUX_SINGLE_3; + break; + } + ADS1115_writeRegister(m_i2cAddress, ADS1115_REG_POINTER_LOWTHRESH, 0x7fff); + ADS1115_writeRegister(m_i2cAddress, ADS1115_REG_POINTER_HITHRESH, 0x8000); + ADS1115_writeRegister(m_i2cAddress, ADS1115_REG_POINTER_CONFIG, config); + + return 0; +} + +int16_t ADS1115_getConti_ADC_SingleEnded() +{ + uint16_t res = ADS1115_readRegister(m_i2cAddress, ADS1115_REG_POINTER_CONVERT); + return (int16_t)res; +} \ No newline at end of file