[Tuya Smart] Lichuang Tuya version thermometer and hygrometer +955572A

Updated to version V2.0, the single battery design is cancelled, the dual battery is retained, and the supercapacitor is cancelled.

After testing it, the two CR2450s are very easy to use and the standby current is very low. I guess there will be no problem for at least a few months. As for how long it can be used, we will only know when the battery runs out :)

After receiving the components, I simply soldered them, mainly to test whether the single-battery mode is easier to use or the dual-battery mode.

I used two AA batteries to simulate the effect of a single battery, and it was very easy to use. So I followed up and tested a single CR2450+ supercapacitor. It's just ridiculous, the voltage drop is very severe. Single battery mode is abandoned. Just use dual batteries. Ha ha

Also, let me complain, there seems to be a problem with the code of the free development board. It cannot display precise values ​​after the decimal point, only integers such as 12.0 and 13.0. The decimal point must be 0, which is a bit tricky!

This project uses Tuya’s development-free module, which is really simple and practical for someone like me who is illiterate in coding! I was playing with ink screen price tags a while ago and removed a lot of CR2045 batteries, so this circuit uses CR2045 batteries by default. There are two options for the power supply circuit, one is a single battery power supply, and the other is a dual battery power supply in series. Jumper selection is made via shorting solder joints on the back of the motherboard. I'm not sure whether the Tuya module's single battery can work. If the single battery is enough, that would be great. In order to drain the CR2045 battery to the maximum extent, in single battery mode, a supercapacitor is connected in parallel to the 2045 battery. Ensure sufficient power!

The other designs are quite satisfactory. When the time comes, we will directly solder the board for testing!