# -*- coding: utf-8 -*-
"""
created on January 6, 2020.
Update March 2022
Ohmpi.py is a program to control a low-cost and open hardware resistivity meter OhmPi that has been developed by
Rémi CLEMENT (INRAE),Vivien DUBOIS (INRAE), Hélène GUYARD (IGE), Nicolas FORQUET (INRAE), Yannick FARGIER (IFSTTAR)
Olivier KAUFMANN (UMONS) and Guillaume BLANCHY (ILVO).
"""
import os
import io
import json
import numpy as np
import csv
import time
from datetime import datetime
from termcolor import colored
import threading
from logging_setup import setup_loggers
import minimalmodbus # for programmable power supply
from copy import deepcopy
# from mqtt_setup import mqtt_client_setup
# finish import (done only when class is instantiated as some libs are only available on arm64 platform)
try:
import board # noqa
import busio # noqa
import adafruit_tca9548a # noqa
import adafruit_ads1x15.ads1115 as ads # noqa
from adafruit_ads1x15.analog_in import AnalogIn # noqa
from adafruit_mcp230xx.mcp23008 import MCP23008 # noqa
from adafruit_mcp230xx.mcp23017 import MCP23017 # noqa
import digitalio # noqa
from digitalio import Direction # noqa
from gpiozero import CPUTemperature # noqa
arm64_imports = True
except ImportError as error:
print(colored(f'Import error: {error}', 'yellow'))
arm64_imports = False
except Exception as error:
print(colored(f'Unexpected error: {error}', 'red'))
exit()
class OhmPi(object):
"""Create the main OhmPi object.
Parameters
----------
config : str, optional
Path to the .json configuration file.
sequence : str, optional
Path to the .txt where the sequence is read. By default, a 1 quadrupole
sequence: 1, 2, 3, 4 is used.
"""
def __init__(self, config=None, sequence=None, mqtt=False, on_pi=None, idps=False):
# flags and attributes
if on_pi is None:
_, on_pi = OhmPi.get_platform()
self.sequence = sequence
self.on_pi = on_pi # True if run from the RaspberryPi with the hardware, otherwise False for random data
self.status = 'idle' # either running or idle
self.run = False # flag is True when measuring
self.thread = None # contains the handle for the thread taking the measurement
self.path = 'data/' # where to save the .csv
# set loggers
config_exec_logger, _, config_data_logger, _, _ = setup_loggers(mqtt=mqtt) # TODO: add SOH
self.data_logger = config_data_logger
self.exec_logger = config_exec_logger
self.soh_logger = None
print('Loggers:')
print(colored(f'Exec logger {self.exec_logger.handlers if self.exec_logger is not None else "None"}', 'blue'))
print(colored(f'Data logger {self.data_logger.handlers if self.data_logger is not None else "None"}', 'blue'))
print(colored(f'SOH logger {self.soh_logger.handlers if self.soh_logger is not None else "None"}', 'blue'))
# read in hardware parameters (settings.py)
self._read_hardware_parameters()
# default acquisition parameters
self.pardict = {
'injection_duration': 0.2,
'nbr_meas': 100,
'sequence_delay': 1,
'nb_stack': 1,
'export_path': 'data/measurement.csv'
}
# read in acquisition parameters
if config is not None:
self._read_acquisition_parameters(config)
self.exec_logger.debug('Initialized with configuration:' + str(self.pardict))
# read quadrupole sequence
if sequence is None:
self.sequence = np.array([[1, 4, 2, 3]])
else:
self.read_quad(sequence)
self.idps = idps # flag to use dps for injection or not
# connect to components on the OhmPi board
if self.on_pi:
# activation of I2C protocol
self.i2c = busio.I2C(board.SCL, board.SDA) # noqa
# I2C connexion to MCP23008, for current injection
self.mcp = MCP23008(self.i2c, address=0x20)
# ADS1115 for current measurement (AB)
self.ads_current = ads.ADS1115(self.i2c, gain=2 / 3, data_rate=128, address=0x49)
# ADS1115 for voltage measurement (MN)
self.ads_voltage = ads.ADS1115(self.i2c, gain=2 / 3, data_rate=128, address=0x48)
# current injection module
if self.idps:
self.DPS = minimalmodbus.Instrument(port='/dev/ttyUSB0', slaveaddress=1) # port name, slave address (in decimal)
self.DPS.serial.baudrate = 9600 # Baud rate 9600 as listed in doc
self.DPS.serial.bytesize = 8 #
self.DPS.serial.timeout = 1 # greater than 0.5 for it to work
self.DPS.debug = False #
self.DPS.serial.parity = 'N' # No parity
self.DPS.mode = minimalmodbus.MODE_RTU # RTU mode
self.DPS.write_register(0x0001, 40, 0) # max current allowed (36 mA for relays)
# (last number) 0 is for mA, 3 is for A
# injection courant and measure (TODO check if it works, otherwise back in run_measurement())
self.pin0 = self.mcp.get_pin(0)
self.pin0.direction = Direction.OUTPUT
self.pin0.value = False
self.pin1 = self.mcp.get_pin(1)
self.pin1.direction = Direction.OUTPUT
self.pin1.value = False
def _read_acquisition_parameters(self, config):
"""Read acquisition parameters.
