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16  Using Arduino / General Electronics / Re: PIR Interference on: August 29, 2014, 09:58:54 am
separate power supplies.
17  Using Arduino / General Electronics / Re: current consumption when 5V apply to input pin of Arduino on: August 29, 2014, 04:58:31 am
Well, basically I have 5V on the ATMEGA interrupt pin like this.  Just wondering if this wastes a lot of power, when the Arduino is in sleep.

a) No.

b) You can measure it and find out.

18  Using Arduino / General Electronics / Re: PIR false positives on: August 29, 2014, 03:46:56 am
With the sparkfun PIR motion sensor...

A what?


Passive Infra Red.

19  Using Arduino / LEDs and Multiplexing / Re: PWM controlled RGB LED Strip makes my speakers buzz on: August 29, 2014, 02:06:43 am
Let's hope not...because they're not logic-level and won't work properly.

You need something that starts with "IRL", not "IRF".

Nope, the first tutorial uses IRF. It worked for me even following the Adafruit tutorial, which recommends a STP16NF06 or a TIP120 transistor.

Conclusion: The tutorial is wrong.

Here's the datasheet: http://www.irf.com/product-info/datasheets/data/irfz44n.pdf

Check out the value for "RDSon" (third value, page 2).

It says "VGS= 10V", ie. You need 10V to fully switch it on.


20  Using Arduino / LEDs and Multiplexing / Re: PWM controlled RGB LED Strip makes my speakers buzz on: August 28, 2014, 02:11:24 pm
I'm using IRFZ44N MOSFETs, as shown in the first tutorial.

Let's hope not...because they're not logic-level and won't work properly.

You need something that starts with "IRL", not "IRF".

21  Using Arduino / Microcontrollers / Re: Does Arduino suports this Custom LCD? on: August 28, 2014, 11:01:30 am
Which controllers are most Commons in arduino, then I could search by its controller

It simply doesn't work that way.

If it's a bare LCD with "zebra stripe" connector then there is no "common controller".

Every LCD needs a custom PCB and controller chip. You're expected to provide that PCB yourself (or pay them to do it for you).

Bottom line: There is no way to buy that screen at that price and use it with an Arduino.

22  Using Arduino / Microcontrollers / Re: Programming attiny15L using arduino isp on: August 28, 2014, 10:50:10 am
Quote
I've recently acquired an attiny15

Use it to decorate your room...

The ISP programming isn't the problem, the problem is getting the IDE to work with the chip. Think of the hours it will take you then buy an ATtiny85 instead, they're well supported.


23  Using Arduino / General Electronics / Re: Will powerful Capacitor between 5v and Gnd damage the voltage regulator? on: August 28, 2014, 09:35:21 am
If you want to be 100% safe you can put in a comparator and a P-channel MOSFET.

When the capacitor voltage is high enough it should trigger the comparator and switch on the Arduino via the MOSFET .


24  Using Arduino / LEDs and Multiplexing / Re: Led Driver from Adafruit where to buy in Germany? on: August 28, 2014, 08:36:28 am
Shame on me smiley-grin
thx. actually I searched and found only watterott and they have only a servo control shield.

Try again: https://www.google.es/search?q=adafruit+in+germany

25  Using Arduino / LEDs and Multiplexing / Re: NEWBIE Q: Output power of Galileo per PIN on: August 28, 2014, 04:45:17 am
Try putting the LEDs the other way around. Connect the anodes to +5V and the cathodes to the Galileo pins. Turn the Galileo pin LOW to switch on the LED.
26  Using Arduino / General Electronics / Re: I2C and the Atmega328P on: August 28, 2014, 03:51:58 am
You could always delete these two lines from twi_init:

Code:
  // activate internal pullups for twi.
  digitalWrite(SDA, 1);
  digitalWrite(SCL, 1);

They aren't needed anyway if you use hardware pull-ups.

Yes, but as I noted earlier, you can't give the code to anybody else if you do that.
27  Using Arduino / General Electronics / Re: price range to produce a board yun based on: August 28, 2014, 03:50:57 am
Thanx but where can i find that?

In the same place as you found "General Electronics".
28  Using Arduino / General Electronics / Re: using a buck converter as constant current source on: August 28, 2014, 03:47:31 am
Regarding the price, LED drivers seem more complicated than such voltage regulators ?

They need a few more components and they tend to have a higher power rating.

Can't it be done with a little modification of such a converter?

Not economically. Between the cost parts and labor you might as well pay the extra $1.50 and get a pre-built one.

29  Using Arduino / Microcontrollers / Re: Does Arduino suports this Custom LCD? on: August 27, 2014, 01:53:59 pm
Hi.. I'm working at a project where I'm gonna need to order a custom lcd


No idea.

I think the people to ask are the people who make the LCD.
30  Using Arduino / General Electronics / Re: Auto-Power on/off circuit on: August 27, 2014, 09:26:06 am
I found online this schematic that follows my idea perfectly, but what is the diode for?  smiley-roll-sweat

Something to do with "Switch detect", but you don't need that.

(so you don't need the diode either)

nb. If you do it that way you need a P-Channel MOSFET

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