[Nut-upsdev] Best UPS protocol for home-made firmware?

[Charles Lepple]

On Apr 19, 2010, at 4:09 AM, Chris Boot wrote:

> In addition I'm wondering how much NUT looks at various parameters  
> like input / battery / line voltage, since in my case it would be  
> 12-18V and not the more common 110/230V. :-)

In the NUT developer documentation, there are some tables listing the  
variable names:

http://buildbot.networkupstools.org/~buildbot/docs/latest/developer-guide.html#_variables 
  (scroll down to the input and output tables)

For user interfaces, clients should scale their graphs against the  
"input.voltage.nominal" and "output.voltage.nominal" variables. (This  
is what is done in the CGI scripts).

Since you don't want to modify a driver, you probably want to pick a  
protocol which sends back the nominal voltages in an easy-to-parse  
fashion. (For instance, the Tripp Lite protocols encode the line  
voltage as an enumeration, so there would be no easy way to tell it  
that "line voltage" is not 120V or 230V.)

> Once finished I plan to open-source my firmware (written in a mix of  
> C/C++ for the Arduino IDE for AVR microcontrollers) and document my  
> build for all to see.

Sounds cool!