Hi everyone,
This is my first post.
I want to build a custom base plate for either the basic core or the core 2, that is partly similar to the battery bottom 2 or the go/fire battery bottom. I don't need any connectivity, nor do I need the extra battery, the microphone, or the imu.
Requirements and my research
I only need a connection to power. Maybe I throw in a rs485 transciever ic, or connectors for some gpios...
But I have one requirement that is not optional. I need the builtin charging to work and display the correct charging state, but I don't understand if I have to do something special for that. Also I noticed that even when charging via USB-C the charging state does not work when the battery bottom 2 is connected.
I read that you can tell the axp192 chip if the bus connector is sourcing, or sinking power.
I can't use the battery bottom, because they are to high. The whole stack becomes to tall for my application.
Questions
Why is that and can I prevent it?
Why does the battery percentage behave strangely if the internal battery is not connected , but the battery bottom is?
Is the axp192 capable to tell me if the bus is feeding power, so I can tell if the core is placed on the mount?
Does another power base exist?
My project
I want to build room controller and heating control that is mounted on the wall in a light switch box. I am from Germany, where light switch boxes are round and have a diameter of 60 mm and most light switches are about 55mm wide and I want to mount the core 2 or basic core in these.
The mounting itself is not that problematic, since I already printed a prototype cover-plate that fits my light switches. Since I have plenty of room in the electrical box, I am fitting a power-supply and an atom with a bme280 sensor, so the sensor stays in place even if the core is removed and carried around.
I want the core to be removable, so I could take it with me outside or wherever. I didn't decide if I want the cores to be interchangable and if I want that to be possible i need to break out a uart or something, so the atom can tell me where it is placed.