# The MIT License (MIT)
#
# Copyright (c) 2016 Radomir Dopieralski (@deshipu), 2017 Robert Hammelrath (@robert-hh)
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#
import utime as time
_REGISTER_MASK = const(0x03)
_REGISTER_CONVERT = const(0x00)
_REGISTER_CONFIG = const(0x01)
_REGISTER_LOWTHRESH = const(0x02)
_REGISTER_HITHRESH = const(0x03)
_OS_MASK = const(0x8000)
_OS_SINGLE = const(0x8000) # Write: Set to start a single-conversion
_OS_BUSY = const(0x0000) # Read: Bit=0 when conversion is in progress
_OS_NOTBUSY = const(0x8000) # Read: Bit=1 when device is not performing a conversion
_MUX_MASK = const(0x7000)
_MUX_DIFF_0_1 = const(0x0000) # Differential P = AIN0, N = AIN1 (default)
_MUX_DIFF_0_3 = const(0x1000) # Differential P = AIN0, N = AIN3
_MUX_DIFF_1_3 = const(0x2000) # Differential P = AIN1, N = AIN3
_MUX_DIFF_2_3 = const(0x3000) # Differential P = AIN2, N = AIN3
_MUX_SINGLE_0 = const(0x4000) # Single-ended AIN0
_MUX_SINGLE_1 = const(0x5000) # Single-ended AIN1
_MUX_SINGLE_2 = const(0x6000) # Single-ended AIN2
_MUX_SINGLE_3 = const(0x7000) # Single-ended AIN3
_PGA_MASK = const(0x0E00)
_PGA_6_144V = const(0x0000) # +/-6.144V range = Gain 2/3
_PGA_4_096V = const(0x0200) # +/-4.096V range = Gain 1
_PGA_2_048V = const(0x0400) # +/-2.048V range = Gain 2 (default)
_PGA_1_024V = const(0x0600) # +/-1.024V range = Gain 4
_PGA_0_512V = const(0x0800) # +/-0.512V range = Gain 8
_PGA_0_256V = const(0x0A00) # +/-0.256V range = Gain 16
_MODE_MASK = const(0x0100)
_MODE_CONTIN = const(0x0000) # Continuous conversion mode
_MODE_SINGLE = const(0x0100) # Power-down single-shot mode (default)
_DR_MASK = const(0x00E0) # Values ADS1015/ADS1115
_DR_128SPS = const(0x0000) # 128 /8 samples per second
_DR_250SPS = const(0x0020) # 250 /16 samples per second
_DR_490SPS = const(0x0040) # 490 /32 samples per second
_DR_920SPS = const(0x0060) # 920 /64 samples per second
_DR_1600SPS = const(0x0080) # 1600/128 samples per second (default)
_DR_2400SPS = const(0x00A0) # 2400/250 samples per second
_DR_3300SPS = const(0x00C0) # 3300/475 samples per second
_DR_860SPS = const(0x00E0) # - /860 samples per Second
_CMODE_MASK = const(0x0010)
_CMODE_TRAD = const(0x0000) # Traditional comparator with hysteresis (default)
_CMODE_WINDOW = const(0x0010) # Window comparator
_CPOL_MASK = const(0x0008)
_CPOL_ACTVLOW = const(0x0000) # ALERT/RDY pin is low when active (default)
_CPOL_ACTVHI = const(0x0008) # ALERT/RDY pin is high when active
_CLAT_MASK = const(0x0004) # Determines if ALERT/RDY pin latches once asserted
_CLAT_NONLAT = const(0x0000) # Non-latching comparator (default)
_CLAT_LATCH = const(0x0004) # Latching comparator
_CQUE_MASK = const(0x0003)
_CQUE_1CONV = const(0x0000) # Assert ALERT/RDY after one conversions
_CQUE_2CONV = const(0x0001) # Assert ALERT/RDY after two conversions
_CQUE_4CONV = const(0x0002) # Assert ALERT/RDY after four conversions
_CQUE_NONE = const(0x0003) # Disable the comparator and put ALERT/RDY in high state (default)
_GAINS = (
_PGA_6_144V, # 2/3x
_PGA_4_096V, # 1x
_PGA_2_048V, # 2x
_PGA_1_024V, # 4x
_PGA_0_512V, # 8x
_PGA_0_256V # 16x
)
_CHANNELS = {
(0, None): _MUX_SINGLE_0,
(1, None): _MUX_SINGLE_1,
(2, None): _MUX_SINGLE_2,
(3, None): _MUX_SINGLE_3,
(0, 1): _MUX_DIFF_0_1,
(0, 3): _MUX_DIFF_0_3,
(1, 3): _MUX_DIFF_1_3,
(2, 3): _MUX_DIFF_2_3,
