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556  Using Arduino / Microcontrollers / Re: [ATTINY85]Nothing but junk appears on my serial monitor... :( on: February 26, 2014, 05:25:46 pm
I just tested with 3.3 volts from arduino duemilanove and i get the same junk letters...with this code for example which uses the previous core i get this "ðððððððúððððððððûðððððððððððððððøððúððððððøððúððððððððð" in straight line.

Is there any problem that windows isn't in english language? I think i have tryied everything...

You need 5v...... 3v is no good for softserial!
557  Using Arduino / Microcontrollers / Re: [ATTINY85]Nothing but junk appears on my serial monitor... :( on: February 26, 2014, 08:12:05 am
Under 3.3v softwareSerial acts up (when powering the attiny85)
558  Using Arduino / Microcontrollers / Re: [ATTINY85]Nothing but junk appears on my serial monitor... :( on: February 26, 2014, 07:19:37 am
There are no hardware serial ports.

Use softwareSerial over 3v  (5v)
559  Community / Bar Sport / Re: whats with the attitude on: February 25, 2014, 08:38:00 pm
Lol I choose to be socially inept, I throw it like a switch on command smiley
560  Community / Website and Forum / Posting topic problem on Android. on: February 23, 2014, 09:14:08 pm
Everytime i make a new topic with Android, it takes me to the "Arduino is down forum, try again later" message with a nice pretty Arduino Logo...

This just me?
561  Community / Bar Sport / A Space Cannon, CERN style! on: February 23, 2014, 09:12:18 pm
I know kickstarter has a cannon project but I just had my own thought...

How about a CERN style cannon?  A 3 mile oval/circle of tubing,  the object goes in, then using a series of blasts or maybe a laser, bring the object to as fast as possible (eg firing a laser into some kind of dish mounted on the payload for space) as it speeds up while tracking it...

The other side of the 3 mile track a hydraulic system to lift a section of the blast tunnel up for a trajectory into space a few moments later the payload arrives and wooosh out into space it goes!

Doing it this way means you can gradually increase the speed (laser, electromagtic acceleration,  etc) until the speed needed is approached. 

What says you? smiley
562  Community / Bar Sport / Re: Whiplash from a topic search ! on: February 23, 2014, 09:17:18 am
just buy a magic 8 ball dude...
563  Community / Website and Forum / Re: Scum of the earth Spammers on: February 23, 2014, 05:40:07 am
Maybe it's time the forum became somewhat self regulating...

If 3 or more (different ip's) hit the 'report spam' button the post goes straight to a catchment area to be analyzed.
564  Using Arduino / General Electronics / Re: Transistor causing problems switching ground side of an LED on: February 22, 2014, 09:04:13 pm
And where and how do the resistors fit into this drawing?  smiley-eek-blue
565  Using Arduino / Project Guidance / Re: Resistor 2W with LEDs on: February 22, 2014, 11:11:09 am


Using a zener diode and a resistor combo like this could be an option, except you need a string of LED's...

(Fire is unlikely,  but fair enough lol)
566  Using Arduino / Project Guidance / Re: Pull down resistor not working as expected on: February 22, 2014, 10:47:32 am
Does this happen on other pins?

And you're using pinMode (7, INPUT); in setup ?
567  Using Arduino / Project Guidance / Re: Resistor 2W with LEDs on: February 22, 2014, 10:43:15 am
You are going to generate the same amount of heat with any linear regulator method.
If you want to reduce the heat then you have to use a switching regulator, there are a lot harder to make because you need a good layout on a PCB to keep the circuit stable.

Quote
And just to reiterate - using a current source for the LEDs, you do not need to feed them from a voltage regulator.
I think you are misunderstanding this statement.
Quote
So again, the LM317/7812s would go away.
No, you replace it with all those transistors that generate a constant current supply.

I would not endorse the advice given by cjdelphi

He  asked for suggestions... now get off your soap box
568  Using Arduino / Project Guidance / Re: Resistor 2W with LEDs on: February 22, 2014, 10:36:54 am
There is an even easier way....  but you take a bit of a risk as there's no current regulation.

Simply using 1 transistor per string of LED's, you'd bias the transistor with the right resistor value on it's base, and leave out the resistor between the collector and emitter, eg a 2n2222 npn (800ma rating) what (i and probably I alone) i'd do is place different resistor values on the base until you get 1/3rd or so the target current...  once you hit your 100/200/300ma mark (just use a multimeter if you wish to test it) use the same resistor value on each of the transistors.

Cons - current is not regulated, heat will make the current rise, so the trick is to get it roughly 1/3rd of the max current rating, so when the heat does rise, the LED will get brighter but it should hopefully stay within your max range.

Pros. only 1 transistor and only 1 resistor, and cheap.

The better the heatsink, the less likely current will fluctuate with heat, for example i use the same method for 10watt RGB's and it works flawlessly all day every day, i have had it working with 3watt RGB's too but the smaller the LED, the more noticeable the effects.

ie.. winter time, the LED is not as bright, in the summer time, it's 30% or so brighter.

But as pointed out, using a sense resistor, you can accurately measure the current and alter the current accordingly via PWM.
 
569  Using Arduino / Project Guidance / Re: Resistor 2W with LEDs on: February 22, 2014, 04:04:24 am
You could get away with just using a couple of transistors (and a sense resistor) and basically make your own regulator.. but it would be more work than an ln317 in current regulation mode.

570  Using Arduino / Project Guidance / Re: Arduino Uno running in a car on: February 22, 2014, 04:01:52 am
Do MOV (Metal oxide varistor) get produced for low voltage ?   - if the same principal applied to the 120/240ac versions but only in low voltage DC form, that could be used to protect the circuit from voltage spikes.

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