PiHut has a guide to using a UBEC with a Raspberry Pi, but it's not the same use case, using a high-end DC power supply instead of a DIY battery pack. MakeUseOf gives the basics, but that's about it.

Rather than search out commercial low-power solutions, [Paul] embraced the hacker spirit and built his own server from five Raspberry Pi 4b single board computers.

The power bank idea was scrapped. [voidon] ... 19 thoughts on “ Convert A Rotary Phone To VOIP Using Raspberry Pi ” Cyk says: March 9, 2015 at 5:01 am ...