gmane.comp.hardware.microcontrollers.pic

[EE]:: Cree standards for LED testing

Apptech — 2008-07-25T08:18:26

Cree LED testing procedures. 24 categories for LED testing. Standards used and conditions. http://www.cree.com/Products/pdf/LED_Lamp_Reliability_Test_Standard.pdf

[PIC] Staapl

Tom Schouten — 2008-07-25T07:47:54

Hello folks, The Staapl project has come to a point where it is ready for public scrutiny. http://zwizwa.be/staapl Staapl is a collection of abstractions for (meta)programming microcontrollers from within PLT Scheme. The core of the system is a programmable code generator structured around a functional concatenative macro language. On top of this it includes a syntax frontend for creating Forth-style languages, a backend code generator for Microchip's PIC18 microcontroller architecture, and interaction tools for shortening the edit-compile-test cycle. Enjoy! Tom

Re: [PIC] Remote network sensors

Vitaliy — 2008-07-25T06:13:11

If dimensions are not a concern, it should be possible to use an off-the-shelf $20 wireless router connected to a UART/Ethernet module without hacking anything. Might be a good hack for some quick-and-dirty one-off applications. Vitaliy

Re: [PIC] Remote network sensors

William "Chops" Westfield — 2008-07-25T05:27:00

On Jul 24, 2008, at 2:44 PM, Alex Harford wrote: Hmm. Or any of the other wireless router platforms that has enough info out there to run DDWRT or similar, many way cheaper than the WRT54GL. (hackability at the HW level is likely to be variable, though. One of these days a clever HW verndor will stick some x2.54mm headers on the unused pins to target the (small but vocal) hacker market.) How ... sad. It's also sad that something like the lantronix WIPort contains an x86 class machine with significant memory, enough so that putting a PIC on the side is ... almost silly. You could consider using something like a Rabbitcore (http:// www.rabbit.com/products/CoreModules/index.shtml) where at least you get to USE the same CPU that runs the tcp stack. (less than $50 for ethernet, less than $100 for 802.11. Also a zigebee version.) You might also want to look at things like PDAs with wireless network connectivity. Some of those have significant free development environments, subst

[OT]:: Al Gore - A Generational Challenge to Repower America

Apptech — 2008-07-25T05:15:44

Some whacko has to post on this sooner or later. May as well be me :-). This belongs in TECH *BUT* I'm posting it in OT as we don't have the maturity to handle it in TECH at a noise level that is appropriate. If it gets out of hand here we'll have to trash the thread. If it gets ignored here, that's fine. This is a very recent 'speech' by Al Gore challenging the US (the title says America) to convert all US electricity generation to non-hydrocarbon dependent sources within 10 years. It covers more than that, but that's the core. There is the inevitably unavoidable rubbish content and some good ideas and thoughts. The ideas are not without merit but will probably meet with mindless scathing putdowns from his opponents & detractors and mindless adulation from his fans. In between the two it would be good if there could here be some useful sage and reasoned comments. One can hope :-). You can find the speech on zillions of sites by Gargoyling A Generational Challenge to Repower America or i

Re: [PIC] Remote network sensors

Vitaliy — 2008-07-25T04:25:17

Marcel, I'm glad you made the mistake. I have a feeling that the module you recommended will find its way into one of our products. So, thanks! :-) Vitaliy

Re: [PIC] Shopping at MASTERS 2008 -- pricelist

Vitaliy — 2008-07-25T04:17:22

Most likely too late to be useful, but here it is anyway: http://maksimov.org/masters_pricelist.pdf

[EE] question on a fall edge trigger

gardenyu — 2008-07-25T03:40:22

Hi: I'm designing a battery charger with a power factor correction pre-converter. This critical conduction mode PFC chip (L6562 from ST), has a so-called compensation network, so that when load changes abruptly, it will slowly modify the output power to realize a high power factor. But since mine is a charger, there is almost a constant load, thus this function is not really useful. My worry is: when the load is suddenly removed, the chip might be unable to respond fast enough. I wonder is there such a transistor circuit, which does nothing at no load or full load, but only outputs high when load is removed (fall edge)? This may involve some power, so I think simple flip-flops might not be useful. Thank you for any opinions. _________________________________________________________________ 使用 MSN 有问题怎么办？客服机器人来帮忙！ http://help.msn.cn/-- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mai

Re: [EE] FET question

Bob Blick — 2008-07-25T03:29:23

Listas de Correo wrote: I'm ready to suggest that when using the FET the voltage rises too slowly for the Rabbit to start. Can you test again using the FET but driving the gate manually, first with a jumper wire, and if that works, then with a resistor? Because if it starts with the jumper driving the FET but not the resistor, that is a risetime problem. Cheerful regards, Bob

Re: [EE] FET question

Apptech — 2008-07-25T03:26:20

Looks OK enough from the spec sheet curves. Looking at V across module with a scope at turn on may give some clues. An easy enough test is to try a high side driver. Disconnect FET drain from model gnd. Ground module gnd. Small pnp transistor with at least 500 mA rating (BC327 or similar) Beta of 100 at least at 500 mA. Emitter to V+ Collector to module V+ Base via say 470 ohms to FET drain. You now have a high side switch with good drive If that works it gives you a clue. If not then the clue is different but not so clear. I assume that you have the MOSFET gds connected OK :-). Russell

Re: [EE] FET question

Jinx — 2008-07-25T03:15:54

This d/s says 0.2R < at > 4.5V, 0.3R < at > 2.5V http://www.fairchildsemi.com/ds/FD/FDV305N.pdf Take a look at Figures 2 and 4, you might find that Ron is higher than you planned for If I'm asssuming correctly, quick look, and the normalised Ron is *1.1 < at > 3.5V and 0.5A, then that would mean actual Ron in circuit is 0.33R, so you'd be losing 0.450A * 0.33R = 0.15V. If so, that puts the voltage available for the Rabbit at 3.15V Can you bump up the regulator output a little ?

