What UNO do I have

Development Tools IDE 1.x
1

I have 5 UNO boards that are not functioning properly. Three cannot access USB or at least the USB port doesn't show up when I plug them in. These three are different configuration than all the others I have. The have only one on-board led labeled "ON". The reset switch is small and rectangular.

The other two connect to ttyUSB0 no problems but will not upload any code and fail the loop back test. One gives an indication of no boatloader (on-board led does not flash when reset pressed)

So my question is what UNO boards do I have and is there any difference in the way they connect to USB ports.

I run Linux (Fedora 27) and have a few other UNOs that work just fine. This is not a big issue to me, but it is frustrating to have boards that for some reason just don't work. I suspect bad bootloaders, but loopback failure also has me concerned.

I will try to post some pictures later.

Here is a photo of both:

IMG_1222Scaled.png

IMG_1222Scaled.png

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Different USB-serial chips would be the the primary cause of differences in how the USB is handled.

It's hard to be sure from the picture, but it looks like both of those use the CH340 USB-serial chip (the rectangular IC behind the USB socket). On Windows we need to install the CH340 driver but it's my understanding that driver is pre-installed on Linux.

Check which USB-serial chip is on your working vs. non-working Unos to see if there's a pattern.

3

pert:
Different USB-serial chips would be the the primary cause of differences in how the USB is handled.

It's hard to be sure from the picture, but it looks like both of those use the CH340 USB-serial chip (the rectangular IC behind the USB socket). On Windows we need to install the CH340 driver but it's my understanding that driver is pre-installed on Linux.

Check which USB-serial chip is on your working vs. non-working Unos to see if there's a pattern.

Both are CH340G.