[QUOTE=DrLuke;35091066]Only one row will light up at a time, so you calculate the individual LED resistance you need and put one on every column.[/QUOTE]
You mean to calculate the resistance for each row?
[editline]11th March 2012[/editline]
Also, I bought some basing components so I have something to work with in the beggining.
These include:20x200 ohm resistors
50xRed LEDs
4x1k pots
1xBreadboard
6 m of conducting wire
Anything else I should get to have more possible projects avaible?
The resistor size you need to give a desired current through a LED is given by:
R = (V - Vd) / I
V being the supply voltage.
Vd being the voltage drop, if you have multiple LEDs in series the voltage drop is the sum of each LED
I being the desired current (usually 10-20mA)
If the total voltage drop is close to your supply voltage then you will have a hard time picking a resistor since R will become very small, alternatively you can forgo the resistor if this is the case since the wire and LED resistance will limit the current itself, however this is not as stable or accurate as using a resistor.
If you're driving LEDs from a microcontroller or anything else really that consumes more than a few mA the best option is to use a transistors as a buffer, either a BJT or MOSFET transistor.
MOSFETs are generally preferable as they do not require a resistor as BJTs do.
I'd suggest also buying a resistor selection, capacitors, more pots, transistors, etc because at the moment there is not a lot you can do with them parts.
[QUOTE=Kastro;35091160][B]im trying to make 12x4 LED board with arduino duemilanova. i dont think it have got enough pins for it, and arduino can power up all this LEDs on the same time. can you guys please help?
this image shows how it will work[/B][/QUOTE]
As DrLuke said, transistors.
Also I suggest you read up on multiplexing.
[QUOTE=Chryseus;35092523]The resistor size you need to give a desired current through a LED is given by:
R = (V - Vd) / I
V being the supply voltage.
Vd being the voltage drop, if you have multiple LEDs in series the voltage drop is the sum of each LED
I being the desired current (usually 10-20mA)
If the total voltage drop is close to your supply voltage then you will have a hard time picking a resistor since R will become very small, alternatively you can forgo the resistor if this is the case since the wire and LED resistance will limit the current itself, however this is not as stable or accurate as using a resistor.
If you're driving LEDs from a microcontroller or anything else really that consumes more than a few mA the best option is to use a transistors as a buffer, either a BJT or MOSFET transistor.
MOSFETs are generally preferable as they do not require a resistor as BJTs do.
I'd suggest also buying a resistor selection, capacitors, more pots, transistors, etc because at the moment there is not a lot you can do with them parts.
As DrLuke said, transistors.
Also I suggest you read up on multiplexing.[/QUOTE]
So what value resistors , capacitors, pots and transistors, and how many of each should I get?
[QUOTE=Levakama;35092578]So what value resistors , capacitors, pots and transistors, and how many of each should I get?[/QUOTE]
[quote=Chryseus]
The resistor size you need to give a desired current through a LED is given by:
R = (V - Vd) / I
[/quote]
For resistors get a large selection (you can never have enough), preferably 10 each of the E12 series, you can get packs from places like bitsbox, ebay, etc.
As for capacitors again get a selection of them, at the minimum you want a good number of electrolytic capacitors from 1uF or 1000uF, preferably rated for at least 25V.
Ceramic capacitors are also handy, two dozen or so ranging from 10pF to 100nF should do the job, at least to begin with.
Get a bunch of pots, look for cement trimmer pots (usually multiturn) as these are cheaper, the values are not critical just get some between 1k and 1M ohm.
As for transistors just get some general purpose NPN and PNP Bipolar junction transistors such a the BC337, BC327, 2N3904, 2N3906, 2N3705 or 2N4403.
Get some MOSFETs as well, I can recommend the 2N7000.
Aside from this grab a few 555 timers, LM324 op-amps or similar, 1N4007 rectifier diodes, 1N4148 signal diodes and anything else that looks interesting to you such a LDRs, thermistors, hall-effect sensors, etc.
Lonewolf, how far can that little thing transmit? I am wondering because I think there are laws barring high range transmitters, correct? It's a shame because I wanted to make a radio jammer/thing I can talk on while people play music in their cars.
[QUOTE=Chryseus;35092697]For resistors get a large selection (you can never have enough), preferably 10 each of the E12 series, you can get packs from places like bitsbox, ebay, etc.
As for capacitors again get a selection of them, at the minimum you want a good number of electrolytic capacitors from 1uF or 1000uF, preferably rated for at least 25V.
Ceramic capacitors are also handy, two dozen or so ranging from 10pF to 100nF should do the job, at least to begin with.
Get a bunch of pots, look for cement trimmer pots (usually multiturn) as these are cheaper, the values are not critical just get some between 1k and 1M ohm.
As for transistors just get some general purpose NPN and PNP Bipolar junction transistors such a the BC337, BC327, 2N3904, 2N3906, 2N3705 or 2N4403.
Get some MOSFETs as well, I can recommend the 2N7000.
Aside from this grab a few 555 timers, LM324 op-amps or similar, 1N4007 rectifier diodes, 1N4148 signal diodes and anything else that looks interesting to you such a LDRs, thermistors, hall-effect sensors, etc.[/QUOTE]
Thanks a lot!
That was the sort of response I was looking for.
For LEDs 220 Ohms is a good allrounder value.
[QUOTE=DrLuke;35094051]For LEDs 220 Ohms is a good allrounder value.[/QUOTE]
You should note that that is on 5 volts (or less).
