Nabble - MicroControllers

Re: Charging SLA Batteries

2009-11-25T19:50:47Z

As far as the diode is concerned, you need to test any given charger to
see if it has been included as part of the design. Some chargers
include it and some don't. Some will have a diode but will have a
resistor divider so they can measure the battery voltage after the
diode. You will need to test.

Put an amp meter in series with the battery and watch what happens when
you unplug the charger. It may begin to drain the battery or it may
not... if it doesn't then you don't have to worry about it.

Charge time depends on how deep you let the battery discharge. You are
correct with your math(s)! Let us know how you work things out...

Josh Koffman wrote:

> On Wed, Nov 25, 2009 at 1:50 PM, M.L. <m@...> wrote:
>> It depends on how "smart" the chargers are. If they have any smarts
>> at all, they will cut out at a voltage somewhere close to 14 volts.
>> So no, your batteries will never get fully charged if you put a
>> diode in series with the charger.
>
> Ok, no diode. I'll work something out with a switch for this
> prototype and we'll see what happens in the final.
>
> These chargers seem somewhat smart, so they'll switch from fast
> charge to float when the battery is nearing capacity. If that's the
> case, how can I estimate charging time? My pack will be 7AH. Given a
> charger of 750mA should it take roughly 10 hours to charge? If I went
> with the 1.25A model would it then take about 5.5 hours?
>
> Thanks!
>
> Josh

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Re: Charging SLA Batteries

2009-11-25T19:33:42Z

On Wed, Nov 25, 2009 at 1:50 PM, M.L. <m@...> wrote:
> It depends on how "smart" the chargers are. If they have any smarts at
> all, they will cut out at a voltage somewhere close to 14 volts. So
> no, your batteries will never get fully charged if you put a diode in
> series with the charger.

Ok, no diode. I'll work something out with a switch for this prototype
and we'll see what happens in the final.

These chargers seem somewhat smart, so they'll switch from fast charge
to float when the battery is nearing capacity. If that's the case, how
can I estimate charging time? My pack will be 7AH. Given a charger of
750mA should it take roughly 10 hours to charge? If I went with the
1.25A model would it then take about 5.5 hours?

Thanks!

Josh
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Re: How do modern camera flashes work?

2009-11-25T17:27:18Z

I wrote :

> I think inductors/chokes come into it somewhere too. Not as the
> primary switch (if I can invent such a term) but to limit current

Poorly written. What I meant was that for a full flash the capacitor is
allowed to discharge directly into the tube, but a lesser flash may use
a choke to either impede current or as component to measure current
through and stop the discharge
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Re: Ink jet cartridges not used for a while

2009-11-25T17:26:02Z

On Wed, Nov 25, 2009 at 10:12 PM, Tamas Rudnai <tamas.rudnai@...> wrote:
> Hi,
>
> I have a Dell AIO 950 and I did not use that printer for a year.
> Yesterday I wanted to print something and realised that the black ink
> does not work. I think it could have been dried out? Is there any way
> to get it back, or should not bother just buy a new cartridge? (but
> then I won't use that again for a year so dunno what to do with an
> inkjet if that happens every often...) Any advise?
>

Buy a new cartridge. Or better give up using the Inkjet. Laser
printer are getting cheaper now and they are easier to
maintain and more economic to use in the long run.
The main printer we use now is a 2.5 years old Samsung SCX-4200
(mono MFP). And my photo printer (Samsung SPP-2020, around 3
year old) is not an inkjet, it is using Dye Diffusion Thermal Transfer
and it works well. The old Canon Inkjet is still alive but we seldom
use it.

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Re: How do modern camera flashes work?

2009-11-25T15:37:56Z

> Wow, that is an impressive page. Nice work!

Thank you very much

It's still under construction. Unfortunately I've got bogged down
in a couple of favours that have turned into time-eating monsters
or I'd be playing around with breaking things/blowing stuff up for
more pictures and making the PCBs and s/w presentable. And
now I've found out my neighbour has an airgun and a 22 and
there's a new series of Timewarp started ........