Parameters can be:
- nb_electrodes (number of electrode used, if 4, no MUX needed)
- injection_duration (in seconds)
- nbr_meas (total number of times the sequence will be run)
- sequence_delay (delay in second between each sequence run)
- nb_stack (number of stack for each quadrupole measurement)
- export_path (path where to export the data, timestamp will be added to filename)
Parameters
----------
config : str
Path to the .json or dictionary.
"""
if isinstance(config, dict):
self.pardict.update(config)
else:
with open(config) as json_file:
dic = json.load(json_file)
self.pardict.update(dic)
self.exec_logger.debug('Acquisition parameters updated: ' + str(self.pardict))
def _read_hardware_parameters(self):
"""Read hardware parameters from config.py
"""
from config import OHMPI_CONFIG
self.id = OHMPI_CONFIG['id'] # ID of the OhmPi
self.r_shunt = OHMPI_CONFIG['R_shunt'] # reference resistance value in ohm
self.Imax = OHMPI_CONFIG['Imax'] # maximum current
self.exec_logger.warning(f'The maximum current cannot be higher than {self.Imax} mA')
self.coef_p2 = OHMPI_CONFIG['coef_p2'] # slope for current conversion for ads.P2, measurement in V/V
self.coef_p3 = OHMPI_CONFIG['coef_p3'] # slope for current conversion for ads.P3, measurement in V/V
# self.offset_p2 = OHMPI_CONFIG['offset_p2'] parameter removed
# self.offset_p3 = OHMPI_CONFIG['offset_p3'] parameter removed
self.nb_samples = OHMPI_CONFIG['integer'] # number of samples measured for each stack
self.version = OHMPI_CONFIG['version'] # hardware version
self.max_elec = OHMPI_CONFIG['max_elec'] # maximum number of electrodes
self.board_address = OHMPI_CONFIG['board_address']
self.exec_logger.debug(f'OHMPI_CONFIG = {str(OHMPI_CONFIG)}')
@staticmethod
def find_identical_in_line(quads):
"""Find quadrupole which where A and B are identical.
If A and B are connected to the same relay, the Pi burns (short-circuit).
Parameters
----------
quads : numpy.ndarray
List of quadrupoles of shape nquad x 4 or 1D vector of shape nquad.
Returns
-------
output : 1D array of int
List of index of rows where A and B are identical.
"""
# TODO is this needed for M and N?
# if we have a 1D array (so only 1 quadrupole), make it 2D
if len(quads.shape) == 1:
quads = quads[None, :]
output = np.where(quads[:, 0] == quads[:, 1])[0]
# output = []
# if array_object.ndim == 1:
# temp = np.zeros(4)
# for i in range(len(array_object)):
# temp[i] = np.count_nonzero(array_object == array_object[i])
# if any(temp > 1):
# output.append(0)
# else:
# for i in range(len(array_object[:,1])):
# temp = np.zeros(len(array_object[1,:]))
# for j in range(len(array_object[1,:])):
# temp[j] = np.count_nonzero(array_object[i,:] == array_object[i,j])
# if any(temp > 1):
# output.append(i)
return output
@staticmethod
def get_platform():
"""Get platform name and check if it is a raspberry pi
Returns
=======
str, bool
name of the platform on which the code is running, boolean that is true if the platform is a raspberry pi"""
platform = 'unknown'
on_pi = False
try:
with io.open('/sys/firmware/devicetree/base/model', 'r') as f:
platform = f.read().lower()
if 'raspberry pi' in platform:
on_pi = True
except FileNotFoundError:
pass
return platform, on_pi
def read_quad(self, filename):
"""Read quadrupole sequence from file.
Parameters
----------
filename : str
Path of the .csv or .txt file with A, B, M and N electrodes.
