USB-serial adapter COM# identifier

M

MPep

Senior Member
Hi chaps,

I am looking for software that is able to identify on your Windows system what COM ports are available.

Reason being is that every time you connect an adapter, and it is in a different USB port to what you originally used, will be assigned a different COM number.
e.g. you were using COM8, but when the adapter is re-inserted into another USB port, you could now be on COM9. Unfortunately, sometimes you have to search for it.

In case those of you that answer, why not look in Control Panel, System? Indeed, why not?
I would prefer for some software that can be run to tell you what is currently connected. As in an automated system.

Any ideas?

MPep.
 
I

inglewoodpete

Senior Member
MPep said:
Reason being is that every time you connect an adapter, and it is in a different USB port to what you originally used, will be assigned a different COM number.
e.g. you were using COM8, but when the adapter is re-inserted into another USB port, you could now be on COM9. Unfortunately, sometimes you have to search for it.
Click to expand...
If you are using a laptop, there are usually only 2 or 3 ports. Unless you fiddle with them, they will always open the same allocated COM port numbers. I've managed to remember them!
 
M

MPep

Senior Member
I understand what you're saying Inglewoodpete.
I have also seen a situation whereby the COM port number changed, even though the adapter hadn't changed USB socket! Weird. Will keep looking. :)
 
W

womai

Senior Member
At least for adapters based on the FTDI chip (e.g. FT232R) you can get the port info from the registry. I'm pretty sure other manufacturers (e.g. Cypress) make their entries there as well.
 
M

MPep

Senior Member
Correct, and what I would love to have is software that can read the appropriate parts in Windows and display that.
I am not a programmer by profession, although I love tinkering with PICAXE BASIC :D.
 
W

womai

Senior Member
What adapter are you using (which chipset)? If it is FTDI I should be able to put such a small tool together in less than an hour since I already know where to look in the registry. If it's the Rev-Ed USB download cable (which uses Cypress) I can have a look but it may take a bit to figure out where Cypress hides that info.
 
hippy

hippy

Technical Support
Staff member
The latest 5.2.9 Programming Editor has an option to automatically locate the AXE027 cable which will show which port it is on. Tick the "Check for USB Cable on startup" option under menu options, View -> Options -> Serial Port.

There's also a "Scan for USB cable" button on that same configuration screen.

The AXE027 uses the FTDI chipset, the USB010 uses the Prolific chipset. Information on USB ports is in a number of places within the Windows Registry and varies depending on Windows OS. It's a more complicated process to find the cables than just trawling the registry to determine which ports are assigned and which are connected.
 
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M

MPep

Senior Member
Thanks for the offer Womai.
In particular, I have no problems finding COM port numbers :). As most people of a technical nature shouldn't.
I am in particular, looking for software for clients who may not be technical enough to figure it out. This happens reasonably often, so began wondering.

I realise this is not particularly PICAXE related, but seeing as there is such a wealth of knowledge on this forum I thought I'd ask :D.

The main adapters I use are Prolific ones.
My main usage of these adapters is in connecting Iridium satphones to netbooks, and GPSs to nav computers.

Just for interest, a client of ours had purchased a notebook for updating his website via satphone as he was climbing Everest. He found that because of the lack of atmospheric pressure, his harddrive stopped working and subsequently crashed.
He has now purchased a netbook with solid-state harddrive. No more problems.
 
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