I haven't included descriptions or s/w for the PICs yet, but briefly
the 18F1320 is a timer with settable delay from trigger, repeat
delay and number of flashes (hence the tactswitches). The 16F628
triggers the flashes, from 1 at a time to 10 at a time (bright !), the
16F88 is a delay timer from the shutter via the hot shoe. I wanted
this to separate the camera's internal front or rear curtain flash from
external flashes to give for example flash, movement, flash, movement,
flash, which gives a picture some dynamics

New 22uF are used, although disposables have 80 - 160uF. I did
it my way to get the repeat rate up, but I'm considering FETs to
switch in the disposable caps for extra power. I think it's simpler
and more versatile to make a number of smaller flash units that can
be fired individually or in unison rather than attempt one large unit.
It would also be possible to put different-coloured filters in front
of each tube for example. I've lots of other notes and points which
will be on the page eventually once I've stopped doing people
favours ;-)

wbr
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Re: Limits of virtualization (VMware etc)

2009-11-25T14:58:14Z

Answering myself:

After about 6 months of successful work on PICKIT2/ICD2/PIC32 starter kit
among many other USB devices (including mass storage and USB/RS232 chips) I
found VMWare Server 2.x working really well, mostly for being a free
download. Fully recommended for those of you looking for working on isolated
VM inside a host you want to keep clean, for reference a WinVista 64bits
hosts nicely multiple WinXP 32bits sessions with USB hardware so far for me.

VMWare USB driver layer works so well for me that in some cases is better
than working on the host, for instace there are some cheap chips like HL340
for USB/RS232 which don't like WinVista 64bits, but the driver VMWare puts
on the 64bits host to proxy it on the guest ignores this fact and HL340
installs just nicely on the guest even though it wouldn't work on the host.

Another neat feature is the fact you can work remotely with VMWare console
from a laptop, and connect/disconnect the USB device with a drop down list
remotely as well, making the guest software really emulate plug-in/out USB
so you don't have to physically be there to reinit the driver or simulate
faulty connection.

Cheers.

2009/3/2 Ariel Rocholl <arocholl@...>

> Just reviving this old thread, wondering if newest VMWare under Windows
> works well in your experience guys with ICD2 and/or PICKIT2 and/or PIC32
> Starter Kit. We may need to plan for new hardware soon and being VMWare a
> reliable platform in terms of USB would certainly influence our approach on
> how we deploy it.
>
> Any experience with recent VMWare versions in this regards is really
> appreciated (again context is WindowsXP-guest on WindowsXP-host, I saw the
> Fusion thread but looks like different context than mine)
>
> TIA
>
> 2007/12/5 Herbert Graf <mailinglist3@...>
>
> On Tue, 2007-12-04 at 21:24 -0600, Matt Pobursky wrote:
>> > Most of my bad experiences with VMWare were hardware related, i.e. the
>> CCS
>> > USB ICD PIC programmer/debugger software failed to find and control the
>> ICD
>> > pod, similar problems with the programming software and IDE Debugger for
>> > both the USB and parallel port JTAG pods for the MSP430 family. These
>> were
>> > the last devices I tried about a year ago.
>>
>> FWIW the MChip ICD2 works wonderfully under VMWare.
>>
>> TTYL
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>>
>
>
>
> --
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> Madrid, Spain
>

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Re: Best laser printer for PCB designs?

2009-11-25T14:53:11Z

I've had success with Samsung ML1710 using glossy magazine pages.

2009/11/25 Peter Bindels <dascandy@...>:
> I've used my ML-1610 (it's a bit old, but identical otherwise) and

>
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Re: How do modern camera flashes work?

2009-11-25T14:49:29Z

Wow, that is an impressive page. Nice work!

David

Quoting Jinx <joecolquitt@...>:

> > The flash in my Canon Elph is probably a fairly typical example of a
> > modern flash. It flashes twice in quick succession, the first time is
> > for exposure and maybe focus. The second time it's for taking the
> > picture.
>
> The Canon I have will do several flashes in very quick succession for
> focussing etc. I'm guessing it's at most 1/20th between them
>
> > In old-fashioned flashes, the flash had an inverter charging a big
> > capacitor that had a Xenon flash tube across it, and a little SCR
> > that hit a second, smaller transformer to trigger the flash tube. The
> > big capacitor is drained pretty heavily and takes time to recharge,
> > it can't flash twice in a tenth of a second.
>
> I believe it's current control using semis. The same way that extremely
> short flashes of a known length are made for high speed photography
>
> What I think happens is - when the tube is triggered the xenon
> becomes pretty much a dead short across the reservoir cap and the
> discharge current is hundreds of A / cm^2 until the lower conduction
> threshold voltage is reached, at which time the flash stops. To make
> the flash shorter, you need to prematurely pinch off the energy supply
> to the tube before it's exhausted the reservoir cap (if there's only one)
>
> I've been playing around with external flashes. Not difficult to build
> and control with a PIC
>
> http://home.clear.net.nz/pages/joecolquitt/multi-flash.html
>
> Despite cheap digital cameras, an extraordinary number of used
> disposables are available free from processors
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Re: Sparkfun Free Day

