Merge branch 'develop'

installation_file.txt

+sudo apt-get install python3-venv (déjà installé)
+sudo apt-get install libatlas-base-dev
+mkdir python-virtual-environments
+cd python-virtual-environments
+python3 -m venv ohmpi
+source ohmpi/bin/activate
+pip install RPi.GPIO
+pip install adafruit-blinka
+pip install numpy
+pip install adafruit-circuitpython-ads1x15

ohmpy_v_1_01.py

@@ -6,17 +6,42 @@ OHMPY, it has been developed by Rémi CLEMENT,Vivien DUBOIS, Nicolas FORQUET (IR
 print 'OHMPI start' 
 print MyDateTime.isoformat()
 print 'Import library'
+print('OHMPI start' )
+print('Import library')
 
 #!/usr/bin/python
 import RPi.GPIO as GPIO
 import time
 import datetime
+from datetime import datetime
 import board
 import busio
 import numpy
 import os
+import sys
 import adafruit_ads1x15.ads1115 as ADS
 from adafruit_ads1x15.analog_in import AnalogIn
+import pandas as pd
+import os.path
+
+"""
+display start time
+"""
+current_time = datetime.now()
+print(current_time.strftime("%Y-%m-%d %H:%M:%S"))
+
+"""
+parameters
+"""
+nb_electrodes = 32 # maximum number of electrodes on the resistivity meter
+injection_duration = 0.5 # Current injection duration in second
+nbr_meas= 1 # Number of times the quadripole sequence is repeated
+sequence_delay= 30 # Delay in seconds between 2 sequences
+stack= 1 # repetition of the current injection for each quadripole
+R_ref = 50 # reference resistance value in ohm
+coef_p0 = 2.02 # slope for current conversion for ADS.P0, measurement in ???
+coef_p1 = 2.02 # slope for current conversion for ADS.P1, measurement in ???
+export_path = "/home/pi/Desktop/ohmpy-develop/measurement.csv"
 
 """
 functions
@@ -29,7 +54,106 @@ def switch_mux(quadripole):
         for j in range(0,5) :
             GPIO.output(int(quadmux[i,j]), bool(path2elec[quadripole[i]-1,j]))
 
+# function to find rows with identical values in different columns
+def find_identical_in_line(array_object):
+    output = []
+    if array_object.ndim == 1:
+        temp = numpy.zeros(4)
+        for i in range(len(array_object)):
+            temp[i] = numpy.count_nonzero(array_object == array_object[i])
+        if any(temp > 1):
+            output.append(0)
+    else:
+        for i in range(len(array_object[:,1])):
+            temp = numpy.zeros(len(array_object[1,:]))
+            for j in range(len(array_object[1,:])):
+                temp[j] = numpy.count_nonzero(array_object[i,:] == array_object[i,j])
+            if any(temp > 1):
+                output.append(i)
+    return output
+
+# read quadripole file and apply tests
+def read_quad(filename, nb_elec):
+    output = numpy.loadtxt(filename, delimiter=" ",dtype=int) # load quadripole file
+    # locate lines where the electrode index exceeds the maximum number of electrodes
+    test_index_elec = numpy.array(numpy.where(output > 32))
+    # locate lines where an electrode is referred twice
+    test_same_elec = find_identical_in_line(output)
+    # if statement with exit cases (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,:])):
+            print("Error: An electrode index at line "+ str(test_index_elec[0,i]+1)+" exceeds the maximum number of electrodes")
+        sys.exit(1)
+    elif len(test_same_elec) != 0:
+        for i in range(len(test_same_elec)):
+            print("Error: An electrode index is used twice at line " + str(test_same_elec[i]+1))
+        sys.exit(1)
+    else:
+        return output
+
+# perform a measurement
+def run_measurement(nb_stack, injection_deltat, Rref, coefp0, coefp1):
+    i2c = busio.I2C(board.SCL, board.SDA) # I2C protocol setup
+    ads = ADS.ADS1115(i2c, gain=2/3) # I2C communication setup
+    # inner variable initialization
+    sum_I=0
+    sum_Vmn=0
+    sum_Ps=0
+    # GPIO initialization
+    GPIO.setmode(GPIO.BCM)
+    GPIO.setwarnings(False)
+    GPIO.setup(7, GPIO.OUT)
+    GPIO.setup(8, GPIO.OUT)
+    # resistance measurement
+    for n in range(0,3+2*nb_stack-1) :        
+        if (n % 2) == 0:
+            GPIO.output(7, GPIO.HIGH) # polarité n°1        
+        else:
+            GPIO.output(7, GPIO.LOW) # polarité n°1 également ?        
+        GPIO.output(8, GPIO.HIGH) # current injection
+        time.sleep(injection_deltat) # delay depending on current injection duration
+        Ia1 = AnalogIn(ads,ADS.P0).voltage * coefp0 # reading current value on ADS channel A0
+        Ib1 = AnalogIn(ads,ADS.P1).voltage * coefp1 # reading current value on ADS channel A1
+        Vm1 = AnalogIn(ads,ADS.P2).voltage # reading voltage value on ADS channel A2
+        Vn1 = AnalogIn(ads,ADS.P3).voltage # reading voltage value on ADS channel A3
+        GPIO.output(8, GPIO.LOW)# stop current injection
+        I1= (Ia1 - Ib1)/Rref
+        sum_I=sum_I+I1
+        Vmn1= (Vm1 - Vn1)    
+        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
+    # return averaged values
+    output = pd.DataFrame({
+        "time":[datetime.now()],
+        # rajouter les ABMN
+        "Vmn":[sum_Vmn/(3+2*nb_stack-1)],
+        "I":[sum_I/(3+2*nb_stack-1)],
+        "R":[sum_Vmn/(3+2*nb_stack-1)/(sum_I/(3+2*nb_stack-1))],
+        "Ps":[sum_Ps/(3+2*nb_stack-1)],
+        "nbStack":[nb_stack]
+    })
+    print(output.to_string())
+    return output
+
+# save data
+def append_and_save(path, last_measurement):
+    
+    if os.path.isfile(path):
+        # Load data file and append data to it
+        with open(path, 'a') as f:
+             last_measurement.to_csv(f, header=False)
+    else:
+        # create data file and add headers
+        with open(path, 'a') as f:
+             last_measurement.to_csv(f, header=True)
 