Electrode index start at 1.
Returns
-------
output : numpy.ndarray
Array of shape (number quadrupoles * 4).
"""
output = np.loadtxt(filename, delimiter=" ", dtype=int) # load quadrupole file
# locate lines where the electrode index exceeds the maximum number of electrodes
test_index_elec = np.array(np.where(output > self.max_elec))
# locate lines where electrode A == electrode B
test_same_elec = self.find_identical_in_line(output)
# if statement with exit cases (TODO rajouter un else if pour le deuxième cas du ticket #2)
if test_index_elec.size != 0:
for i in range(len(test_index_elec[0, :])):
self.exec_logger.error(f'An electrode index at line {str(test_index_elec[0, i] + 1)} '
f'exceeds the maximum number of electrodes')
# sys.exit(1)
output = None
elif len(test_same_elec) != 0:
for i in range(len(test_same_elec)):
self.exec_logger.error(f'An electrode index A == B detected at line {str(test_same_elec[i] + 1)}')
# sys.exit(1)
output = None
if output is not None:
self.exec_logger.debug('Sequence of {:d} quadrupoles read.'.format(output.shape[0]))
self.sequence = output
def switch_mux(self, electrode_nr, state, role):
"""Select the right channel for the multiplexer cascade for a given electrode.
Parameters
----------
electrode_nr : int
Electrode index to be switched on or off.
state : str
Either 'on' or 'off'.
role : str
Either 'A', 'B', 'M' or 'N', so we can assign it to a MUX board.
"""
if self.sequence.max() <= 4: # only 4 electrodes so no MUX
pass
else:
# choose with MUX board
tca = adafruit_tca9548a.TCA9548A(self.i2c, self.board_address[role])
# find I2C address of the electrode and corresponding relay
# considering that one MCP23017 can cover 16 electrodes
electrode_nr = electrode_nr - 1 # switch to 0 indexing
i2c_address = 7 - electrode_nr // 16 # quotient without rest of the division
relay_nr = electrode_nr - (electrode_nr // 16) * 16
relay_nr = relay_nr + 1 # switch back to 1 based indexing
if i2c_address is not None:
# select the MCP23017 of the selected MUX board
mcp2 = MCP23017(tca[i2c_address])
mcp2.get_pin(relay_nr - 1).direction = digitalio.Direction.OUTPUT
if state == 'on':
mcp2.get_pin(relay_nr - 1).value = True
else:
mcp2.get_pin(relay_nr - 1).value = False
self.exec_logger.debug(f'Switching relay {relay_nr} {state} for electrode {electrode_nr}')
else:
self.exec_logger.warning(f'Unable to address electrode nr {electrode_nr}')
def switch_mux_on(self, quadrupole):
""" Switch on multiplexer relays for given quadrupole.
Parameters
----------
quadrupole : list of 4 int
List of 4 integers representing the electrode numbers.
"""
roles = ['A', 'B', 'M', 'N']
# another check to be sure A != B
if quadrupole[0] != quadrupole[1]:
for i in range(0, 4):
if quadrupole[i] > 0:
self.switch_mux(quadrupole[i], 'on', roles[i])
else:
self.exec_logger.error('A == B -> short circuit risk detected!')
def switch_mux_off(self, quadrupole):
""" Switch off multiplexer relays for given quadrupole.
Parameters
----------
quadrupole : list of 4 int
List of 4 integers representing the electrode numbers.
"""
roles = ['A', 'B', 'M', 'N']
for i in range(0, 4):
if quadrupole[i] > 0:
self.switch_mux(quadrupole[i], 'off', roles[i])
def reset_mux(self):
"""Switch off all multiplexer relays."""
roles = ['A', 'B', 'M', 'N']
for i in range(0, 4):
for j in range(1, self.max_elec + 1):
self.switch_mux(j, 'off', roles[i])
self.exec_logger.debug('All MUX switched off.')
def gain_auto(self, channel):
""" Automatically set the gain on a channel
Parameters
----------
channel:
Returns
-------
float
"""
gain = 2 / 3
if (abs(channel.voltage) < 2.040) and (abs(channel.voltage) >= 1.023):
gain = 2
elif (abs(channel.voltage) < 1.023) and (abs(channel.voltage) >= 0.508):
gain = 4
elif (abs(channel.voltage) < 0.508) and (abs(channel.voltage) >= 0.250):
gain = 8
elif abs(channel.voltage) < 0.256:
gain = 16
self.exec_logger.debug(f'Setting gain to {gain}')
return gain
def compute_tx_volt(self, best_tx_injtime=0.1, strategy='vmax', tx_volt=5):
"""Estimating best Tx voltage based on different strategy.