2009-11-25T14:37:49Z

On Wed, 2009-11-25 at 14:06 -0800, Bob Blick wrote:

> Sparkfun Electronics is having a "free for the cost of shipping" day Jan
> 7:
>
> http://www.sparkfun.com/commerce/news.php?id=305
>
> I say it'll be a "test out the new server" day too :)
>
> Have at them!
>
> Cheers,
>
> Bob

Dammit Bob, why'd you have to tell us so early!? :) That's awesome
though, what gave you the idea?

TTYL

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Re: How do modern camera flashes work?

2009-11-25T14:36:49Z

>> I think they use IGBTs to control the flash current (interrupt it
>> before the photoflash cap is discharged too much). IGBTs are
>> generally a more appropriate choice than MOSFETs in this kind
>> of application.

I think inductors/chokes come into it somewhere too. Not as the
primary switch (if I can invent such a term) but to limit current
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Re: How do modern camera flashes work?

2009-11-25T14:34:20Z

> The flash in my Canon Elph is probably a fairly typical example of a
> modern flash. It flashes twice in quick succession, the first time is
> for exposure and maybe focus. The second time it's for taking the
> picture.

The Canon I have will do several flashes in very quick succession for
focussing etc. I'm guessing it's at most 1/20th between them

> In old-fashioned flashes, the flash had an inverter charging a big
> capacitor that had a Xenon flash tube across it, and a little SCR
> that hit a second, smaller transformer to trigger the flash tube. The
> big capacitor is drained pretty heavily and takes time to recharge,
> it can't flash twice in a tenth of a second.

I believe it's current control using semis. The same way that extremely
short flashes of a known length are made for high speed photography

What I think happens is - when the tube is triggered the xenon
becomes pretty much a dead short across the reservoir cap and the
discharge current is hundreds of A / cm^2 until the lower conduction
threshold voltage is reached, at which time the flash stops. To make
the flash shorter, you need to prematurely pinch off the energy supply
to the tube before it's exhausted the reservoir cap (if there's only one)

I've been playing around with external flashes. Not difficult to build
and control with a PIC

http://home.clear.net.nz/pages/joecolquitt/multi-flash.html

Despite cheap digital cameras, an extraordinary number of used
disposables are available free from processors
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Sparkfun Free Day

2009-11-25T14:06:27Z

Sparkfun Electronics is having a "free for the cost of shipping" day Jan
7:

http://www.sparkfun.com/commerce/news.php?id=305

I say it'll be a "test out the new server" day too :)

Have at them!

Cheers,

Bob

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Re: How do modern camera flashes work?

2009-11-25T13:59:01Z

On Wed, 25 Nov 2009 16:47:26 -0500, "Spehro Pefhany" said:

>
> I think they use IGBTs to control the flash current (interrupt it before
> the
> photoflash cap is discharged too much). IGBTs are generally a more
> appropriate
> choice than MOSFETs in this kind of application.

That makes sense, then they could do all sorts of clever things, flash
several times for effects, etc.

It would take some interesting calculating of the on-time as the cap
voltage would be lower each flash. A monitoring photodiode might be an
easy cheat for that.

Thanks!

Cheers,

Bob

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Re: How do modern camera flashes work?

2009-11-25T13:49:29Z

On Wed, 2009-11-25 at 13:28 -0800, Bob Blick wrote:

> On Wed, 25 Nov 2009 15:58:10 -0500, "Herbert Graf" <hkgraf@...>
> said:
>
> >
> > You know, that's a really good question... perhaps they have two "big
> > caps" and a switch that switches to the second cap after the first
> > flash?
>
> That's what I was thinking. I could reuse the trigger and charge
> circuitry(plus a rectifier for each cap), and use the flip-flop to
> alternate the two caps.
>
> I wonder how much current I need to plan for? It would be nice to use
> MOSFETs for the switches so I'm not burning up base drive on a
> bipolar/darlington, but 400V devices have pretty high Rds. I guess I'll
> have to try to measure the peak current (without getting shocked too
> many times). Thanks!

You could calculate. Check the rating on the cap in question, find the
typical flash duration and minimum voltage the flash will sustain the
arc and a little math should give you an idea.

