ATmega 328P-U vs. ATmega 328P-PU with Arduino bootloader

I am a noob to the microelectronics world so if my question is stupid, please take into account my complete lack of reference for microelectronics and Arduino boards in particular.

I have two Arduino UNOs both of which I now believe to be clones. On one of the ATmega chips it says; "ATmega 328P-U," (a blue board with the small gold label "50th") and the other, an "ATmega 328P-PU" (green board with the Arduino sideways "eight") which I understood to have the Arduino bootloader.

Neither one of the clone boards has been completely successful in downloading the IDE on two separate computer software programs, Windows 10 and Mac OS - Mountain Lion.

Is it the clone board that are letting me down or is it me?

Those parts are the same, microchip just changed how they mark the DIP packages from PU to U.

The only thing that makes any difference about clone boards is which serial chip they have.

IIRC there's some sordid story about drivers on recent MacOS versions for boards with CH340G - like, there were a couple of OS updates which each required a new version of the drivers for the CH340G. I thought on latest OS couple of versions, that was sorted though. But that version is kind of old right?

delta288: Neither one of the clone boards has been completely successful in downloading the IDE on two separate computer software programs, Windows 10 and Mac OS - Mountain Lion.

I'm a n00b myself, but can you clarify the problem? From what you write it sounds like you cannot download the Arduino IDE (software you use to write the Sketches) software, but I'm guessing you are having problems with uploading the sketch to the Arduino clones?

What you can try is the following: 1. go into preferences and set the "Show verbose output during" to on for upload (you can choose between compile and upload). 2. Try to upload the sketch and see what error messages you get (you can post the error message here, which allows others to see if they can identify the problem). 3. Make sure the settings in the IDE are correct. - board = Arduino Uno - Port (depens on your computer, will be COMx for Windows and /dev/ttyACM0 or /dev/ttyUSB0 on Linux, I don't know the port that's used on a mac). - The programmer is set to AVRISPmkII but I don't know if this is required or only used for when programming a bootloader). - Make sure that there are no errors in your code (If you get an error message before the IDE tries to upload the code to the arduino there is most likely an error (typo?) in your program.

The C programming language is very strict and it can be hard for a beginner to find some of the beginner errors (for example when you type : instead of ;), but the IDE should report these errors (if that's the problem and the output is not helpfull you can try to set the compile error to verbose also, to get a more detailed error message, if possible reply with the code and the error message, and maybe someone can point out the problem).

To avoid the possibility of a typo in your code you can try to upload the blink sketch File -> Examples -> 0.1 Basics -> Blink to your Arduino and see if that works.

As I understand, since Arduino is Open Hardware the schematics are available and others are allowed to make "clone" devices that should be compatible with the "real" Arduino's (most have duino in their name or "Arduino Compatible" written on them).

As I understand the green-ish board with the infinity ("sideways 8") logo on it should be a "real" Arduino. Since that's a trademarked logo. It's possible that it has Arduino or Genuino written on it and both should be official Arduino's.

Hope this helps