Hii all, i have UNO R3 board.
Issue : when connected to PC the board is getting powered on, but COM port is not showing/getting detected.
please help me how to figure out the issue.
- Because you're talking about a COM port I guess you're using Windows; please confirm.
- Did it ever work?
- Where is the board not detected? In the IDE or by the operating system (e.g. Windows device manager)?
- What is the serial-to-usb converter on the board? It's the IC closest to the USB port? If you don't know, post (a matter of drag and drop in a reply) a clear picture of the area around the USB port.
yes iam using the windows PC, i have another same board which is being detected & showing its COM port number.
in the device manager itself.
Can you please answer the questions 2 and 4?
Exactly the same board? Same serial-to-usb converter? Same cable used on both?
Unos use the big USB-B connector. Do yours as well? In case it's a micro-USB, make sure you're using a data/sync cable and not a charge-only cable.
Did you check the 'device manager'?
used the same cable for both
yes checked, but not showing the COM port
You still haven't answered point 2 in post #2. Did the problematic board ever work?
Although both are marked as Uno, they are not the same. A little bit of a wild guess but I think that the board in post #7 is the problematic one.
The board in post #6 has a CH340 serial-to-usb converter that is clearly marked as such.
That same IC on the board of post #7 does not seem to have markings. Can you confirm?
There also does not seem to be a marking on the 328P (IC in the center).
If there is no marking on the ICs, they are a more than likely a rejects / fakes; I would return it and ask for a refund.
Is there absolutely no reaction in Windows device manager? Or is there something with a yellow triangle?
yes you are right, we did not used it before, just opened the pacakge.
It looks to me, as though the crystal is missing/broken off, on the non-working Uno:
That would stop it being recognised by the PC.
Based on image post #12
The IC is marked as FT232 but has a 16 pin package. An FT232 has 28 or 32 pins.
In my view that IC is as fake as it can be, there might not even be a die in it.
yeah got it, can you please share the link of the crystal to buy and use here.
thank you sir, for figuring out.
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You need a 12MHz Crystal, such as this one.
It is in a low-profile package called 'HC-49S'.
You should use your favourite search engine to find a local supplier.
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If you have properly installed the FT232 driver software, perhaps the IC is damaged.
It seems that the problem only occurred with one of the two boards. @nama_venkata_swamy never actually specified which of the two was the problematic one. A reasonable assumption was made that it was the board with the CH340 chip and the missing crystal. If so, we don't have any indication that there was a problem with using the board with the strange "FT232-S16" chip. For this reason, I don't think the FTDI driver is relevant.
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