TTYL

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Re: Ink jet cartridges not used for a while

2009-11-25T13:48:12Z

Yeah ... some wives dont have a sense of humour.

Mine was the same too Peter, when I tried that with my HP cartridges :)

Regards, Roger

----- Original Message -----
From: "Peter van Hoof" <pvhoof@...>
To: "Microcontroller discussion list - Public." <piclist@...>
Sent: Thursday, November 26, 2009 7:22 AM
Subject: Re: [OT] Ink jet cartridges not used for a while

> Though it is stupid (according to my wife).
> I apply suction with my mouth (might get you a black tongue or lips
> tough).
> plain water helps with HP cartridges.
>
> Peter van Hoof
>
>
> ----- Original Message ----

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From forum: PIC - [OT]

Re: How do modern camera flashes work?

2009-11-25T13:47:26Z

At 03:37 PM 25/11/2009, you wrote:

>The flash in my Canon Elph is probably a fairly typical example of a
>modern flash. It flashes twice in quick succession, the first time is
>for exposure and maybe focus. The second time it's for taking the
>picture.
>
>In old-fashioned flashes, the flash had an inverter charging a big
>capacitor that had a Xenon flash tube across it, and a little SCR that
>hit a second, smaller transformer to trigger the flash tube. The big
>capacitor is drained pretty heavily and takes time to recharge, it can't
>flash twice in a tenth of a second.
>
>Any idea how they get two quick flashes in my camera? I'd love to be
>able to use my cheap slave flash to augment the one in the camera, but I
>don't see how any of the circuitry can be reused. And I already tried
>putting a flip-flop in, so that it would only fire the second time. My
>test pictures were overexposed because the first flash(the one that sets
>the exposure) wasn't augmented by the slave flash.
>
>Thanks,
>
>Bob

I think they use IGBTs to control the flash current (interrupt it before the
photoflash cap is discharged too much). IGBTs are generally a more appropriate
choice than MOSFETs in this kind of application.

>Best regards,

Spehro Pefhany --"it's the network..." "The Journey is the reward"
speff@... Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

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Re: How do modern camera flashes work?

2009-11-25T13:36:12Z

Bob Blick wrote:
> I wonder how much current I need to plan for? It would be nice to use
> MOSFETs for the switches so I'm not burning up base drive on a
> bipolar/darlington, but 400V devices have pretty high Rds. I guess I'll
> have to try to measure the peak current (without getting shocked too
> many times). Thanks!
>

How many times is too many anyway Bob? :-D
David...

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Re: How do modern camera flashes work?

2009-11-25T13:28:26Z

On Wed, 25 Nov 2009 15:58:10 -0500, "Herbert Graf" <hkgraf@...>
said:

>
> You know, that's a really good question... perhaps they have two "big
> caps" and a switch that switches to the second cap after the first
> flash?

That's what I was thinking. I could reuse the trigger and charge
circuitry(plus a rectifier for each cap), and use the flip-flop to
alternate the two caps.

I wonder how much current I need to plan for? It would be nice to use
MOSFETs for the switches so I'm not burning up base drive on a
bipolar/darlington, but 400V devices have pretty high Rds. I guess I'll
have to try to measure the peak current (without getting shocked too
many times). Thanks!

Cheerful regards,

Bob

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RE: Ink jet cartridges not used for a while

2009-11-25T13:27:22Z

I find standing the carts on a cloth or thick tissue that is dampened
with the solvent of your choice works well, the capillary action draws
out ink to prime things a bit.
Bonus: you get a crude chromatographic analysis of the pigments too :)

Cheers,
Robin.
-----Original Message-----
From: piclist-bounces@... [mailto:piclist-bounces@...] On Behalf
Of Peter van Hoof
Sent: 25 November 2009 20:52
To: Microcontroller discussion list - Public.
Subject: Re: [OT] Ink jet cartridges not used for a while

Though it is stupid (according to my wife).
I apply suction with my mouth (might get you a black tongue or lips
tough).
plain water helps with HP cartridges.

Peter van Hoof

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From forum: PIC - [OT]

Re: How do modern camera flashes work?

2009-11-25T13:09:41Z

Just a thought - if the slave is cheap enough, you've already done the hard work with the flip flop. It may be cheapest to use 2 flashes of the same type in the same position and trigger one on the pre-flash and the second as you do now.

