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pvvx / THB2

Custom firmware for Tuya devices on the PHY622x2 chipset
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battery level calculation #56

Open fcrovy opened 1 week ago

fcrovy commented 1 week ago

Hi, i see in the code that the battery level is 0% with 2 volts and 100% with 3 volts. I have uder test the sensor BTH01 and, if the voltage is under 2.5 volts, the temperature value is in fault (more than 100°C).

In the Tuya developer page indicate that 0% is at 2.5V.

I suggest to change the code in according to Tuya indication.

Fabio

pvvx commented 1 week ago

This is due to the fact that BTH01 contains the cheapest sensor CHT8305. But another sensor may be installed. Datasheet: CHT8305 -> Vcc min 2.5V, max 5 V The CHT8305 is not designed to run on two AAA batteries. For AAA batteries, the discharge standard is up to 0.8 V. https://data.energizer.com/pdfs/e92.pdf https://data.energizer.com/pdfs/l92.pdf https://docs.rs-online.com/3eb6/A700000006538580.pdf ...

Tuya typically sells products that are of poor quality and have inconsistent parts specifications. Tuya is a garbage disposal system from China.

Do not buy thermometers with CHT8305 sensors. There is THB2 for the same price. Operates down to 1.73 V.

pvvx commented 1 week ago

Test BTH01. To test operation on a weak source, a panel was soldered in for the CR20xx battery. Runs on an old CR2025 battery. Then I replaced it with CR2032. There were no changes in the readings at 2.4V. image