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temp: Increase filter time

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Increase the filter constant to 100s to smoothen the signal a lot.  For
online viewing, this is quite nice, but for acquisition, we should
probably look at the raw data...
This commit is contained in:
Rahix 2025-08-24 03:35:41 +02:00
parent 12753d93fb
commit 670576abf8
1 changed files with 7 additions and 3 deletions
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10
Misc/Temp-Monitor/temperature_monitor.py
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@ -19,11 +19,12 @@ THERMISTOR_R25 = 10e3
THERMISTOR_RINF = THERMISTOR_R25 * math.exp(-THERMISTOR_BETA / 298.15) THERMISTOR_RINF = THERMISTOR_R25 * math.exp(-THERMISTOR_BETA / 298.15)
# Filter constant in seconds # Filter constant in seconds
FILTER_RC = 1 FILTER_RC = 100
FILTER_A = 1 / ADC_RATE / (FILTER_RC / 1 / ADC_RATE) FILTER_A = 1 / ADC_RATE / (FILTER_RC / 1 / ADC_RATE)
temperature_filtered = 25 temperature_filtered = -1
last_report = time.ticks_ms() # Ignore the first 5 seconds
last_report = time.ticks_ms() + 5000
while True: while True:
raw_value = cs1237.read() raw_value = cs1237.read()
value = float(raw_value) / (2**24 - 1) value = float(raw_value) / (2**24 - 1)
@ -35,6 +36,9 @@ while True:
temperature = THERMISTOR_BETA / math.log(value / THERMISTOR_RINF) - 273.15 temperature = THERMISTOR_BETA / math.log(value / THERMISTOR_RINF) - 273.15
if temperature_filtered == -1:
temperature_filtered = temperature
temperature_filtered = ( temperature_filtered = (
temperature_filtered * (1 - FILTER_A) + temperature * FILTER_A temperature_filtered * (1 - FILTER_A) + temperature * FILTER_A
) )