How to implement low-pass filter on (voltage, INA219) measured value?
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Laurentp
Jul 22, 2020, 2:49:28 AM7/22/20
to TasmotaUsers
Hi there,
I want to take control of my small (<1kWp @24V) solar power plant and get rid of othere "solar controllers" - non network enabled.
I decided to use ESP-07 (long distance to AP, I use 16dB panel antenna), 3v3 SMPS, and INA219 module.
As Ina withstands only 26V on inputs, I used 1:2 voltage dividers (750ohm + 750om to have divider currenct ~20mA - 1000x INA input current from datasheet) on both sides of the shunt (connected between batteries an"rest of the work on + side, 100A 75mV).
Now INA shows voltage correctly. (half of real).
For now, power inverter is controlled by "other" solar controller, and as batteries have quite high internal impedance, sometimes switches off on "down-spikes" resulting from starting capacitive load not "0 crossing" (LED lamps), where battery capacity is high enough to remain on.
So I'd like to measure and average battery voltage over (example) 60s period. How to do it in Tasmota? (sensors variant). And only the control (this time by myself) power inverter.
1). How to implement this?
2). INA gives crazy current readings (on-module shunt removed) even inputs shorted together, ~16A wit sensor13 set to 10 (1mOhm, closest to real 0.75mOhm shunt resistance). What is possible cause and how to correct this?
I want to take control of my small (<1kWp @24V) solar power plant and get rid of othere "solar controllers" - non network enabled.
I decided to use ESP-07 (long distance to AP, I use 16dB panel antenna), 3v3 SMPS, and INA219 module.
As Ina withstands only 26V on inputs, I used 1:2 voltage dividers (750ohm + 750om to have divider currenct ~20mA - 1000x INA input current from datasheet) on both sides of the shunt (connected between batteries an"rest of the work on + side, 100A 75mV).
Now INA shows voltage correctly. (half of real).
For now, power inverter is controlled by "other" solar controller, and as batteries have quite high internal impedance, sometimes switches off on "down-spikes" resulting from starting capacitive load not "0 crossing" (LED lamps), where battery capacity is high enough to remain on.
So I'd like to measure and average battery voltage over (example) 60s period. How to do it in Tasmota? (sensors variant). And only the control (this time by myself) power inverter.
1). How to implement this?
2). INA gives crazy current readings (on-module shunt removed) even inputs shorted together, ~16A wit sensor13 set to 10 (1mOhm, closest to real 0.75mOhm shunt resistance). What is possible cause and how to correct this?
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