I've finished printing the satellite case. I'm not totaly satisfayed. i think i can do better and smaller and i'd like to add a reed switch for the alarm door. Actually, i'm using ESP01, and there is only 2 GPIO. I'm thinking about using an Wemos D1 or something like this, but i dont know the power consumption of that things and i need to study this before converting the project.
The actual project use a MCP1700 3302e as voltage regulator for stable 3.3v. i'm using plastic insert for screw. they are cheap and easy to use.
Anyway here is the case of the satellite :
Thank you, see you next time , maybe with a new version of this.
You got a pretty cool web interface, and it reconnize some common sensor like BMP280 with i2c bus.
you can set the software to update an MQTT broker (a raspberry pi 3 or 4).
Now the deal is powering the beast. I'm using a unique 18650 battery. I think a 16340 can be used but i dont have any. i printed a case for the battery and soldered an ON/OFF button. i used 28AWG cable, but 22AWG can be good too.
Now the thing is to get 3.3V all the time. A 18650 battery will deliver 4.2V when full charged, wich is too much and 3.4V when discharged. After doing some research i found thant i cant use a standard regulator like an LM2596 cause the voltage dropout will to important.
I buyed an MCP1700 and 2 capacitor (1000uF electrolytic and 0.1uF ceramic). This type of component has a very low dropout voltage. its pretty easy to get this thingh to work. only 3 pins. 1 ground, 1 in, 1 out @3.3v.