Rockbox.org home
release
dev builds
extras
themes manual
wiki
device status forums
mailing lists
IRC bugs
patches
dev guide



Rockbox mail archive

Subject: Re: Putting the user in the loop (Was Re: len0x: apps settings.c, 1.310, 1.311)

Re: Putting the user in the loop (Was Re: len0x: apps settings.c, 1.310, 1.311)

From: Jerry Van Baren <gerald.vanbaren_at_smiths-aerospace.com>
Date: 2005-11-04

Neon John wrote:
> On Fri, 04 Nov 2005 15:39:34 +0100, Frederic Devernay
> <frederic.devernay@m4x.org> wrote:
>
>
>>Dear all,
>>
>>I remember having taught human-computer-interaction to masters students for a
>>while (those reading French can take a look at
>><http://devernay.free.fr/cours/IHM/lucid.pdf>), and one of the most important
>>principles you learn is to put the user in the loop when you do interface
>>design. The user has to take part in user interface conception and this usually
>>improves the final result a lot. You also learn that developpers themselves are
>>very bad at improving the UI, simply because they know how it works.
>
>
> Very true. We only need to look at the product of far eastern
> programmed consumer electronics (most of 'em, particularly digital
> cameras) and Windows to see that.

[snip of UI stuff I don't have any words of wisdom to address with]

> * A more aggressive charging algorithm. I'd like to see the batteries
> hit with as much current as possible without getting into thermal
> problems.

Hardware limitation, see below. I don't believe we can make the charge
algorithm any more effective (throwing down the gauntlet ;-).

> It should start charging immediately when shore power is
> attached. That way, one can do "opportunity charging" whenever there
> is a 15 minute or so block of time available.

Part of the charge algorithm change in the April timeframe makes it
start recharging immediately (well, within a second) of plugging in.
Caveat: if the batteries "look like" they are full or nearly full, it
does a "trickle"/"top-off" charge respectively.

http://www.rockbox.org/twiki/bin/view/Main/BatteryFAQ#Q17_My_batteries_are_at_92_the_c

> I'd trade overall battery life (number of cycles) for speed in
> charging. The cost of AA NiMH batteries is trivial these days so if
> they have to be replaced every year, big deal.
>
> I have an Eveready 15 minute charger that hits each battery with >4
> amps. I've seen no detrimental effects to date and I process a LOT of
> batteries through that charger. I'm sure the JBR can't get anywhere
> near that rate but an amp, if that's possible (yeah, with a larger
> wall wart) would be nice.

Sorry, the hardware design doesn't support any more amps. The best it
can do is 350mA (the charger circuitry is "constant current" set to
350mA - you can do less, but you cannot do more). If you put in more
voltage hoping to get more current, it turns into heat inside the AJR
rather than current into the batteries.

http://www.rockbox.org/twiki/bin/view/Main/BatteryFAQ#Q10_Can_I_use_a_different_charge

[snip]

> John
> ---
> John De Armond
> See my website for my current email address
> http://www.johngsbbq.com
> Cleveland, Occupied TN

gvb
Received on Fri Nov 4 21:07:00 2005


Page was last modified "Jan 10 2012" The Rockbox Crew
aaa