-Skip

------Original Message------
From: Bob Blick
Sender: piclist-bounces@...
To: piclist@...
ReplyTo: Microcontroller discussion list - Public.
Subject: [EE] How do modern camera flashes work?
Sent: Nov 25, 2009 3:37 PM

The flash in my Canon Elph is probably a fairly typical example of a
modern flash. It flashes twice in quick succession, the first time is
for exposure and maybe focus. The second time it's for taking the
picture.

In old-fashioned flashes, the flash had an inverter charging a big
capacitor that had a Xenon flash tube across it, and a little SCR that
hit a second, smaller transformer to trigger the flash tube. The big
capacitor is drained pretty heavily and takes time to recharge, it can't
flash twice in a tenth of a second.

Any idea how they get two quick flashes in my camera? I'd love to be
able to use my cheap slave flash to augment the one in the camera, but I
don't see how any of the circuitry can be reused. And I already tried
putting a flip-flop in, so that it would only fire the second time. My
test pictures were overexposed because the first flash(the one that sets
the exposure) wasn't augmented by the slave flash.

Thanks,

Bob

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*Sent from my BlackBerry Storm*

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Re: How do modern camera flashes work?

2009-11-25T13:01:42Z

I thought that the first flash was for red eye reduction.

On Wed, Nov 25, 2009 at 3:37 PM, Bob Blick <bobblick@...> wrote:

> The flash in my Canon Elph is probably a fairly typical example of a
> modern flash. It flashes twice in quick succession, the first time is
> for exposure and maybe focus. The second time it's for taking the
> picture.
>
> In old-fashioned flashes, the flash had an inverter charging a big
> capacitor that had a Xenon flash tube across it, and a little SCR that
> hit a second, smaller transformer to trigger the flash tube. The big
> capacitor is drained pretty heavily and takes time to recharge, it can't
> flash twice in a tenth of a second.
>
> Any idea how they get two quick flashes in my camera? I'd love to be
> able to use my cheap slave flash to augment the one in the camera, but I
> don't see how any of the circuitry can be reused. And I already tried
> putting a flip-flop in, so that it would only fire the second time. My
> test pictures were overexposed because the first flash(the one that sets
> the exposure) wasn't augmented by the slave flash.
>
> Thanks,
>
> Bob
>
> --
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> wherever you are
>
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Re: How do modern camera flashes work?

2009-11-25T12:58:10Z

On Wed, 2009-11-25 at 12:37 -0800, Bob Blick wrote:

> The flash in my Canon Elph is probably a fairly typical example of a
> modern flash. It flashes twice in quick succession, the first time is
> for exposure and maybe focus. The second time it's for taking the
> picture.
>
> In old-fashioned flashes, the flash had an inverter charging a big
> capacitor that had a Xenon flash tube across it, and a little SCR that
> hit a second, smaller transformer to trigger the flash tube. The big
> capacitor is drained pretty heavily and takes time to recharge, it can't
> flash twice in a tenth of a second.

You know, that's a really good question... perhaps they have two "big
caps" and a switch that switches to the second cap after the first
flash?

> Any idea how they get two quick flashes in my camera? I'd love to be
> able to use my cheap slave flash to augment the one in the camera, but I
> don't see how any of the circuitry can be reused. And I already tried
> putting a flip-flop in, so that it would only fire the second time. My
> test pictures were overexposed because the first flash(the one that sets
> the exposure) wasn't augmented by the slave flash.

You could use 2 slave flashes? One that flashes with the first, and your
other one with the flop flashing with the second?

Thanks, TTYL

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Re: Ink jet cartridges not used for a while

2009-11-25T12:52:24Z

Though it is stupid (according to my wife).
I apply suction with my mouth (might get you a black tongue or lips tough).
plain water helps with HP cartridges.

Peter van Hoof

----- Original Message ----

> From: Tamas Rudnai <tamas.rudnai@...>
> To: Microcontroller discussion list - Public. <piclist@...>
> Sent: Wed, November 25, 2009 11:25:33 AM
> Subject: Re: [OT] Ink jet cartridges not used for a while
>
> Thanks guys, will give is a go. Tried iso-propil yesterday but that
> did not work, will try with alcohol and water as also suggested.
>
> Thanks,
> Tamas
>
>
>
>
> On Wed, Nov 25, 2009 at 4:12 PM, Dario Greggio wrote:
> > John Chung ha scritto:
> >> Use alcohol. I use it for my fountain pens. Just suspend the cartridge in mid
> air into the solution*the nozzle head*. A few minutes should dilute the dried
> ink.
> >
> >
> > same here. works !
> >
> > Dario
> > --
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> > View/change your membership options at
> > http://mailman.mit.edu/mailman/listinfo/piclist
> >
>
>
>
> --
> /* www.mcuhobby.com */ int main() { char *a,*s,*q; printf(s="/*
> www.mcuhobby.com */ int main() { char *a,*s,*q; printf(s=%s%s%s,
> q=%s%s%s%s,s,q,q,a=%s%s%s%s,q,q,q,a,a,q); }",
> q="\"",s,q,q,a="\\",q,q,q,a,a,q); }
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From forum: PIC - [OT]

How do modern camera flashes work?

