[Nut-upsdev] driver for IVT SCD solar controller ?

Rainer Fuegenstein rfu at kaneda.iguw.tuwien.ac.at
Tue Jul 28 21:23:01 UTC 2009


I'm using the SCD-20 solar controller from IVT Gmbh in combination with a
230Ah battery and a photovoltaic panel to power a small server based on an
Intel ATOM N270 CPU.

the controller is (will be) connected to the server via RS232 (1200 8n1)
and works like this:

- if the battery voltage drops below 12V, a warning LED is switched on
- if the battery voltage drops below 10.5V, the load (the server) is
powered off to prevent exhaustive battery discharge
- if the battery voltage raises above 12V, the power to the server is
switched back on

the info record delivered via RS232 looks like this:

<R: current voltage; current power; current temperature; minimum voltage;
maximum voltage; minimum power; maximum power; CRLF>

from the servers point of view the SCD works similar to an UPS:
- if battery voltage is close to 10.5V, perform shutdown
- if current power < 0, we are running on battery (power consumption is
higher than power generated by the panel)
- if current power > 0, the panel produces more energy than needed and
also charges the battery

- is there already a driver which handles such a device ?
- if not, which driver comes closest to this behaviour ?
- if none, is anybody willing/able to implement such a driver ?

I'm willing to do the implementation, but my c/c++ programming skills are
quite rusty ...

thanks in advance.

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