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1  Using Arduino / General Electronics / Re: Looking for a collection of schematics for learning on: July 24, 2014, 11:45:43 am
I have looked at the learning section, but didn't look like there were easily downloaded schematics there.

Hmm, I usually just right-click the schematic image and choose either 'Copy Image' or 'Save Image as'

Oh well.

Thanks for the search.
2  Using Arduino / Project Guidance / Re: DIY Rev Limiter using Inductive Pickup on 2 Stroke Carbureted Engine on: July 24, 2014, 11:38:01 am
You might be able to just use an N-channel MOSFET to short the output of the trigger coil to ground.

But 2k-4K RPM?  That engine does not even begin to make any power until about 8K-9K RPM.  Would the clutch even engage in that range?
3  Using Arduino / Project Guidance / Re: Weather Sensor Project on: July 24, 2014, 11:22:55 am
A DHT22 will give you both temperature and humidity and they are cheap and accurate.

What kind of precision do you need for the pyranometer?  Would a simple CDS photocell do the trick?  Dirt cheap and easy to interface.

I have no personal experience with IR distance sensors, but there are simple to use HC-SR04 based ultrasonic sensor modules available for about $4.  Lots of software examples too.  You just need to use a hood or something like that to keep it dry outside
4  Using Arduino / Project Guidance / Re: Relying on Arduino internal input protection against high voltages on: July 24, 2014, 11:08:21 am
I'll probably get trounced for this, but I'd say go for it and try it out.  The worst that can happen is you would damage a $3 chip.

Also, keep in mind that if your series resistor is too high, the input leakage current may affect your measurements, however you can probably compensate for that.

A better approach might be to use a simple voltage divider that brings the maximum expected voltage down to under 5V.
5  Using Arduino / General Electronics / Re: Looking for a collection of schematics for learning on: July 24, 2014, 10:57:38 am
There are schematics for a lot of the examples.  Plus everything I have looked at in the hardware section of the Playground has a schematic.

All in all, there are lots and lots of schematics in that section.
6  Using Arduino / General Electronics / Re: Looking for a collection of schematics for learning on: July 24, 2014, 10:46:59 am
Did you investigate the 'Learning' menu at the top of the forum page?
7  Using Arduino / General Electronics / Re: ENC28J60 not powering up on: July 05, 2014, 12:10:40 pm
The ENC28J60 requires far more current than will pass through that 10K resistor.  You need to add 3.3V LD regulator coming off the 5V.

If I am not mistaken, and ENC28J60 driving a standard magjack will draw over 300ma.
8  Using Arduino / General Electronics / Re: reason for no on/off switch on arduino? on: July 03, 2014, 10:51:21 pm
1) I don't see it that way, I just don't see the merit of using a shunt for a power switch (in this context or probably any other).
Why get so worked up? It's not as though the "Arduino gods" give a monkey's what I think and will pan your most excellent idea based on my comments.
It's simple, cheap and easy to use.  Of course, this does not cover Fungus' application of swapping it on and off for every wire or other change (ad minutia) you make.  However, I have boards that have the facility and it really is handy to cut the power when you need to.  No additions required.  If this is really confusing you and our Spanish compatriot, I could arrange a video on how the whole complicated and outrageously difficult to fathom thing works.

2) I don't get the inference. How does losing a shunt make anyone stupid?
Look up the word 'facetious'.  It applies to the comment.
9  Using Arduino / General Electronics / Re: reason for no on/off switch on arduino? on: July 03, 2014, 01:09:10 pm
A jumper placed at the right point in the circuit would cost $0.03.  Probably less in the quantities they make Arduinos.
Pulling a little jumper off the board then putting it back on every time I change a wire would annoy me intensely.

I could see you doing things that way.

So, unplugging your wall wart every time you change a wire, or reaching to toggle a soon to wear out switch every time you change a wire is a real improvement?

Okay, you win.
10  Using Arduino / General Electronics / Re: reason for no on/off switch on arduino? on: July 03, 2014, 01:01:52 pm
And that would lead to another question that would be asked over and over and over:
"I lost my little do-hickey. Anyone know where I can get more?"

Anybody who needs a switch can rig one up.

They can rig up a switch but they can't take care of a shorting block?

Oh, right.  I almost forgot 2-things:
 1) Thou shall never speak against the design of the Arduino gods, for it is flawless.
and
2) People who buy genuine Arduinos are really that stupid.

You know, I'm no genius (I'm sure you'll agree with that), but I've... a) never lost a jumper off the boards I have,  and b) Long ago I bought a big bag of them on eBay for about $2 for the time I should ever need one.
11  Using Arduino / General Electronics / Re: reason for no on/off switch on arduino? on: July 03, 2014, 06:12:53 am
A jumper placed at the right point in the circuit would cost $0.03.  Probably less in the quantities they make Arduinos.
12  Using Arduino / General Electronics / Re: type of board on: May 24, 2014, 08:26:13 am
RedBot uses an Optiboot bootloder, so choose Arduino Uno.
13  Using Arduino / General Electronics / Re: Circuits for Solenoids and LED's with 5V / 15V power supplies on: May 24, 2014, 07:34:35 am
You also need a current limiting resistor on the LED. Maybe 1K ohms.  The LED is also drawn in backwards and will never light it it's installed that way.  If it's installed the other (correct way) that could be why you are seeing a short.  So put a resistor in series with it.
14  Using Arduino / General Electronics / Re: Placing a via on a pad in Eagle on: May 24, 2014, 07:22:20 am
I'm not sure how to do this in Eagle, but in DipTrace it is easy.  I do it very often to create a thermal path to the bottom of the board for better heat sinking.  BTW, yo can get DipTrace for free if your making small boards (less than 300 pins).

Can you not just add the pad to the GND net then, as already suggested, connect it to the GND pin of the IC on the pattern?
15  Using Arduino / Microcontrollers / Re: Arduino Tre Price on: April 01, 2014, 01:41:14 pm
$23 to ship with Global Shipping: http://www.ebay.com/itm/181366863940
Well, a Fluke meter in a hard case is a far cry from a Arduino Tre.  $23 is not half bad for that.  But I get your point.  Still there is a good choice in that group you present.  That's what I mean.  So It costs $23 to have a Fluke meter in a hard case sent to Spain.  Not $60 or more, as choosing those would be foolish (like those that choose to pay SprkFun $2 for an LED).

I'm in Spain. I've ordered over 500 things on eBay, I think only two of them never turned up.

That's why I mentioned Spain.  Honestly, I don't know what to tell you Fungus.  Not sure if the items went 'missing' in the system, or if the recipients were not being all that honest.  Either way, with the tiny mark-up on these things, there was no way I could sustain giving back the money on 25% of my shipments.  It's too bad, because the other 75% really seemed appreciative.
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