Any idea what can I do with 100 christmas lights?
I ordered 100 RGB LEDs (it had 3 leads on the pictures and even on the schematics) and got 100 LEDs with 2 leads which blink in patterns and change colour automatically. They are stuffed with SMD components.
What is the best way to dispose of them?
Why didn't you file a complaint at the vendor? Maybe they just accidentally sent you the wrong item.
Also make an actual chain of christmas lights out of it.
[QUOTE=Kastro;35091160][B]im trying to make 12x4 LED board with arduino duemilanova. i dont think it have got enough pins for it, and arduino can power up all this LEDs on the same time. can you guys please help?
this image shows how it will work[/B]
[IMG]http://itseecan.com/IMG_3615.gif[/IMG][/QUOTE]
Charlieplexing is working good for me.
[QUOTE=DrLuke;35100331]Why didn't you file a complaint at the vendor? Maybe they just accidentally sent you the wrong item.
Also make an actual chain of christmas lights out of it.[/QUOTE]
They haven't. They claim it was in the description that the images and the datasheets do not resemble the item.
They'd be happy to replace it, given that the package is still sealed and I will send it back.
$10 shipping charges for a $6 item? Fuck no.
Does it matter what size of capacitors do I get?
I see many choices concerning the dimensions.
[editline]12th March 2012[/editline]
Would this suffice?
[IMG]http://i42.tinypic.com/2aj2wk.jpg[/IMG]
£0.69 for 10 resistors?, seriously overpriced.
Use a decent store like bitsbox or anything else listed in the op, unless you enjoy paying out ridiculous sums for components.
Also as I said the first time, get a resistor and capacitor pack because you're missing a lot of values, sure you can stick some in series / parallel but that's just a pain the arse.
Sorry if I sound a bit like a dick but I don't like to see people wasting money when there are much better alternatives available.
Ah, I did not notice that they sell packs at the shop I was using.
I can not use bitbox because the shipping would make the price way higher.
Can I add you on steam?
[QUOTE=Levakama;35108825]Can I add you on steam?[/QUOTE]
Of course.
Well, 42.500MHz on a 50MHz bandwidth analog scope sure looks funky.
[url=http://i.imgur.com/z02yg.jpg][img]http://i.imgur.com/z02ygl.jpg[/img][/url]
(200mV/div @ 0.05 µs/div)
A friend and I have been working on a a engine simulator, we were using an old techtronics 100MHz quad channel to record timing signals from variable reluctance sensors in the distributor just last night.
[t]http://i924.photobucket.com/albums/ad84/tw34kpics/Electronics-Tech/424467_314102988645120_100001362652581_810796_941900462_n.jpg[/t]
[quote]
18:29 - Asgard - ლ(ಠ益ಠლ): okay
18:29 - Asgard - you know a schematic or some hints to building a circuit with a switch that controls different LEDs?
17:39 - Asgard - ლ(ಠ益ಠლ): oh and it shouldn't involve a 555 timer because I -still- don't have one :P
18:37 - Chryseus: hmmm
18:37 - Chryseus: like a light switch ?
18:37 - Asgard - ლ(ಠ益ಠლ): oh wow...
18:38 - Chryseus: :-V
18:38 - Asgard - ლ(ಠ益ಠლ): that was.... quite the insightful moment....
18:38 - Chryseus: :-D
18:39 - Asgard - ლ(ಠ益ಠლ): you can go ahead and post that in the electronics thread if you want :P
[/quote]
Sometimes the answer is staring us right in the face.
[img]http://i55.tinypic.com/xqdn34.png[/img]
Much better picture of the whole thing, including my self made ICSP connector.
[QUOTE=DrLuke;35137952][img]http://i51.tinypic.com/30c84dy.png[/img]
It's... It's... ALIVE![/QUOTE]
Fuck yeah, dude, good job!
...What is it? :downs:
It's the signal generator for my teslacoil.
[QUOTE=DrLuke;35142703]It's the signal generator for my teslacoil.[/QUOTE]
So you're making a musical tesla coil then? Neat.
[table][tr][td][img]http://imgkk.com/i/1tse.jpg[/img][/td][td][img]http://imgkk.com/i/v210.jpg[/img][/td][/tr]
[tr][td][img]http://imgkk.com/i/yf7w.jpg[/img][/td][td][img]http://imgkk.com/i/-s6n.jpg[/img][/td][/tr]
[tr][td]Transferred that game controller into a slightly more permanent home and wired up the lights,
right now I've just got it set to turn off the light when the button is pressed, but I've got
individual control, so I can do whatever.[/td][td][img]http://imgkk.com/i/0lsd.jpg[/img][/td][/tr][/table]
What's the easiest way of controlling a microcontroller (MSP430 preferably but i do have an arduino board too) with an android device (serial communication preferably)?
Through a desktop computer.
[QUOTE=ROBO_DONUT;35144902]Through a desktop computer.[/QUOTE]
What? No, the android device is going to be on the device that's being controlled by the microcontroller.
[QUOTE=aydin690;35145044]What? No, the android device is going to be on the device that's being controlled by the microcontroller.[/QUOTE]
You asked for the "easiest way of controlling a microcontroller with an android device". Given the lack of information, my assumption was that you wanted to use the Android device as a sort of remote control.
It's not my fault if you didn't explain the problem clearly.
Get a bluetooth serial module for the MCU.
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