From 31fbeec32a36a86ba434754081c8c963c30a6806 Mon Sep 17 00:00:00 2001
From: Arnaud Watlet <arnaud.watlet@umons.ac.be>
Date: Wed, 22 Feb 2023 15:36:46 +0100
Subject: [PATCH] fixes strategy condition
---
ohmpi.py | 35 ++++++++++++++++++++++++++++-------
1 file changed, 28 insertions(+), 7 deletions(-)
diff --git a/ohmpi.py b/ohmpi.py
index 585bdc35..12afc362 100644
--- a/ohmpi.py
+++ b/ohmpi.py
@@ -315,12 +315,12 @@ class OhmPi(object):
# select a polarity to start with
self.pin0.value = True
self.pin1.value = False
- I=0
- vmn=0
- count=0
# implement different strategy
if strategy == 'vmax':
+ I=0
+ vmn=0
+ count=0
while I < 3 or abs(vmn) < 20 : # I supérieur à 1 mA et Vmn surpérieur
if count >0 :
volt = volt + 2
@@ -377,11 +377,32 @@ class OhmPi(object):
vab = factor * volt * 0.8
if vab > tx_max:
vab = tx_max
-
- elif strategy == 'constant':
- vab = volt
else:
- vab = 5
+ if strategy == 'constant':
+ vab = volt
+ else:
+ vab = 5
+
+ # autogain
+ self.ads_current = ads.ADS1115(self.i2c, gain=2 / 3, data_rate=860, address=self.ads_current_address)
+ self.ads_voltage = ads.ADS1115(self.i2c, gain=2 / 3, data_rate=860, address=self.ads_voltage_address)
+ 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])
+ self.ads_current = ads.ADS1115(self.i2c, gain=gain_current, data_rate=860, address=self.ads_current_address)
+ self.ads_voltage = ads.ADS1115(self.i2c, gain=gain_voltage, data_rate=860, address=self.ads_voltage_address)
+ # 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 # noqa measure current
+ U0 = AnalogIn(self.ads_voltage, ads.P0).voltage * 1000. # noqa measure voltage
+ U2 = AnalogIn(self.ads_voltage, ads.P2).voltage * 1000. # noqa
+
+ # 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
self.DPS.write_register(0x09, 0) # DPS5005 off
# print('polarity', polarity)
--
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