Howdy,
I’m really having fun with the SparkFun Inventors Kit, however, I have tried to read the Arduino schematic, I really can’t tell what many of the parts on it are. Is there any place where I can find a drawing or pictures of what they all are? Things have really changed since I took a home study electronics course back in 1977.
Thank you for your help,
Old Sub Sailor
Does this help?
Thank you for the help. The link sort of helps, however, it shows a schematic (blurry on my iPhone), provides a listing of the parts (and links to help find out about them… to some degree), but alas there is still no identification of the parts as they sit on the board.
Ask about specific parts and then someone can help.
If I knew what they were . . ., ;^)
However, here is where there is a good start at what I am asking about. This may be the only site that does it:
http://www.ladyada.net/library/arduino/unofaq.html
Perhaps I need to ask the Good Lady for more pictures, eh?
That same site also has the PCB layout. Along with the list of components, you should be able to get there (though viewing it on an iPhone may be part of the problem.)
Alternatively, get a copy of Eagle (there’s a free version that should do just fine) and load the Eagle files as offered by Arduino or from the SparkFun pages, for example. That allows you to get a closer look at component placement, which part in the schematic is which part on the board, etc.
I’d be happy to help, but knowing exactly which Uno you’re talking about (original vs R3, atmel microcontroller in DIP package vs SMD package, etc) would be the first step.
Hi Kamiquasi!!
It’s the SMD package that SparkFun is sending out now. There was no such critter, SMD, when I took my home study course in the mid 70s. Heck, DIPs were something like black magic; the guys that I was working with at the time, old Navy Nuke ETs had not even learned about transistors, they used something called mag amps (all of us were in Operations at a nuke plant). I had been a Nuke MM, so it was a major change on the learning curve for me then, and heck it’s gotten even steeper now, and much harder on my 65 year old eyes to boot. I have to print out the sketches to be able to read them. That light grey that the IDE uses for comments is murder for me to read.
I appreciate the feedback.
OSS
Hello OSS 
I’ll just get the comments thing out of the way first; newer versions of the Arduino IDE require you to edit a Theme file. There’s several pre-made themes out there, but you could start with just adjusting the existing one to your liking… especially if the comments are not very clear. See the following external forum thread for more information:
http://arduino.cc/forum/index.php/topic,44202.0.html
Now then, the board. The Arduino UNO R3 SMD edition - https://www.sparkfun.com/products/11224
If you have Eagle - or don’t mind downloading the free version ( http://www.cadsoftusa.com/download-eagle/ ) - read this section. Otherwise, skip way ahead.
I couldn’t find Eagle files for this board. I’m sure there have to be some, somewhere, but at some point trying to hunt things down on the internet when there’s an alternative at hand just becomes horribly unproductive. The description states that the SMD board is essentially the same as the DIP board, just with an SMD version of the Atmel microcontroller on there. That’s easily checked if you open up the DIP version of the board ( http://arduino.cc/en/uploads/Main/ardui … -02-TH.zip ) in Eagle (open the .brd file, it’ll ask you if you want to open the .sch Schematic file as well), and the photo of the board ( https://dlnmh9ip6v2uc.cloudfront.net/im … 24-05c.jpg ) side by side (rotate the photo 90 degrees counterclockwise). The board can be a bit cluttered, so let’s get rid of a few things and only look at what we’re interested in.
In Eagle, where the blinking cursor is, enter the following two commands:
ripup *
display none top pads torigins tplace tvalues Dimension
The first line gets rid of all traces on the board, but keeps the SMD pads (Eagle doesn’t differentiate the two). The second line hides all the layers we don’t want to see, and shows the ones we do.
The board photo and the display in Eagle should look something like this side-by-side.
http://i.imgur.com/kX3fe.pngOkay, so that does look pretty much like somebody took the Arduino reference board and just replaced the DIP package microcontroller with an SMD one. It looks a bit silly the way it is, but it works. So now we can go about finding more information on each part.
Click on the info button in the top left of Eagle (looks like a big ‘i’, you can also enter the command ‘info’), and click on something that looks like a part. Let’s pick that suspicious looking red square with all the tiny pads around it:
So now we know that it is U3, which wasn’t clear before, and it’s a part with a value ATMEGA16U2-MU(R). So let’s find out what the ATMEGA16U2 is supposed to be on there. If you google around for ‘arduino uno atmega16u2’ you should quickly find that it is actually described on the official Arduino Uno page ( http://arduino.cc/en/Main/ArduinoBoardUno ). It states:
So basically, it's another microprocessor that they're using to translate the USB signals to serial signals that the main microprocessor can then work with, and back the other way when you need to read something out over USB.The Uno differs from all preceding boards in that it does not use the FTDI USB-to-serial driver chip. Instead, it features the Atmega16U2 (Atmega8U2 up to version R2) programmed as a USB-to-serial converter.
The Adafruit site explains this in much more detail.
Let’s try another one. That odd set of 8 pads with “10K” next to it, for example. You’re probably familiar with 10K in the context of a 10KOhm resistor, but those only have 2 legs.
Well, the name - RN1 - seems to suggest a resistor… R, but what’s up with that N?
The value is of no use here, but right at the bottom is something that is “BOURNS Chip Resistor Array”. Ah, so it’s basically several resistors in 1 package. In fact, that’s what the N stands for - Network.
You can do the same thing in the schematic. You might be familiar with the op-amp symbols in the top left of the schematic, for example, but have no idea where those are on the board. Again, use the ‘info’ tool, and now click on one of the op-amps in the schematic. It will show you the information (some manner of LMV358 (which can be seen in the schematic and board as well) - Dual, General Purpose, Low Voltage, Rail-to-rail output op-amp device) but it will also highlight the part that it is in on the board:
http://i.imgur.com/xbipy.pngOkay, actually, that’s not nearly as clear as one would hope. You can make the colors of each layer more clear, or choose a different color scheme (much like the Arduino IDE troubles). There’s another trick, though. Remember the part name (U5), and go back to the board window. Now type the following command:
show @ u5
The @ makes it draw a line out from the top-left corner to the part, which itself is indicated with a big rectangle.
( Note: sometimes, such as in the above, the rectangle is rather big due to associated text that’s being displayed, which can be misleading. )
So if somebody ever refers to R2 and you’re scrambling to find R2 on the board, just use ‘show r2’ or ‘show @ r2’ and you’ll have it in no time.
( Type the command ‘show’ to hide that indicator again. )
You can do this with pretty much every part and easily discern how the schematic’s components are placed on the board, and what they are. If you make a print-out, you can just use some pen & paper to scribble notes, and end up with something like this:
[
Full size: http://i.imgur.com/HIFKK.png
Except, hopefully, a lot more informative A lot of the information on what each component does, exactly, is out there - but it can be some digging around.
I hope this gets you on the right path to finding what you need. We’re a helpful bunch, though, so always feel free to ask :)](Imgur: The magic of the Internet)
Yeah, but the Atmega16U2 exists in the non SMD Uno as well.
OSS, if you could draw circles around which parts you are interested to know about, and post the image, we can help you out.
That last image Kamiquasi posted, I’d say is the most informative.
