Re: [Server-devel] smooth shutdown for 12V-DC powered XS

2012-05-10 Thread James Cameron
On Thu, May 10, 2012 at 10:20:57AM +0200, K??vin Raymond wrote: It might not be necessary to calibrate, if the raw value is sent to the computer, the computer software can be calibrated instead. It is still be necessary to ensure the values are within the range of the analog to digital

Re: [Server-devel] smooth shutdown for 12V-DC powered XS

2012-05-10 Thread Kévin Raymond
Yes, nice aren't they?  I would not use Arduino where power was critical.  I had assumed that since a server was involved, one more device wouldn't stretch the power budget that far, especially given the benefit that voltage monitoring brings. Oh yes, we will have a fitPC2 and a dreamplug

Re: [Server-devel] smooth shutdown for 12V-DC powered XS

2012-05-09 Thread Kévin Raymond
Keep it simple is probably the best… I've got an Arduino Diecimila, which is quite big for our purpose, I also have a PIC32 Pinguino board, which is really great but too much powerful… Xavier, we could make a really tiny board, or buy one, with a small microcontroller (Microchip is best for USB

Re: [Server-devel] smooth shutdown for 12V-DC powered XS

2012-05-09 Thread James Cameron
On Wed, May 09, 2012 at 11:52:12PM +0200, K??vin Raymond wrote: Keep it simple is probably the best??? I've got an Arduino Diecimila, which is quite big for our purpose, I also have a PIC32 Pinguino board, which is really great but too much powerful??? Xavier, we could make a really tiny

[Server-devel] smooth shutdown for 12V-DC powered XS

2012-05-08 Thread Xavier Carcelle
Dear XS developers, As we plan to install and deploy a fitPC2 as a School Server in our NosyKomba deployment in Madgascar for OLPC France, we plan to powered it with the 12 VDC power-rail (powered by solar panel + battery + regulator). =As we did it with another XS installed but powered by 220VAC

Re: [Server-devel] smooth shutdown for 12V-DC powered XS

2012-05-08 Thread James Cameron
I understand the requirement. There are two approaches. One measures voltage, and when it goes below a threshold begins shutdown, and when it goes below a final threshold it disconnects the load. The second approach is a charge controller, which estimates the capacity of the battery bank by