At first a half-cycle is made for a short duration with a fixed
known voltage. This gives us Iab and Rab. We also measure Vmn.
A constant c = vmn/iab is computed (only depends on geometric
factor and ground resistivity, that doesn't change during a
quadrupole). Then depending on the strategy, we compute which
vab to inject to reach the minimum/maximum Iab current or
min/max Vmn.
This function also compute the polarity on Vmn (on which pin
of the ADS1115 we need to measure Vmn to get the positive value).
Parameters
----------
best_tx_injtime : float, optional
Time in milliseconds for the half-cycle used to compute Rab.
strategy : str, optional
Either:
- vmin : compute Vab to reach a minimum Iab and Vmn
- vmax : compute Vab to reach a maximum Iab and Vmn
- constant : apply given Vab
tx_volt : float, optional
Voltage apply to try to guess the best voltage. 5 V applied
by default. If strategy "constant" is chosen, constant voltage
to applied is "tx_volt".
Returns
-------
vab : float
Proposed Vab according to the given strategy.
polarity : int
Either 1 or -1 to know on which pin of the ADS the Vmn is measured.
"""
# hardware limits
voltage_min = 10 # mV
voltage_max = 4500
current_min = voltage_min / (self.r_shunt * 50) # mA
current_max = voltage_max / (self.r_shunt * 50)
tx_max = 40 # volt
# check of volt
volt = tx_volt
if volt > tx_max:
print('sorry, cannot inject more than 40 V, set it back to 5 V')
volt = 5
# redefined the pin of the mcp (needed when relays are connected)
self.pin0 = self.mcp.get_pin(0)
self.pin0.direction = Direction.OUTPUT
self.pin0.value = False
self.pin1 = self.mcp.get_pin(1)
self.pin1.direction = Direction.OUTPUT
self.pin1.value = False
# select a polarity to start with
self.pin0.value = True
self.pin1.value = False
# set voltage for test
self.DPS.write_register(0x0000, volt, 2)
self.DPS.write_register(0x09, 1) # DPS5005 on
time.sleep(best_tx_injtime) # inject for given tx time
# autogain
self.ads_current = ads.ADS1115(self.i2c, gain=2/3, data_rate=860, address=0x49)
self.ads_voltage = ads.ADS1115(self.i2c, gain=2/3, data_rate=860, address=0x48)
print('current P0', AnalogIn(self.ads_current, ads.P0).voltage)
print('voltage P0', AnalogIn(self.ads_voltage, ads.P0).voltage)
print('voltage P2', AnalogIn(self.ads_voltage, ads.P2).voltage)
gain_current = self.gain_auto(AnalogIn(self.ads_current, ads.P0))
gain_voltage0 = self.gain_auto(AnalogIn(self.ads_voltage, ads.P0))
gain_voltage2 = self.gain_auto(AnalogIn(self.ads_voltage, ads.P2))
gain_voltage = np.min([gain_voltage0, gain_voltage2])
print('gain current: {:.3f}, gain voltage: {:.3f}'.format(gain_current, gain_voltage))
self.ads_current = ads.ADS1115(self.i2c, gain=gain_current, data_rate=860, address=0x49)
self.ads_voltage = ads.ADS1115(self.i2c, gain=gain_voltage, data_rate=860, address=0x48)
# we measure the voltage on both A0 and A2 to guess the polarity
I = (AnalogIn(self.ads_current, ads.P0).voltage) * 1000/50/self.r_shunt # measure current
U0 = AnalogIn(self.ads_voltage, ads.P0).voltage * 1000 # measure voltage
U2 = AnalogIn(self.ads_voltage, ads.P2).voltage * 1000
print('I (mV)', I*50*self.r_shunt)
print('I (mA)', I)
print('U0 (mV)', U0)
print('U2 (mV)', U2)
# check polarity
polarity = 1 # by default, we guessed it right
vmn = U0
if U0 < 0: # we guessed it wrong, let's use a correction factor
polarity = -1
vmn = U2
print('polarity', polarity)
# compute constant
c = vmn / I
Rab = (volt * 1000) / I
print('Rab', Rab)
# implement different strategy
if strategy == 'vmax':
vmn_max = c * current_max
if vmn_max < voltage_max and vmn_max > voltage_min:
vab = current_max * Rab
print('target max current')
else:
iab = voltage_max / c
vab = iab * Rab
print('target max voltage')
if vab > 25000:
vab = 25000
vab = vab / 1000 * 0.9
elif strategy == 'vmin':
vmn_min = c * current_min
if vmn_min > voltage_min and vmn_min < voltage_max:
vab = current_min * Rab
print('target min current')
else:
iab = voltage_min / c
vab = iab * Rab
print('target min voltage')
if vab < 1000:
vab = 1000
vab = vab / 1000 * 1.1
elif strategy == 'constant':
vab = volt
else:
vab = 5
#self.DPS.write_register(0x09, 0) # DPS5005 off
self.pin0.value = False
self.pin1.value = False
return vab, polarity
def run_measurement(self, quad=[1, 2, 3, 4], nb_stack=None, injection_duration=None,
autogain=True, strategy='constant', tx_volt=5, best_tx_injtime=0.1):
"""Do a 4 electrode measurement and measure transfer resistance obtained.
