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Arnaud WATLET authored6a91371a
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import datetime
import adafruit_ads1x15.ads1115 as ads # noqa
from adafruit_ads1x15.analog_in import AnalogIn # noqa
from adafruit_ads1x15.ads1x15 import Mode # noqa
from adafruit_mcp230xx.mcp23008 import MCP23008 # noqa
from digitalio import Direction # noqa
from busio import I2C # noqa
from ohmpi.hardware_components.mb_2023_0_X import Tx as Tx_mb_2023
from ohmpi.hardware_components.mb_2023_0_X import Rx as Rx_mb_2023
# hardware characteristics and limitations
# voltages are given in mV, currents in mA, sampling rates in Hz and data_rate in S/s
SPECS = {'rx': {'sampling_rate': {'min': 2., 'default': 10., 'max': 100.},
'data_rate': {'default': 860.},
'bias': {'min': -5000., 'default': 0., 'max': 5000.},
'coef_p2': {'default': 1.00},
'mcp_address': {'default': 0x21},
'ads_address': {'default': 0x49},
'voltage_min': {'default': 10.0},
'vmn_hardware_offset' : {'default': 2500.},
},
'tx': {'adc_voltage_min': {'default': 10.}, # Minimum voltage value used in vmin strategy
'adc_voltage_max': {'default': 4500.}, # Maximum voltage on ads1115 used to measure current
'voltage_max': {'min': 0., 'default': 12., 'max': 12.}, # Maximum input voltage
'data_rate': {'default': 860.},
'mcp_address': {'default': 0x27},
'ads_address': {'default': 0x48},
'compatible_power_sources': {'default': 'pwr_batt', 'others' : ['dps5005']},
'r_shunt': {'min': 0., 'default': 2.},
'activation_delay': {'default': 0.010}, # Max turn on time of OMRON G5LE-1 5VDC relays
'release_delay': {'default': 0.005}, # Max turn off time of OMRON G5LE-1 5VDC relays = 1ms
}}
# TODO: move low_battery spec in pwr
def _ads_1115_gain_auto(channel): # Make it a class method ?
"""Automatically sets the gain on a channel
Parameters
----------
channel : ads.ADS1x15
Instance of ADS where voltage is measured.
Returns
-------
gain : float
Gain to be applied on ADS1115.
"""
gain = 2 / 3
if (abs(channel.voltage) < 2.048) and (abs(channel.voltage) >= 1.024):
gain = 2
elif (abs(channel.voltage) < 1.024) and (abs(channel.voltage) >= 0.512):
gain = 4
elif (abs(channel.voltage) < 0.512) and (abs(channel.voltage) >= 0.256):
gain = 8
elif abs(channel.voltage) < 0.256:
gain = 16
return gain
class Tx(Tx_mb_2023):
def __init__(self, **kwargs):
super().__init__(**kwargs)
# I2C connexion to MCP23008, for current injection
self.mcp_board = MCP23008(self.connection, address=kwargs['mcp_address'])
# Initialize LEDs
self.pin4 = self.mcp_board.get_pin(4) # Ohmpi_run
self.pin4.direction = Direction.OUTPUT
self.pin4.value = True
self.pin6 = self.mcp_board.get_pin(6)
self.pin6.direction = Direction.OUTPUT
self.pin6.value = False
self.exec_logger.event(f'{self.board_name}\ttx_init\tend\t{datetime.datetime.utcnow()}')
def inject(self, polarity=1, injection_duration=None):
# add leds?
self.pin6.value=True
Tx_mb_2023.inject(self, polarity=polarity, injection_duration=injection_duration)
self.pin6.value = False
class Rx(Rx_mb_2023):
def __init__(self, **kwargs):
super().__init__(**kwargs)
# I2C connexion to MCP23008, for voltage
self.mcp_board = MCP23008(self.connection, address=kwargs['mcp_address'])
# ADS1115 for voltage measurement (MN)
self._coef_p2 = 1.
# Define default DG411 gain
self._dg411_gain = 1/2
# Define pins for DG411
self.pin_DG0 = self.mcp_board.get_pin(0)
self.pin_DG0.direction = Direction.OUTPUT
self.pin_DG1 = self.mcp_board.get_pin(1)
self.pin_DG1.direction = Direction.OUTPUT
self.pin_DG2 = self.mcp_board.get_pin(2)
self.pin_DG2.direction = Direction.OUTPUT
self.pin_DG0.value = True # open
self.pin_DG1.value = True # open gain 1 inactive
self.pin_DG2.value = False # close gain 0.5 active
self.gain = 1/3
# TODO: try to only log this event and not the one created by super()
self.exec_logger.event(f'{self.board_name}\trx_init\tend\t{datetime.datetime.utcnow()}')
def _dg411_gain_auto(self):
if self.voltage < self._vmn_hardware_offset :
self._dg411_gain = 1.
else:
self._dg411_gain = 1/2
@property
def gain(self):
return self._adc_gain*self._dg411_gain
@gain.setter
def gain(self, value):
assert value in [1/3, 2/3]
self._dg411_gain = value / self._adc_gain
if self._dg411_gain == 1.:
self.pin_DG1.value = False # closed gain 1 active
self.pin_DG2.value = True # open gain 0.5 inactive
elif self._dg411_gain == 1/2:
self.pin_DG1.value = True # closed gain 1 active
self.pin_DG2.value = False # open gain 0.5 inactive
def gain_auto(self):
self._dg411_gain_auto()
@property
def voltage(self):
""" Gets the voltage VMN in Volts
"""
self.exec_logger.event(f'{self.board_name}\trx_voltage\tbegin\t{datetime.datetime.utcnow()}')
u = (AnalogIn(self._ads_voltage, ads.P0).voltage * self._coef_p2 * 1000. - self._vmn_hardware_offset) / self._dg411_gain - self._bias # TODO: check how to handle bias and _vmn_hardware_offset
self.exec_logger.event(f'{self.board_name}\trx_voltage\tend\t{datetime.datetime.utcnow()}')
return u