2009-11-25T12:37:47Z

The flash in my Canon Elph is probably a fairly typical example of a
modern flash. It flashes twice in quick succession, the first time is
for exposure and maybe focus. The second time it's for taking the
picture.

In old-fashioned flashes, the flash had an inverter charging a big
capacitor that had a Xenon flash tube across it, and a little SCR that
hit a second, smaller transformer to trigger the flash tube. The big
capacitor is drained pretty heavily and takes time to recharge, it can't
flash twice in a tenth of a second.

Any idea how they get two quick flashes in my camera? I'd love to be
able to use my cheap slave flash to augment the one in the camera, but I
don't see how any of the circuitry can be reused. And I already tried
putting a flip-flop in, so that it would only fire the second time. My
test pictures were overexposed because the first flash(the one that sets
the exposure) wasn't augmented by the slave flash.

Thanks,

Bob

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Re: Ink jet cartridges not used for a while

2009-11-25T11:34:49Z

The favorite solution of choice for Epson inkjet owners is a window
cleaning product that contains ammonia such as Windex brand in the US.

With Epsons, the print head is part of the printer, not part of the ink
cartridge. So when Epsons get a clog, you either fix it or get a new
printer.

Inkjet printers are not the best choice for printing only once per year;
if you do this, think about running a test print once a month at least
to keep the heads open. Also, most printers need to be powered off by
the power switch which causes them to move the print head onto either a
pad or on some, they actually close a "door" over the nozzles. Simply
removing power (yanking the plug, etc.) won't perform this and the heads
then may dry out creating a clog.

Brendan Gillatt wrote:
>
> Had exactly the same problem as you (Canon MP610). I tried alcohol,
> detergent and soap and none worked. What _did_ work, however, was very
> hot water. I got a bowl full straight from the hot tap and soaked the
> print head for 15 minutes or so with the nozzle just under the surface.
> Repeat that a couple of times so the water doesn't get too cool and it
> worked first time.

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From forum: PIC - [OT]

Re: Ink jet cartridges not used for a while

2009-11-25T11:32:18Z

> > I have a Dell AIO 950 and I did not use that printer for a year.
> > Yesterday I wanted to print something and realised that the black ink
> > does not work. I think it could have been dried out? Is there any way
> > to get it back, or should not bother just buy a new cartridge? (but
> > then I won't use that again for a year so dunno what to do with an
> > inkjet if that happens every often...) Any advise?

Ether-based glass cleaner "Invisible Glass" is what I have used.

Cheers,

Bob

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From forum: PIC - [OT]

Re: Charging SLA Batteries

2009-11-25T11:16:01Z

Josh Koffman escreveu:

> On Wed, Nov 25, 2009 at 12:01 PM, Bob Blick <bobblick@...> wrote:
>
>>> 2. If I understand this correctly, I should be charging these guys at
>>> somewhere between 700mA to 2A. Is that correct?
>>>
>> Sounds reasonable.
>>
>>
>>> 3. If 24V charging is ok, what about this charger:
>>> http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=102-1956-ND
>>> or would I want to go with something with a higher current like this:
>>> http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=271-2391-ND
>>>
>> Surprisingly nice looking chargers!
>>
>> New 7 AH batteries are quite tough and I would have no problem with
>> either of those chargers since they look intelligent.
>>
>
> It's the top hat and tux, everyone looks intelligent in that get-up!
>
> Seriously though, I'm glad these ones look ok. I suppose the
> difference between the two would be in how long the battery takes to
> charge, correct?
>
> Also what would happen if I inserted a diode in between the charger
> and the battery packs. This way I could have a relay disconnect the
> operating circuit when the charger is inserted. Would this mess up my
> charging by dropping the voltage though?
>
> Thanks!
>
> Josh
>

I don't know how those chargers work, but if they depend on being able
to measure the battery voltage while the charging is stopped, then it
won't work at all.