Parameters
----------
quad : list of int
Quadrupole to measure, just for labelling. Only switch_mux_on/off
really create the route to the electrodes.
nb_stack : int, optional
Number of stacks. A stacl is considered two half-cycles (one
positive, one negative).
injection_duration : int, optional
Injection time in seconds.
autogain : bool, optional
If True, will adapt the gain of the ADS1115 to maximize the
resolution of the reading.
strategy : str, optional
(V3.0 only) If we search for best voltage (tx_volt == 0), we can choose
different strategy:
- vmin: find lowest voltage that gives us a signal
- vmax: find max voltage that are in the range
For a constant value, just set the tx_volt.
tx_volt : float, optional
(V3.0 only) If specified, voltage will be imposed. If 0, we will look
for the best voltage. If a best Tx cannot be found, no
measurement will be taken and values will be NaN.
best_tx_injtime : float, optional
(V3.0 only) Injection time in seconds used for finding the best voltage.
"""
# check arguments
if nb_stack is None:
nb_stack = self.pardict['nb_stack']
if injection_duration is None:
injection_duration = self.pardict['injection_duration']
if tx_volt > 0:
strategy == 'constant'
else:
tx_volt = 5
# inner variable initialization
sum_i = 0
sum_vmn = 0
sum_ps = 0
self.exec_logger.debug('Starting measurement')
self.exec_logger.info('Waiting for data')
# let's define the pin again as if we run through measure()
# as it's run in another thread, it doesn't consider these
# and this can lead to short circuit!
self.pin0 = self.mcp.get_pin(0)
self.pin0.direction = Direction.OUTPUT
self.pin0.value = False
self.pin1 = self.mcp.get_pin(1)
self.pin1.direction = Direction.OUTPUT
self.pin1.value = False
# get best voltage to inject AND polarity
if self.idps:
tx_volt, polarity = self.compute_tx_volt(
best_tx_injtime=best_tx_injtime, strategy=strategy, tx_volt=tx_volt)
print('tx volt V:', tx_volt)
else:
polarity = 1
# first reset the gain to 2/3 before trying to find best gain (mode 0 is continuous)
self.ads_current = ads.ADS1115(self.i2c, gain=2 / 3, data_rate=860, address=0x49, mode=0)
self.ads_voltage = ads.ADS1115(self.i2c, gain=2 / 3, data_rate=860, address=0x48, mode=0)
# turn on the power supply
oor = False
if self.idps:
print('++++ tx_volt', tx_volt)
if np.isnan(tx_volt) == False:
self.DPS.write_register(0x0000, tx_volt, 2) # set tx voltage in V
self.DPS.write_register(0x09, 1) # DPS5005 on
time.sleep(0.05)
else:
print('no best voltage found, will not take measurement')
oor = True
if oor == False:
if autogain:
# compute autogain
self.pin0.value = True
self.pin1.value = False
time.sleep(injection_duration)
gain_current = self.gain_auto(AnalogIn(self.ads_current, ads.P0))
if polarity > 0:
gain_voltage = self.gain_auto(AnalogIn(self.ads_voltage, ads.P0))
else:
gain_voltage = self.gain_auto(AnalogIn(self.ads_voltage, ads.P2))
self.pin0.value = False
self.pin1.value = False
print('gain current: {:.3f}, gain voltage: {:.3f}'.format(gain_current, gain_voltage))
self.ads_current = ads.ADS1115(self.i2c, gain=gain_current, data_rate=860, address=0x49, mode=0)
self.ads_voltage = ads.ADS1115(self.i2c, gain=gain_voltage, data_rate=860, address=0x48, mode=0)
self.pin0.value = False
self.pin1.value = False
# one stack = 2 half-cycles (one positive, one negative)
pinMN = 0 if polarity > 0 else 2
# sampling for each stack at the end of the injection
sampling_interval = 10 # ms
