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571  Community / Exhibition / Gallery / Re: Simple Colour Change Lamp on: February 10, 2014, 10:24:44 am
I figured it's kinda pointless seeing it in daylight... so I just switched it on (it's 1am, plenty dark enough i suspect)



oh and just to explain... I'm using 2n2222's  smiley-grin   and no "current regulation"  each npn can deliver around 800ma, so I use a 68 ohm resistor to the base pin for each segment, this rougly supplies 120ma per color which is well within spec of the transistor... I purposely kept it low knowing that when the LED heats up, i expected the current to rise up to 200 maybe 300ma, in which case it's well within spec of the 800ma limit of the transistor AND within the 300ma per RGB channels from the 10 watt.

So, 120ma * 3 * 5 =  1.8amps or 21watts.

The multimeter reads 1.8 - 1.9 amps...

Now, because I have no current limiting resistor on the emitter/collector side of the LED, it relies just on the 68ohm resistor, I originally was going to use something like a 30-40ohm resistor and 1/4watt was not up to the job, so i stuck with the 68 ohm resistor and *hoped* that once the LED's warmed up, it would draw more current to get to the 300ma mark.

And (as I suspected) ... No.

The heatsink keeps the LED's cool and sadly (even in 45c / 100f+) heat, still no... maybe if i run it for a few hours instead of 30 - 40 minutes the current will slowly creep up? - good because I like bright.

next time i'll use 1/2watt resistors and push the 50watt boundy, as it is 21watts is bright enough.

572  Community / Exhibition / Gallery / Re: Simple Colour Change Lamp on: February 10, 2014, 09:47:31 am
Over the weekend, I finally got around to finishing a similar thing, except i used 5 of them... potentially it can supply over 50 watts of light but I decided to limit the current, it pulls around 2amps at 12v (or 24watts) and decided that's bright enough.



But i also did what you did using an attiny85 for the bedroom, they certainly beat 5mm LED mood lights you get from shops..
573  Community / Bar Sport / Re: A broken Arduino... on: February 10, 2014, 08:56:15 am
Probably not worth doing... but you could replace the voltage regulator and possibly one of the ceramic smd caps and bring it back to life...

i'm amazed it works at all, i've killed 2 clones after supplying just 12v! (with no load either)
574  Using Arduino / Project Guidance / Re: Forty-two Unos in a row on: February 10, 2014, 05:47:41 am
The nrf radio module might be an option, each one could listen and broadcast to everyone else, it should save you on running a lot of cable, and I guess more options when it comes to controlling them.

http://www.ebay.com.au/itm/2-PCS-NRF24L01-2-4GHz-RF-Wireless-Transceiver-Module-for-Arduino-/230791084009?pt=AU_B_I_Electrical_Test_Equipment&hash=item35bc3877e9&_uhb=1


Bulk buy, you should get them to around a dollar a module.
575  Using Arduino / Project Guidance / Re: Can I power my Arduino with a MintyBoost? on: February 10, 2014, 03:59:44 am
I doubt any harm will come... but it could do with some filtering to smooth out any voltage fluctuations.

576  Using Arduino / LEDs and Multiplexing / Re: Is it possible to control thousands of leds with arduino? on: February 08, 2014, 11:17:51 pm
Unless you design a pcb and use the tracks, prototyping one that uses just 100 leds would be a pain in the arse.

Take a look at addressable leds (which have the shift register embedded in the led)
577  Using Arduino / Project Guidance / Re: Controlling devices connected to arduino uno+bluetooth through android. on: February 08, 2014, 05:19:36 pm
Well yes, once you establish a connection to your arduino via a bt module,  you use uart via a hard/soft serial port, then it's a case of parsing the data..

Simplicity send 'A' from android

GetData .. serial.read. .
If (byte=='A')
  digitalWrite (pin, HIGH);

Etc
578  Community / Bar Sport / Re: Where to go to start developing apps? on: February 08, 2014, 07:05:06 am
Apple was first at what?...

I never said anything about being first!
579  Using Arduino / Project Guidance / Re: Controlling devices connected to arduino uno+bluetooth through android. on: February 08, 2014, 06:23:15 am
Bluetooth on android works via an intent, it's not newbie friendly. .

http://developer.android.com/guide/topics/connectivity/bluetooth.html

580  Using Arduino / Project Guidance / Re: How to read a square wave using arduino on: February 08, 2014, 06:16:14 am
By feeding it into an analog pin, then measuring the value you get...

Providing the 555 gives a voltage out less than 5v or use a voltage divider.
581  Using Arduino / Programming Questions / Re: Want Relay with Button and Time Limit, not sure if loop will work correctly... on: February 08, 2014, 05:53:08 am
The delay freezes the program.

The none delay works like someone using a stop watch, so you get the millisecond count and at some point you get it  again, you compare the two time stamps (oldtime-newtime) gives how long it's been running for, be 5 seconds or 5 hours.

But where's the code?
582  Community / Bar Sport / Re: A broken Arduino... on: February 08, 2014, 05:47:59 am
A badArduino?

Ooo a badassArduino (uno rev 6? )
583  Community / Bar Sport / Re: Where to go to start developing apps? on: February 08, 2014, 05:46:26 am
Java for one objective c (why?? Whyyy apple why!) For the other.

I decided to learn java myself and develop for android, I hate the way java is structured, all the try, excepts, crashing if you don't give it the right permissions, the fact that the app will terminate if it becomes unresponsive,  the lack of asynchronous sockets (you need to thread everything) just well I hate it but it's an evil I must learn!

If it had windows style messaging life would be nice..  so the ANR and how everything must be threaded or it can crash is a downer.....


To answer your question.... if you want a write once, compile once and then distribute it to both android and ios, take a look at delphi XE5 I like it but my computer is getting on the tad old side so I stuck with java (for now) but Delphi will allow you to write apps for all the major platforms without you lifting a finger...

But, it's bloated, all of it's runtimes are embedded into the apk file, while it's true you could knock up a program in 5 minutes vs a few hours in Java, it comes at a cost in filesize...

When I make a fortune from java, I'll buy a super computer just so I can compile and run apps from delphi xe5 smiley



584  Community / Bar Sport / Re: A broken Arduino... on: February 08, 2014, 05:33:23 am
Oh cool.... I was actually getting excited at the thought of a 386 awwwww!.

I'm almost finished wiring up a small project and more than 2 shift registers leads to spaghetti junction  smiley-eek-blue
585  Community / Bar Sport / htc phone kills?! on: February 07, 2014, 11:35:35 pm
But seriously?

I'm not falling for it, maybe the charger malfunctioned or the charging ics failed leading to the lithium battery venting hence his burns...

But electrocution?
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