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1  Using Arduino / Project Guidance / Re: How far can I send a serial signal? on: September 15, 2014, 08:36:11 pm
Have a look at this http://digital.ni.com/public.nsf/allkb/2CABB3FD5CAF2F8686256F1D005AD0CD
You can do 50 feet at up to 1kbit but 120 is doable at lower data rates like 9600 but it all depends on noise how fast it can run.
2  Using Arduino / Project Guidance / Re: Powering a small "electromagnet" directly from an Uno? on: September 14, 2014, 08:43:47 am
If its 333 ohm its only going to use 15 mA but only thing I don't like is the wire in these things is enamel paint and a used one could easily break down and short. Why not pop a npn 12 cents then to chance a uC thats 4 dollars.
3  Using Arduino / General Electronics / Re: 3v Laser Power design, and why did they all suddenly blow out? on: September 13, 2014, 05:51:37 pm
Like Mike said all of them are not made the same" tricky" . Seeing the op said they have resistor on them tell us what it is.
From Mike link
Quote
Buy one that accepts an unregulated input voltage. Otherwise, you can still have problems even if you run the device from a regulated power supply. All laser pointers and most (but not all) modules will be of this type. However, if you get a deal that is too good to be true, corners may have been cut. A proper drive circuit will be more than a resistor and a couple of capacitors!

To confirm that the driver is regulating, start with an input near the bottom of the claimed voltage range and increase it slowly. The brightness of your laser diode should be rock solid. If it continues to increase even within the supposedly acceptable range of input voltage, something is wrong with either the laser diode (it is incompatible with the driver or damaged) or driver (it actually requires a regulated input or is incorrectly set up for the laser diode you are using). Stop right here and rectify the situation before you blow (yet another) laser diode!
4  Using Arduino / General Electronics / Re: Help Identifying Capacitors. on: September 08, 2014, 09:44:54 pm
I hate to say anyone wrong but the 275 volt cap is used on bower fans like you find in window AC and could be used on your motor too
5  Using Arduino / General Electronics / Re: Using Arduino digitalpin as a standalone switch on: September 07, 2014, 09:15:47 pm
Have a look at this http://electrosome.com/transistor-as-a-switch/
6  Using Arduino / Project Guidance / Re: Problem connecting Arduino Uno to Windows computer on: September 07, 2014, 09:07:23 pm
Or it;s not a windows pc it's a chome book
7  Using Arduino / General Electronics / Re: Wiring Capacitors in Series on: September 01, 2014, 09:07:34 pm
You have a supper capacitor that can hold a charge http://www.karlssonrobotics.com/cart/super-capacitor-low-esr-1f2-5v/?gclid=COPMjsy4wcACFZJr7AodU00Aqw
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Description: Yes you read that correctly – 1 Farad capacitor. This small cap can be charged up and then slowly dissapated running an entire system for hours. Combine two in series for 0.5F/5V. Do not over voltage or reverse polarize these capacitors.

And yes there 2.5 volt used like a fast charged battery in toys and stuff
DO not OVER Charge these they can and will hurt you. 2volts is a safe charge for them.

This baby can hold a lot of power
8  Using Arduino / General Electronics / Re: Ohm's Law. on: September 01, 2014, 06:16:57 pm
There really no crap it's simple ADC  is so miss understood on a micro it reads based on 0 to 1024 or is it 0 to 1023.
No there 1024 steps but that will not fit in 10 bit so we get the 0 to 1023.
So we are now trying to do math that's that has no error and the ADC of a arduino can be off more then the whole point of is it 1023 or 1024 it reads a range and tells you is value you'll never get a true math answer. Just a good as it gets is about it.

So that's where the debate comes in My math is closer to in this case Ohm's law   
9  Using Arduino / General Electronics / Re: Ohm's Law. on: September 01, 2014, 04:08:25 pm
Diversions come about when some one is wrong and has to be corrected.
Like your use of the word intensity, what does that mean in this context.
Maybe we reading waves  of power
10  Using Arduino / General Electronics / Re: PIR false positives on: August 28, 2014, 10:05:33 pm
It sure sounds like its floating on the output. But lighting will mess them up too
11  Using Arduino / Project Guidance / Re: How to power the Arduino from a UK light switch on: August 23, 2014, 09:21:42 pm
I'm just wondering  cause wire here is two wire too but your not counting the ground its sold as 14-2  and 12-2 for thing like wall outlets
and lighting. but you still have all three wires.

Have a look at this http://www.discovercircuits.com/Andy/Parasiticpowersupply.pdf
12  Using Arduino / Project Guidance / Re: How to power the Arduino from a UK light switch on: August 23, 2014, 08:50:11 pm
Absolutley not.

Lightswitches in uk no not have a neutral.

If you use the earth the very best situation would be you trip a leakage breaker if you have one.
They are not connected to lighting circuits in domestic situations any way.

Worst case various electrical devices in home will suddenly become live wrt local earth, FATAL.

So they just break the hot and don't bring the neutral in the box. There is ways of doing this but I wouldn't want some one with
no idea of whats in the switch box putting his hand in there they use higher voltage over there.
13  Using Arduino / Project Guidance / Re: Obstacle Avoiding Robot Help on: August 23, 2014, 01:55:35 pm
You got a lot of problems going on here. First off how are you driving the wheels ?
If your using two motors to move forward one side turns CW and one turns CCW  but that can be fixed in the wiring of the motor.
Or handled in code.
 Next thing you need to figure is ok im moving forward at high speed going to hit a wall how long does it take to stop before that happens.
We have to act on that to do one of two things low down or stop then figure new path to take in your case stop looks like what you want.
Then figure new path.

To help with the code need to see how you have it wired..
14  Using Arduino / General Electronics / Re: R5 on LCD broken? on: August 20, 2014, 09:34:12 pm
Two of mine are marked 222 for R5
15  Using Arduino / General Electronics / Re: R5 on LCD broken? on: August 20, 2014, 09:09:30 pm
Sorry your talking about the resistors on the back should of looked at your pic sure thats not part of the back light.
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