self.nb_samples = int(injection_duration * 1000 // sampling_interval) + 1
# full data for waveform
fulldata = []
# start counter
# we sample every 10 ms (as using AnalogIn for both current
# and voltage takes about 7 ms). When we go over the injection
# duration, we break the loop and truncate the meas arrays
# only the last values in meas will be taken into account
start_time = time.time()
for n in range(0, nb_stack * 2): # for each half-cycles
# current injection
if (n % 2) == 0:
self.pin0.value = True
self.pin1.value = False
else:
self.pin0.value = False
self.pin1.value = True # current injection nr2
print('stack', n, self.pin0.value, self.pin1.value)
# measurement of current i and voltage u during injection
meas = np.zeros((self.nb_samples, 3)) * np.nan
start_delay = time.time() # stating measurement time
dt = 0
for k in range(0, self.nb_samples):
# reading current value on ADS channels
meas[k, 0] = (AnalogIn(self.ads_current, ads.P0).voltage * 1000) / (50 * self.r_shunt)
if pinMN == 0:
meas[k, 1] = AnalogIn(self.ads_voltage, ads.P0).voltage * 1000
else:
meas[k, 1] = AnalogIn(self.ads_voltage, ads.P2).voltage * 1000 *-1
time.sleep(sampling_interval / 1000)
dt = time.time() - start_delay # real injection time (s)
meas[k, 2] = time.time() - start_time
if dt > (injection_duration - 0 * sampling_interval /1000):
break
# stop current injection
self.pin0.value = False
self.pin1.value = False
end_delay = time.time()
# truncate the meas array if we didn't fill the last samples
meas = meas[:k+1]
# measurement of current i and voltage u during off time
measpp = np.zeros((meas.shape[0], 3)) * np.nan
start_delay = time.time() # stating measurement time
dt = 0
for k in range(0, measpp.shape[0]):
# reading current value on ADS channels
measpp[k, 0] = (AnalogIn(self.ads_current, ads.P0).voltage * 1000) / (50 * self.r_shunt)
if pinMN == 0:
measpp[k, 1] = AnalogIn(self.ads_voltage, ads.P0).voltage * 1000
else:
measpp[k, 1] = AnalogIn(self.ads_voltage, ads.P2).voltage * 1000 *-1
time.sleep(sampling_interval / 1000)
dt = time.time() - start_delay # real injection time (s)
measpp[k, 2] = time.time() - start_time
if dt > (injection_duration - 0 * sampling_interval /1000):
break
end_delay = time.time()
# truncate the meas array if we didn't fill the last samples
measpp = measpp[:k+1]
# we alternate on which ADS1115 pin we measure because of sign of voltage
if pinMN == 0:
pinMN = 2
else:
pinMN = 0
# store data for full wave form
fulldata.append(meas)
fulldata.append(measpp)
# wait once the actual injection time between two injection
# so it's a 50% duty cycle
#print('crenaux (s)', (end_delay - start_delay))
#print('sleep for (s)', injection_duration - (end_delay - start_delay))
#print(meas)
#print(measpp)
# TODO get battery voltage and warn if battery is running low
# TODO send a message on SOH stating the battery level
# let's do some calculation (out of the stacking loop)
for n, meas in enumerate(fulldata[::2]):
# take average from the samples per stack, then sum them all
# average for the last third of the stacked values
# is done outside the loop
sum_i = sum_i + (np.mean(meas[-int(meas.shape[0]//3):, 0]))
vmn1 = np.mean(meas[-int(meas.shape[0]//3), 1])
if (n % 2) == 0:
sum_vmn = sum_vmn - vmn1
sum_ps = sum_ps + vmn1
else:
sum_vmn = sum_vmn + vmn1
sum_ps = sum_ps + vmn1
if self.idps:
self.DPS.write_register(0x0000, 0, 2) # reset to 0 volt
self.DPS.write_register(0x09, 0) # DPS5005 off
print('off')
else:
sum_i = np.nan
sum_vmn = np.nan
