The hardware addresses the node computer, selection of a VOIP phone,
and power supplies for the computer, phone and node radio.
The Raspberry Pi computer was selected because it was small, very
inexpensive, and sufficiently powerful enough to do the job. We are currently
using the model 3B+ with 1 meg of memory.
The Polycom SoundPoint 450 phone was chosen because I had a free supply
of many of these phones as they are now considered obsolete. These phones,
however are rugged and work very well. Most any VOIP phone should
work with this hardware.
The Raspberry requires 5 volts DC. The Phone requires 49 Volts DC for
power-over-ethernet. The Ubiquiti Wi-Fi radios require 24 Volts DC for
power-over-ethernet. We chose to design the system to operate from either
12 volt or 110 volts as these voltages would be the most common available
voltages for emergency power.
A box is built to house the computer and power supplies. The links below
provide details on the construction of this box.
Hardware Pictures
More detail will be added soon.