Utilizing mostly Adafruit products, this UPS is based on a PowerBoost 1000c controled by an Arduino that emulates the very common Megatec Q protocol over a USB serial connection - For use with NUT "Network UPS Tools" running on Raspberry Pi, Beagle Bone, etc.
This UPS can supply a peak power of slightly more than 1000ma, which is adequate for a headless or external monitor Raspberry Pi 3. It will drive a RP3 with the Foundations 7" touchscreen if processor utilization is low. Power limitations are most evident when running on a low battery. With a low battery, an over-current surge can cause the power converter chip to abruptly shutdown.
These are VERY basic NUT install instructions, please review https://melgrubb.com/2016/12/11/rphs-v2-ups/ for awesome comprehensive instructions from Mel Grubb.
Install NUT:
sudo apt-get install nut
Add user "nut" to "dialout" group to enable access to USB serial port:
sudo usermod -a -G dialout nut
Edit ups.conf:
sudo nano /etc/nut/ups.conf
Add this:
[RPUPS]
driver = blazer_ser
port = /dev/ttyUSB0
desc = “Raspberry Pi UPS"
default.battery.voltage.high = 4.10
default.battery.voltage.low = 3.45
default.battery.voltage.nominal = 3.70
runtimecal = 1500,100,3000,50
#offdelay values in seconds
offdelay = 60
#ondelay values in minutes
ondelay = 1
Edit nut.conf:
sudo nano /etc/nut/nut.conf
Add this:
MODE=standalone
Start NUT:
sudo upsdrvctl start
Edit upsd.users:
sudo nano /etc/nut/upsd.users
Add this (with passwords of your choosing):
[upsmon]
password = raspberry
upsmon master
[admin]
password = raspberry
actions = SET
instcmds = ALL
Edit upsmon.conf:
sudo nano /etc/nut/upsmon.conf
Add to MONITOR section (with your password, not raspberry):
MONITOR RPUPS@localhost 1 upsmon raspberry master
Customize NOTIFYFLAG section (un-comment the messages you want to see):
NOTIFYFLAG
reboot
Querry UPS Status to verify communications:
upsc RPUPS
NUT webpage: http://networkupstools.org
NUT Blazer Serial Driver: http://networkupstools.org/docs/man/blazer_ser.html
Megatec protocol: http://networkupstools.org/protocols/megatec.html
Very nice writeup that I used to install NUT: https://melgrubb.com/2016/12/11/rphs-v2-ups/