< !!! NEED TO MODIFY !!! >
A week ago I decided to make an uninterruptible power supply for RPI3. In case when the external power supply fails, Raspberry UPS must provide proper shutdown of RPI3.
As a power source I use two types of batteries - a lithium LSH20 and a lithium polymer battery for which a charge circuit is provided. They can be used together or separately (to choose from). The advantage of the lithium battery is a wide temperature range.
I chose a Atmega328p microcontroller as a control unit and as a result - device is completely Arduino compatible.
Raspberry and Raspberry UPS will be communication through the USB B socket (VCP) and I will try to implement a NUT protocol
Picture below expalins how this UPS have to connect to RPI3:
- Atmega328 microcontroller;
- LSH20 and Li-Po batteries;
- TPS61030 boost converter;
- designed for use in wide temperatue range;
- USB-UART converter;
- operates with standart USB cables;
- battery test circuit;
- fuse protected;
- temperature sensor LM75;
- 2 user leds and 1 button;
- custom enclosure.
Project status :
- Ordering the boards -= PASS =-
- Soldering the device -= PASS =-
- Testing the device -= PASS =-
- Creating the new revision -= work in process... =-