Re: [OT]:: Why most published research findings are false.

Apptech — 2008-07-25T03:09:13

Yes.o problem if that was the level of response. However, what does happen is that people get results which show with statistical significance that there is/isn't (choose one) something happening. People can/can't replicate their results (or can't/can) and people publish papers drawing all available conclusions (not necessarily in the same paper). At the very large scale there are correlations present between increased disease risks for workers in some industries that suggest that EM fields may have causal roles in such things. Some cell-phone/cancer studies show a clear linkage and others show none. All adds grist for the subject line of this email. Russell

Re: [EE] FET question

Jinx — 2008-07-25T02:55:33

Just curious - how did you come to be in this position ?

Re: [EE] FET question

Jake Anderson — 2008-07-25T02:56:35

The Fet itself might be ok with a 0 ohm drive but the PIC probably wont be ;-> you could well be asking for a few amps of drive current (for a very short time). I'm wondering given the OP is using a 5.6K resistor if the miller charge is turning the fet off again as the rabbit comes up to power (as somebody else said its probably charging some caps and asking for a few amps of current) To limit the initial current you want about a 170 ohm resistor and that should hopefully be stiff enough to handle any of that other weirdness that goes on with fets. Your sure the fet is into its saturated region at 3.3V gate drive? that's quite low, not impossible just uncommon is all. Don't know how it'll work with the rabit, but try sticking a 1 ohm resistor in line with it, might help reduce the switch on thump.

Re: [EE] FET question

Listas de Correo — 2008-07-25T02:51:48

I have tried connecting and disconnecting the ground wire of the rabbit, directly, to GND and it successfully starts every time. The 450 mA at 0.15 ohm represent a voltage drop of 0.0225 V, that is 0.68% of 3.3V, so the Rabbit should work with that voltage, shouldn't? I'm trying not to consider RF yet... On Thu, Jul 24, 2008 at 11:00 PM, Apptech paradise.net.nz> wrote:

Re: [OT] Dual SIM mobile phone

Roger, in Bangkok — 2008-07-25T02:36:13

In that scenario Tomás I suggest you wait until you get here. AIS is the only carrier (thank you Mr. Thaksin) license for dual SIM, and you have to set it up through them on their equipment. It's still technically unlawful to import any communications device to Thailand without a special permit and license. That's not often enforced, but the penalties are too high and the work arounds too easy to ignore with any wisdom. You will find that most people simply carry 2 or more cell phones rather than draw attention to themselves and raise unnecessary questions:-) Regards/Roger, in Bangkok On Fri, Jul 25, 2008 at 6:21 AM, Tomás Ó hÉilidhe lavabit.com> wrote:

Re: [OT]:: Why most published research findings are false.

Tomás Ó hÉilidhe — 2008-07-25T01:04:19

Apptech wrote: Well if the guinea pigs grow an extra head, or if they start walking into walls, then I think it's fair to speculate that it's caused by the mobile phones. (Assuming of course, in the absence of mobile phones, they don't grow extra heads or walk into walls).

Re: [EE] FET question

Apptech — 2008-07-25T02:00:55

FET should tolerate a zero ohm connection from PIC. Try this. - Set up system as described. - Add switch across FET drain-source. - Open switch - Enable system via FET. - Close switch. IF it works under that condition the FET is suspect as an on switch. FET should have about 0.15 ohm on resistance as described. Should be OKish although the module spec is 3V3 +/- 5% so you are outside that range at 450 mA. If it fails to work then the system is probably being disabled in some manner by the load side open switch. eg having the module connected to Vdd and stray paths from I/O to ground may do funny things to it. Also: RF may be getting into FET. All bets off if that happens :-). Russell

Re: [EE] FET question

Listas de Correo — 2008-07-25T02:10:47

Unfortunally, we already have 100 boards made. We can make small changes, like putting a FET on the high side of the rabbit, but making big changes will be difficult. I will see tomorrow, while I'm at the office, if it is possible to change the layout easily from low side switch to High side switch. by the way, if I connect the rabbit directly to ground (or with a switch or a relay) it works just fine. So, the problem is with the MOSFET... Regards On Thu, Jul 24, 2008 at 10:43 PM, Spehro Pefhany interlog.com> wrote:

RE: [EE] FET question

Spehro Pefhany — 2008-07-25T01:43:12

That's not weird, it's expected. The module probably has a bunch of bypass capacitors and you're momentarily killing the supply charging them. I suggest a separate regulator with shutdown input is probably the best way to handle this (effectively a high-side switch with current limiting) The problem with switching the low side is that any logic pins that connect to the PIC or whatever could get pulled way below "ground" from the perspective of the the Rabbit module (eg. the PIC is "low", a great deal of current will flow through the protection diodes on the Rabbit module, possibly damaging it or causing latchup which would result very quickly in damage due to high currents. Spehro Pefhany --"it's the network..." "The Journey is the reward" speff< at >interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com

Re: [EE] FET question

Richard Prosser — 2008-07-25T01:09:58

2008/7/25 Jinx clear.net.nz>: Or even a toggle switch? RP