Looks neat! How did you do the cutout of the sides of these enclosures?
No magic, this is the work of the CNC...)))
I am hardware engineer, and also I have an experience in programming ATMEL (AVR and CotexM0+) microcontrollers.
I tested this device yesterday and found some issues. Now, I want to share results.
The analog comparator circuit must be modified. AIN0 should left floating (unconnected) and to this pin need connect the internal 1.1V bandgap reference. The 5V_Fail signal must be connected to AIN1 pin.
VD7 must be removed and DC-DC will be works all time except power save mode.
Need to add the MOSFET for manage LiPo charger, because this IC interrupts accumulator detecting signal (this signal always near 4..5 volts).
Need to add the 5V (external) detecting signal to the microcontroller .
Many of the components values should be revised.
All these remarks will be taken into account in the new revision.
Everything else works perfectly!
For the first revision of the device, I'm completely satisfied with the result.
@giltesa I order boards assembly in Ukraine. This is a small company that develops and small-scale production of electronics. The price is very different and depends on many factors, such as quantity and size of components, number of devices, etc. All questions are discussed individually.