sum_ps = np.nan
# reshape full data to an array of good size
# we need an array of regular size to save in the csv
if oor == False:
fulldata = np.vstack(fulldata)
# we create a big enough array given nb_samples, number of
# half-cycles (1 stack = 2 half-cycles), and twice as we
# measure decay as well
a = np.zeros((nb_stack * self.nb_samples * 2 * 2, 3)) * np.nan
a[:fulldata.shape[0], :] = fulldata
fulldata = a
else:
np.array([[]])
# create a dictionary and compute averaged values from all stacks
d = {
"time": datetime.now().isoformat(),
"A": quad[0],
"B": quad[1],
"M": quad[2],
"N": quad[3],
"inj time [ms]": (end_delay - start_delay) * 1000 if oor == False else 0,
"Vmn [mV]": sum_vmn / (2 * nb_stack),
"I [mA]": sum_i / (2 * nb_stack),
"R [ohm]": sum_vmn / sum_i,
"Ps [mV]": sum_ps / (2 * nb_stack),
"nbStack": nb_stack,
"Tx [V]": tx_volt if oor == False else 0,
"CPU temp [degC]": CPUTemperature().temperature,
"Nb samples [-]": self.nb_samples,
"fulldata": fulldata,
}
a = deepcopy(d)
a.pop('fulldata')
print(a)
# round number to two decimal for nicer string output
output = [f'{k}\t' for k in d.keys()]
output = str(output)[:-1] + '\n'
for k in d.keys():
if isinstance(d[k], float):
val = np.round(d[k], 2)
else:
val = d[k]
output += f'{val}\t'
output = output[:-1]
self.exec_logger.debug(output)
return d
def rs_check(self, tx_volt=12):
""" Check contact resistance.
"""
# create custom sequence where MN == AB
# we only check the electrodes which are in the sequence (not all might be connected)
elec = np.sort(np.unique(self.sequence.flatten())) # assumed order
quads = np.vstack([
elec[:-1],
elec[1:],
elec[:-1],
elec[1:],
]).T
if self.idps:
quads[:, 2:] = 0 # we don't open Vmn to prevent burning the MN part
# as it has a smaller range of accepted voltage
# create filename to store RS
export_path_rs = self.pardict['export_path'].replace('.csv', '') \
+ '_' + datetime.now().strftime('%Y%m%dT%H%M%S') + '_rs.csv'
# perform RS check
self.run = True
self.status = 'running'
# make sure all mux are off to start with
self.reset_mux()
# measure all quad of the RS sequence
for i in range(0, quads.shape[0]):
quad = quads[i, :] # quadrupole
self.switch_mux_on(quad) # put before raising the pins (otherwise conflict i2c)
d = self.run_measurement(quad=quad, nb_stack=1, injection_duration=1, tx_volt=tx_volt, autogain=False)
if self.idps:
voltage = tx_volt # imposed voltage on dps5005
else:
voltage = d['Vmn [mV]']
current = d['I [mA]']
# compute resistance measured (= contact resistance)
resist = abs(voltage / current) / 1000
print(str(quad) + '> I: {:>10.3f} mA, V: {:>10.3f} mV, R: {:>10.3f} kOhm'.format(
current, voltage, resist))
msg = 'Contact resistance {:s}: {:.3f} kOhm'.format(
str(quad), resist)
self.exec_logger.debug(msg)
# if contact resistance = 0 -> we have a short circuit!!
if resist < 1e-5:
msg = '!!!SHORT CIRCUIT!!! {:s}: {:.3f} kOhm'.format(
str(quad), resist)
self.exec_logger.warning(msg)
print(msg)
# save data and print in a text file
self.append_and_save(export_path_rs, {
'A': quad[0],
'B': quad[1],
'RS [kOhm]': resist,
})
# close mux path and put pin back to GND
self.switch_mux_off(quad)
self.reset_mux()
self.status = 'idle'
self.run = False
#
# # TODO if interrupted, we would need to restore the values
# # TODO or we offer the possiblity in 'run_measurement' to have rs_check each time?
@staticmethod
def append_and_save(filename, last_measurement):
"""Append and save last measurement dataframe.