I once developed a charger for a product that has an internal battery
with a diode to prevent reverse charging. I needed to use a PIC that
first applied a little current to be able to measure the battery voltage
indirectly and then switched to the charging cycle.

If the charger needs to measure the battery voltage before starting the
charge, I would expect it to oscillate when connected to a charged battery.

Best regards,

Isaac

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Re: Ink jet cartridges not used for a while

2009-11-25T11:10:41Z

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Tamas Rudnai wrote:

> Hi,
>
> I have a Dell AIO 950 and I did not use that printer for a year.
> Yesterday I wanted to print something and realised that the black ink
> does not work. I think it could have been dried out? Is there any way
> to get it back, or should not bother just buy a new cartridge? (but
> then I won't use that again for a year so dunno what to do with an
> inkjet if that happens every often...) Any advise?
>
> Thanks
> Tamas

Had exactly the same problem as you (Canon MP610). I tried alcohol,
detergent and soap and none worked. What _did_ work, however, was very
hot water. I got a bowl full straight from the hot tap and soaked the
print head for 15 minutes or so with the nozzle just under the surface.
Repeat that a couple of times so the water doesn't get too cool and it
worked first time.

- --
Brendan Gillatt | GPG Key: 0xBF6A0D94
brendan {a} brendangillatt (dot) co (dot) uk
http://www.brendangillatt.co.uk
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Version: GnuPG v1.4.7 (MingW32)

iD8DBQFLDYExHEhZ5Ws5poERAiG5AJoD7BHcXmL4oROYK9xenCk4er6ukwCeIATZ
ApASuBltdRgLc04dSrrWHjM=
=nqTC
-----END PGP SIGNATURE-----
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From forum: PIC - [OT]

Re: accessing bits in a structure like an array

2009-11-25T11:09:55Z

On Wed, Nov 25, 2009 at 12:39 PM, Gerhard Fiedler
<lists@...> wrote:

> Mark Rages wrote:
>
>> and instead of an enum I would define a bitmask
>>
>> #define SUN (1<<0)
>> #define MON (1<<1)
>
> Do you see an advantage to use #defines instead of an enum?
>
> typedef enum _WEEK_DAYS
> {
> SUN = (1<<0),
> MON = (1<<1),
> ...
> } WEEK_DAYS;
>
> In the end not much of a difference, but an enum has the advantage of
> not being textual replacement.
>

It must be a style thing, but I never use enums for bit masks.

Regards,
Mark
markrages@gmail
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From forum: PIC - [PIC]

Submit some patches

2009-11-25T11:02:38Z

hi everyone,

my first post here...
I have inherited a firmware project that was based on ethernut 4.0.1.
This project contains a number of modifications to the Nut/OS, which I
dont know if they were ever submitted as patches or not. I have merged
the patches with 4.8.5 and tested them. They work well, so I have
submitted them to sourceforge in the patch area. Please evaluate the
utility and applicability of them.

They are:

1. fix to nut\crt\write.c to guarantee serialized access to the
write used in fputs.c. this prevents multiple threads from interleaving
characters
2. fix to \nut\pro\dhcpc.c - modification to DHCP client code so
you can switch between DHCP and static IP addresses without
resetting/power cycling.
3. fix to nut\net\ifconfig.c - modification so NutNetIfSetup()
doesn't save settings to the EEPROM. This was using up the available
memory writes for the eeprom part since it happens each time the unit
powers up. Code was added to the application to determine when the
network information should be saved in the EEPROM. This might impact
compatibility, so maybe this needs to be implemented as a parameter to
this function.

thanks

Rich

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From forum: MicroControllers - Ethernut

Re: Charging SLA Batteries

2009-11-25T10:50:29Z

On Wed, Nov 25, 2009 at 1:42 PM, Josh Koffman <joshybear@...> wrote:

> Also what would happen if I inserted a diode in between the charger
> and the battery packs. This way I could have a relay disconnect the
> operating circuit when the charger is inserted. Would this mess up my
> charging by dropping the voltage though?
>
> Thanks!
>
> Josh

It depends on how "smart" the chargers are. If they have any smarts at
all, they will cut out at a voltage somewhere close to 14 volts. So
no, your batteries will never get fully charged if you put a diode in
series with the charger.