+"""
+Initialization of GPIO channels
+"""                    
 GPIO.setmode(GPIO.BCM)
 GPIO.setwarnings(False)
 
@@ -53,32 +177,26 @@ sequence_delay= 30 # Delay in Second between 2 sequences
 stack= 1 # repetition of the current injection for each quadrupole
 
 """
-Reading the quadripole file
+Main loop
 """
-N=numpy.loadtxt("ABMN.txt", delimiter=" ",dtype=int) # load quadripole file
+N=read_quad("ABMN.txt",nb_electrodes) # load quadripole file
 
 for g in range(0,nbr_meas): # for time-lapse monitoring
 
-    """
-    Selection electrode activées pour chaque quadripole
-    """
-    for i in range(0,N.shape[0]): # boucle sur les quadripôles, qui tient compte du nombre de quadripole dans le fichier ABMN
-        # call switch_mux function
+    for i in range(0,N.shape[0]): # loop over quadripoles
+        # call the switch_mux function to switch to the right electrodes
         switch_mux(N[i,])
 
-        time.sleep(injection_time);
+        # run a measurement
+        current_measurement = run_measurement(stack, injection_duration, R_ref, coef_p0, coef_p1)
+
+        # save data and print in a text file
+        append_and_save(export_path, current_measurement)
+
+        # reset multiplexer channels
         GPIO.output(12, GPIO.HIGH); GPIO.output(16, GPIO.HIGH); GPIO.output(20, GPIO.HIGH); GPIO.output(21, GPIO.HIGH); GPIO.output(26, GPIO.HIGH)
         GPIO.output(18, GPIO.HIGH); GPIO.output(23, GPIO.HIGH); GPIO.output(24, GPIO.HIGH); GPIO.output(25, GPIO.HIGH); GPIO.output(19, GPIO.HIGH)
         GPIO.output(6, GPIO.HIGH); GPIO.output(13, GPIO.HIGH); GPIO.output(4, GPIO.HIGH); GPIO.output(17, GPIO.HIGH); GPIO.output(27, GPIO.HIGH)
         GPIO.output(22, GPIO.HIGH); GPIO.output(10, GPIO.HIGH); GPIO.output(9, GPIO.HIGH); GPIO.output(11, GPIO.HIGH); GPIO.output(5, GPIO.HIGH)
 
-
-    time.sleep(sequence_delay);#waiting next measurement
-
-
-
-
-'''
-Save result in txt file
-'''
-
+    time.sleep(sequence_delay) #waiting next measurement (time-lapse)
\ No newline at end of file