Parameters
----------
filename : str
filename to save the last measurement dataframe
last_measurement : dict
Last measurement taken in the form of a python dictionary
"""
last_measurement = deepcopy(last_measurement)
if 'fulldata' in last_measurement:
d = last_measurement['fulldata']
n = d.shape[0]
if n > 1:
idic = dict(zip(['i' + str(i) for i in range(n)], d[:,0]))
udic = dict(zip(['u' + str(i) for i in range(n)], d[:,1]))
tdic = dict(zip(['t' + str(i) for i in range(n)], d[:,2]))
last_measurement.update(idic)
last_measurement.update(udic)
last_measurement.update(tdic)
last_measurement.pop('fulldata')
if os.path.isfile(filename):
# Load data file and append data to it
with open(filename, 'a') as f:
w = csv.DictWriter(f, last_measurement.keys())
w.writerow(last_measurement)
# last_measurement.to_csv(f, header=False)
else:
# create data file and add headers
with open(filename, 'a') as f:
w = csv.DictWriter(f, last_measurement.keys())
w.writeheader()
w.writerow(last_measurement)
# last_measurement.to_csv(f, header=True)
def measure(self, **kwargs):
"""Run the sequence in a separate thread. Can be stopped by 'OhmPi.stop()'.
"""
self.run = True
self.status = 'running'
self.exec_logger.debug(f'Status: {self.status}')
def func():
for g in range(0, self.pardict["nbr_meas"]): # for time-lapse monitoring
if self.run is False:
self.exec_logger.warning('Data acquisition interrupted')
break
t0 = time.time()
# create filename with timestamp
filename = self.pardict["export_path"].replace('.csv',
f'_{datetime.now().strftime("%Y%m%dT%H%M%S")}.csv')
self.exec_logger.debug(f'Saving to {filename}')
# make sure all multiplexer are off
self.reset_mux()
# measure all quadrupole of the sequence
for i in range(0, self.sequence.shape[0]):
quad = self.sequence[i, :] # quadrupole
if self.run is False:
break
# call the switch_mux function to switch to the right electrodes
self.switch_mux_on(quad)
# run a measurement
if self.on_pi:
current_measurement = self.run_measurement(quad, **kwargs)
else: # for testing, generate random data
current_measurement = {
'A': [quad[0]], 'B': [quad[1]], 'M': [quad[2]], 'N': [quad[3]],
'R [ohm]': np.abs(np.random.randn(1))
}
# switch mux off
self.switch_mux_off(quad)
# log data to the data logger
self.data_logger.info(f'{current_measurement}')
# save data and print in a text file
self.append_and_save(filename, current_measurement)
self.exec_logger.debug('{:d}/{:d}'.format(i + 1, self.sequence.shape[0]))
# compute time needed to take measurement and subtract it from interval
# between two sequence run (= sequence_delay)
measuring_time = time.time() - t0
sleep_time = self.pardict["sequence_delay"] - measuring_time
if sleep_time < 0:
# it means that the measuring time took longer than the sequence delay
sleep_time = 0
self.exec_logger.warning('The measuring time is longer than the sequence delay. '
'Increase the sequence delay')
# sleeping time between sequence
if self.pardict["nbr_meas"] > 1:
time.sleep(sleep_time) # waiting for next measurement (time-lapse)
self.status = 'idle'
self.thread = threading.Thread(target=func)
self.thread.start()
def stop(self):
"""Stop the acquisition.
"""
self.run = False
if self.thread is not None:
self.thread.join()
self.exec_logger.debug(f'Status: {self.status}')
VERSION = '2.1.0'
print(colored(r' ________________________________' + '\n' +
r'| _ | | | || \/ || ___ \_ _|' + '\n' +
r'| | | | |_| || . . || |_/ / | |' + '\n' +
r'| | | | _ || |\/| || __/ | |' + '\n' +
r'\ \_/ / | | || | | || | _| |_' + '\n' +
r' \___/\_| |_/\_| |_/\_| \___/ ', 'red'))
print('OhmPi start')
print('Version:', VERSION)
platform, on_pi = OhmPi.get_platform()
if on_pi:
print(colored(f'Running on {platform} platform', 'green'))
# TODO: check model for compatible platforms (exclude Raspberry Pi versions that are not supported...)
# and emit a warning otherwise
if not arm64_imports:
print(colored(f'Warning: Required packages are missing.\n'
f'Please run ./env.sh at command prompt to update your virtual environment\n', 'yellow'))
else:
print(colored(f'Not running on the Raspberry Pi platform.\nFor simulation purposes only...', 'yellow'))
current_time = datetime.now()
print(current_time.strftime("%Y-%m-%d %H:%M:%S"))
# for testing
if __name__ == "__main__":
ohmpi = OhmPi(config='ohmpi_param.json')
ohmpi.run_measurement()
#ohmpi.measure()
#ohmpi.read_quad('breadboard.txt')
#ohmpi.measure()
#time.sleep(20)
#ohmpi.stop()