Hi guys,
I am new with Arduino. May I know where I could get relevant information about each components, like the internal resistance, voltage drop and required current of Transistor, Photoresistor and other components etc? These information will do a great help for me to design new circuit.
Thanks in advance 
From the manufacturer's datasheet. [u]Here[/u] is the datasheet for a 2N2222A transistor.
If you buy from a reputable supplier, you should get the manufacturer's part number so you can look it up. In fact, you should generally look-up the datasheet before you buy.
If you are new to electronics, you won't understand everything on the datasheet. If you don't know how transistors work, the datasheet isn't going to make sense. And, part of the trick is knowing what's important to your particular application and what's not. The datasheet for the Arduino's Atmel ATmega chip is over 600 pages so almost nobody studies the whole thing, you just look-up whatever you need to know.
I've been "getting started" for more than a few years. I still find myself messing up through not FULLY understanding EXACTLY what volts, amps and ohms are. And the real facts of exactly how current and voltage change, as you go around a particular circuit... particularly when there are parallel and serial elements to it... need close attention.
"Getting started" stuff about volts/ amps/ ohms at...
Hi,
is a good site for semiconductors, does not stuff you around or offer deals or want to fix problems with your computer that you didn't know about.
Tom......
I use Google for datasheets. In many cases the manufacturer (best) or a major vendor like DigiKey/Mouser/Seeed/Adafruit/SparkFun (second best) will show up with a datasheet in PDF form. The sites that gather datasheets (alldatasheet.com, datasheetcatalog.com, datasheets.com...) will make you jump through several pages of ads (which is how they make money) to get to the datasheet you want.
Also, get a fairly nice multimeter. This will let you measure voltage, current, resistance, and possibly capacitance/inductance for those components that you can't find a part number->datasheet for. See the EEVBlog Multimeter Buying Guide:
Hi HarrisLaw,
I too have been learing for many years, I left school in bottom grade, but now I'm 65+ and still trying new things, struggling with C, etc.
As it's been said, look up datasheets, you will not understand all that parametres and figures, but doing it yourself is the only way to really learn, mistakes we all make mistakes and the man that says he does'nt is a fool.
As johnW says a few good tools with help, especailly a good DMM (Digital Multi Meter).
Regards
Mel.
I now also have a good component tester which will tell me if I have plugged in a capacitor, resistor, inductor, NPN or PNP transistor, FET, thyristor or Triac. It does not however not make the tea which I am sure is an oversight.
As it is based on an Atmega328 I suspect the code is available somewhere as open source...
As it is based on an Atmega328 I suspect the code is available somewhere as open source...
You cannot make that assumption. The Atmel ATmega doesn't require that you release your code as open-source... It's a microcontroller chip with no more "rules" than any other microcontroller chip.
You don't have to open-source your Arduino code either, except there are some requirements if you use (or modify) the Arduino library (for example the stepper-motor library).
Using an open-source IDE/complier doesn't mean the code you develop is automatically open-source.
Hi ChilliTronix.
Yes I too have one of those. I wish I could get my hands on the code too, it's nice but! Does'nt always display the right units like 470000R for 470K, etc. But for £8.00 what can you expect?
I have had a look for the code but can't find anything, it would be good to change, etc. Perhaps as it's been said, it's just not available, if it was mine would I give it away??
Regards
Mel.
@Cactusface, that is the kiddie!
DVDdoug:
You cannot make that assumption. The Atmel ATmega doesn't require that you release your code as open-source... It's a microcontroller chip with no more "rules" than any other microcontroller chip.You don't have to open-source your Arduino code either, except there are some requirements if you use (or modify) the Arduino library (for example the stepper-motor library).
Using an open-source IDE/comaplier doesn't mean the code you develop is automatically open-source.
All true, but when you see exactly the same thing by half a dozen different manufacturers in slightly different forms you make the assumption that somewhere they are working off a common design... and that would imply open source.
I have found mention of it in an old thread but the code page where it was is no longer there... which is a shame.
Cactusface:
Hi ChilliTronix.
Yes I too have one of those. I wish I could get my hands on the code too, it's nice but! Does'nt always display the right units like 470000R for 470K, etc. But for £8.00 what can you expect?I have had a look for the code but can't find anything, it would be good to change, etc. Perhaps as it's been said, it's just not available, if it was mine would I give it away??
I have one of those as well - low cost, works well. I strongly suspect that it is a "knockoff" of this tester ("original" article):
http://www.mikrocontroller.net/articles/AVR-Transistortester
The writeup is in german, but google translate will work ok on it; schematics, binary and source are available.
What I believe to be a followup to that article is here:
http://www.mikrocontroller.net/articles/AVR_Transistortester
The following appears to be from the author's website - note that the link to the article he references is the "original" article, and not the second one; that said, I don't know if the revised schematics or PCB layouts (plus his notes) bear on the first article, or on the second:
http://www.markus.org/Electronics/Projects/AVR-Transistortester/
Finally, here's a long thread on the "porting" of the above tester to the Arduino, by pighixxx:
http://forum.arduino.cc/index.php?topic=164112.0
Based on what I could see, though, pighixxx has recently updated his site, and in the process broke all of his old links. You might try to get in contact with him, or with others in that thread to find the source code for that port, etc.
Personally, based on that thread's comments, I would do a another re-port of the system, as the original port seems to have gotten broken or something toward the end of that thread. It might be best to start over with the original design, and fix any problems as you find them.
Looks roughly the same but the one I have has a precision voltage reference. Looks close though! (Much closer than I got).
It is impressive what you can do with one Atmega328!
Anybody got a link to where I can buy one?
prjpte;w[;rjtk5yl;q.[#pjji
Rubbish post.. see below
Hi Henry_Best,
I got mine from Bang-good, I think it's US based but it all comes from China. I find mine really useful, think the smallest cap I can measure is about 28pF, good enought for most, the transistor part test all tranies, FETs and a few SCR/triacs, etc it even tells you what connection is what and where.
But as I said if we could get our hands on the original code, as I do think it needs a few changes!
Regards
Mel.
Mine measures 22pf without issue...