}
_RATES = (
_DR_128SPS, # 128/8 samples per second
_DR_250SPS, # 250/16 samples per second
_DR_490SPS, # 490/32 samples per second
_DR_920SPS, # 920/64 samples per second
_DR_1600SPS, # 1600/128 samples per second (default)
_DR_2400SPS, # 2400/250 samples per second
_DR_3300SPS, # 3300/475 samples per second
_DR_860SPS # - /860 samples per Second
)
class ADS1115:
def __init__(self, i2c, address=0x48, gain=1):
self.i2c = i2c
self.address = address
self.gain = gain #
self.temp1 = bytearray(1)
self.temp2 = bytearray(2)
self.temp3 = bytearray(3)
def _write_register(self, register, value):
self.temp3[0] = register
self.temp3[1] = value >> 8
self.temp3[2] = value & 0xff
self.i2c.writeto(self.address, self.temp3)
def _read_register(self, register):
self.temp1[0] = register
self.i2c.writeto(self.address, self.temp1)
self.i2c.readfrom_into(self.address, self.temp2)
return (self.temp2[0] << 8) | self.temp2[1]
def set_conv(self, rate, channel1, channel2 = None):
"""Set mode for read_rev"""
self.mode = (_CQUE_NONE | _CLAT_NONLAT |
_CPOL_ACTVLOW | _CMODE_TRAD | _RATES[rate] | _MODE_SINGLE |
_OS_SINGLE | _GAINS[self.gain] | _CHANNELS[(channel1, channel2)])
def read(self, rate, channel1, channel2 = None):
"""Read voltage between a channel and GND. Time depends on conversion rate."""
self._write_register(_REGISTER_CONFIG, (_CQUE_NONE | _CLAT_NONLAT |
_CPOL_ACTVLOW | _CMODE_TRAD | _RATES[rate] | _MODE_SINGLE |
_OS_SINGLE | _GAINS[self.gain] | _CHANNELS[(channel1, channel2)]))
while not self._read_register(_REGISTER_CONFIG) & _OS_NOTBUSY:
time.sleep_ms(1)
res = self._read_register(_REGISTER_CONVERT)
return res if res < 32768 else res - 65536
def read_rev(self):
"""Read voltage between a channel and GND. and then start the next conversion."""
res = self._read_register(_REGISTER_CONVERT)
self._write_register(_REGISTER_CONFIG, self.mode)
return res if res < 32768 else res - 65536
def alert_start(self, rate, channe1l, channel2 = None, threshold_high = 0x4000):
"""Start continuous measurement, set ALERT pin on threshold."""
self._write_register(_REGISTER_LOWTHRESH, 0)
self._write_register(_REGISTER_HITHRESH, threshold_high)
self._write_register(_REGISTER_CONFIG, _CQUE_1CONV | _CLAT_LATCH |
_CPOL_ACTVLOW | _CMODE_TRAD | _RATES[rate] |
_MODE_CONTIN | _GAINS[self.gain] | _CHANNELS[(channel1, channel2)])
def conversion_start(self, rate, channel1, channel2 = None):
"""Start continuous measurement, trigger on ALERT/RDY pin."""
self._write_register(_REGISTER_LOWTHRESH, 0)
self._write_register(_REGISTER_HITHRESH, 0x8000)
self._write_register(_REGISTER_CONFIG, _CQUE_1CONV | _CLAT_NONLAT |
_CPOL_ACTVLOW | _CMODE_TRAD | _RATES[rate] |
_MODE_CONTIN | _GAINS[self.gain] | _CHANNELS[(channel1, channel2)])
def alert_read(self):
"""Get the last reading from the continuous measurement."""
res = self._read_register(_REGISTER_CONVERT)
return res if res < 32768 else res - 65536
class ADS1015(ADS1115):
def __init__(self, i2c, address=0x48):
return super().__init__(i2c, address)
def read(self, rate, channel1, channel2 = None):
return super().read(rate, channel1, channel2) >> 4
def alert_start(self, rate, channel1, channel2 = None, threshold = 0x400):
return super().alert_start(rate, channel1, channel2, threshold << 4)
def alert_read(self):
return super().alert_read() >> 4