--
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From forum: PIC - [EE]

Re: Charging SLA Batteries

2009-11-25T10:42:22Z

On Wed, Nov 25, 2009 at 12:01 PM, Bob Blick <bobblick@...> wrote:

>> 2. If I understand this correctly, I should be charging these guys at
>> somewhere between 700mA to 2A. Is that correct?
> Sounds reasonable.
>
>> 3. If 24V charging is ok, what about this charger:
>> http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=102-1956-ND
>> or would I want to go with something with a higher current like this:
>> http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=271-2391-ND
>
> Surprisingly nice looking chargers!
>
> New 7 AH batteries are quite tough and I would have no problem with
> either of those chargers since they look intelligent.

It's the top hat and tux, everyone looks intelligent in that get-up!

Seriously though, I'm glad these ones look ok. I suppose the
difference between the two would be in how long the battery takes to
charge, correct?

Also what would happen if I inserted a diode in between the charger
and the battery packs. This way I could have a relay disconnect the
operating circuit when the charger is inserted. Would this mess up my
charging by dropping the voltage though?

Thanks!

Josh
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From forum: PIC - [EE]

Re: accessing bits in a structure like an array

2009-11-25T10:39:42Z

Mark Rages wrote:

> and instead of an enum I would define a bitmask
>
> #define SUN (1<<0)
> #define MON (1<<1)

Do you see an advantage to use #defines instead of an enum?

typedef enum _WEEK_DAYS
{
SUN = (1<<0),
MON = (1<<1),
...
} WEEK_DAYS;

In the end not much of a difference, but an enum has the advantage of
not being textual replacement.

Gerhard
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From forum: PIC - [PIC]

Re: accessing bits in a structure like an array

2009-11-25T09:46:02Z

Bob Blick escreveu:

> On Wed, 25 Nov 2009 14:26:01 +0800, "Justin Richards"
> <justin.richards@...> said:
>
>> Thanks Bob,
>>
>> struggling to understand here but I guess would use it like
>>
>> if (bitof(days.day,tm_wday))
>> {
>> do something
>> }
>>
>> and if tm_wday = 1 (monday)
>>
>> it expand to
>>
>> if(((bitv *)&(days.day))->b1)
>>
>> and now I am lost. What is bitv and how can I break it down further.
>>
>> Cheers Justin
>> 2009/11/25 Bob Blick <bobblick@...>
>>
>>
>>> You might be able to use this to help you access bits:
>>>
>>> #define _paste(a,b) a##b
>>> #define bitof(var,num) (((bitv *)&(var))->_paste(b,num))
>>>
>
> I didn't write it, but it's just a preprocessor construct that allows
> you to treat bits within a variable similarly to an array and you don't
> need to use separate getters and setters. So you can do something like
> this:
>
> if ((today==MONDAY) && (bitof(days,MONDAY)))
> MondayTask();
>
> and this would also work:
>
> if ((menuitem==MONDAY) && (ButtonPress()))
> bitof(days,MONDAY) = 1;
>
> I was really sleepy when I saw your first post so I don't remember what
> it was exactly you were doing, but having this as an option for you may
> work out somewhere.
>
> Cheerful regards,
>
> Bob
>

It appears that Justin needs the bit-index to be variable. If so, the
macro won't work because the macro is expanded at compile time and need
the bit number to be a constant.

Best regards,

Isaac
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From forum: PIC - [PIC]

Re: accessing bits in a structure like an array

2009-11-25T09:16:46Z

On Wed, 25 Nov 2009 14:26:01 +0800, "Justin Richards"
<justin.richards@...> said:

> Thanks Bob,
>
> struggling to understand here but I guess would use it like
>
> if (bitof(days.day,tm_wday))
> {
> do something
> }
>
> and if tm_wday = 1 (monday)
>
> it expand to
>
> if(((bitv *)&(days.day))->b1)
>
> and now I am lost. What is bitv and how can I break it down further.
>
> Cheers Justin
> 2009/11/25 Bob Blick <bobblick@...>
>
> > You might be able to use this to help you access bits:
> >
> > #define _paste(a,b) a##b
> > #define bitof(var,num) (((bitv *)&(var))->_paste(b,num))

I didn't write it, but it's just a preprocessor construct that allows
you to treat bits within a variable similarly to an array and you don't
need to use separate getters and setters. So you can do something like
this:

if ((today==MONDAY) && (bitof(days,MONDAY)))
MondayTask();

and this would also work:

if ((menuitem==MONDAY) && (ButtonPress()))
bitof(days,MONDAY) = 1;

I was really sleepy when I saw your first post so I don't remember what
it was exactly you were doing, but having this as an option for you may
work out somewhere.

Cheerful regards,

Bob

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