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1  Using Arduino / General Electronics / Re: Temperature maonitor for reflow on: April 18, 2013, 10:13:29 pm
I don't use a thermometer. When the solder reflows, it's done!
2  Using Arduino / Project Guidance / Re: Hi all can any one help a newbie on: March 24, 2013, 01:58:58 pm
Have you looked at the project notes of the video you posted?

parts, code, ect all there.
3  Using Arduino / Project Guidance / Re: trust ebay new arduino for beginner? on: March 23, 2013, 09:45:55 am
Whichever route you take, please do not purchase a board from eBay that displays the Arduino logo / trademark.
As a matter of curiosity, how can you tell this
 is not authentic? What was the tip off?

I'm also curious about this, especially since it is shipped from the US, not china.
4  Topics / Product Design / Re: sourcing parts help on: March 04, 2013, 11:12:03 am
Tayda is great for resistors, crystals, power jacks, LEDs, pin headers ect.

I do have a problem with their tact switches though... Lots of bouncing, missed presses and double presses. Definitely a much cheaper variety then what's at Digikey.
5  Using Arduino / General Electronics / Re: Arduino error in light sensor circuit on: January 29, 2013, 10:09:37 am
It's hard to follow the wires and we don't know what components you have there.

A proper schematic would be much better.
6  Using Arduino / General Electronics / Re: Arduino Due consumption on: January 29, 2013, 10:07:12 am
Do you mean you will have a load on each pin that draws 50ma?

If that's the case, the Due can't do that. Each pin is only rated for 3 or 15ma, depending on which pin. Also, the total current "output" of the entire Due is 130 ma. Try and draw more than that and you've just toasted your due.

It might help if you explain what load you want the Due to contol. Then someone can offer suggestions on how it can safely be done.
7  Using Arduino / General Electronics / Re: Small power source for one century on: January 27, 2013, 09:04:21 pm
The one thing you won't run out of in the next hundred years is curious people.
Reminds me of when my brother was little, he made a small wooden box with a slot in the top. He wrote "Insert Coin Here". Of course when ever we had guests over, they all had to insert a coin to see what happens  smiley-lol
8  Using Arduino / General Electronics / Re: Small power source for one century on: January 27, 2013, 02:17:43 pm
Have a little crank on the outside of the time capsule that turns a generator and charges a battery. Put a sign that reads "Please turn crank".

Someone ought to turn it within 100 years. smiley-grin

On a serious note, if you can sleep your processor and it uses 0.35 uA, it would require a 306.6 mAH battery. This assumes a zero internal discharge rate, and some form of battery chemistry that can last 100 years.
9  Topics / Device Hacking / Re: My DIY solder paste stencil on: January 18, 2013, 08:25:26 pm
Can you cut out pads for a TQFP with a knife?
10  Topics / Device Hacking / My DIY solder paste stencil on: January 18, 2013, 08:20:58 pm
I've looked for a diy way of making a solder paste stencil online. I couldn't find anything simple. There are lots of examples of using a thin copper plate, then etching away the holes. I thought I'd try something else.

I started with a thin piece of plastic from a food container. It's clear and 0.007" thick. Then I overlaid a printout of the PCB pads, and drilled 1.2mm holes through the template and the plastic. The hard part was keeping the drill from wandering. I also had to "clean up" the plastic holes as there were a lot of burrs.

I tried some 0.8mm holes too. Some worked, others I didn't get clean enough after drilling. I don't know if I can drill holes suitable for a TQFP, but I might have to give it a try. There was some minor smudging which seemed to be worse after the first board when the stencil was clean. I just fixed up the smeared paste with some tweezers before placing the components.

The photos below are of the stencil, the solder paste on the board, and the finished job. The resistors are size 0805.

Not bad for an afternoon of DIY  smiley-mr-green

edit: sorry for the huge pictures. On the plus side, you can see the granules in the solder paste!
11  Using Arduino / Project Guidance / Re: Charging 3.7v 165mAh LiPo battery on: January 17, 2013, 06:21:50 pm
I don't think you can safely or reliably recharge LiPos without a dedicated LiPo charger circuit. The charger has to monitor when the cell is full and stop the charge to prevent damage.

Someone more familiar with charging ICs may be able to recommend something.
12  Using Arduino / General Electronics / Re: Is there non-static saran wrap? I've gotten two ebay IC shipments saran wrapped. on: January 17, 2013, 06:16:06 pm
I once ordered some Atmega8 TQFPs from Tayda. They came loose in a little ziploc bag.

Then I ordered some Atmega328 TQFPs from Digikey. They came in a sealed, static-proof bag with the packaged date written on. There was a sticker that said "Use within 24 hours of opening". Inside the bag was a humidity monitor, and bake instructions depending on the relative humidity.

...I thought that was a bit overkill  smiley-eek  The parts work fine from either place.
13  Using Arduino / General Electronics / Re: Connecting Canon T3 to Arduiono. on: January 16, 2013, 05:35:42 pm
There's a library for that!
14  Using Arduino / General Electronics / Re: Connecting Canon T3 to Arduiono. on: January 16, 2013, 03:03:23 pm
I know a T3i, 60D, and XSi do not need a focus trigger. I would guess a T3 does not either.
15  Using Arduino / General Electronics / Re: Best way to regulate 4.2v to 3.3v (question) on: January 16, 2013, 11:38:54 am
A silicon diode in series will drop the voltage by about 0.7 volts.
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