Error!, can't open port COM3

[harolds1956]

Hi, been writing programs and downloading using several chips and boards. Then I get the can't open COM3 port error message. Made no changes to the computer or settings. Just made a change to a program I was working on and tried to download. Tried rebooting, unplugging download cable, hard reset using several known good chips and boards. Still get the error message. Performed the serial cable test which came back "good". Any advice?

 

[Aries]

Assuming this is PE6 ...
Look at Settings. Check that COM3 is listed as an AXE027 port. If it is not, is the cable properly plugged in? And into the correct USB port? Did you do the cable check using PE6? If so, was it on COM3? Look at the port using Device Manager (under Settings) /Ports/AXE ports. Is COM3 listed as the AXE027 port? Check its settings are not corrupted (use PortSettings/Advanced). Also try putting the cable into another USB port - this should give you an alternative COM port to use.

 

[hippy]

When one has been using the PICAXE and cable and have successfully downloaded, and then it stops working, it is usually because the last program downloaded is causing the PICAXE to become busy and not see the next download initiation.

That is usually solved by a Hard Reset. When that doesn't work it is most likely the Hard Reset procedure timing is wrong rather than anything else. It can at first be tricky getting the Hard Reset timing right; too fast and the PC will have stopped trying to find the PICAXE by the time it is ready to see it, too slow and the PICAXE will have given up waiting to see if there is a download.

If using PE6 then there is help for getting the timing right. In the Workspace Explorer, usually at the top left, click on the "Compiler" tab at the bottom.

Turn the PICAXE power off. Wait a few seconds. Then click download. When the Workspace Explorer box shows "Connect power now! Searching for hardware on COMx" turn the power on.

That usually fixes things.

 

[harolds1956]

Fixed! Apparently with windows 7(which is what I am using) if you attach a device to a port that has "activity" it will automatically load a mouse or ballpoint(?) driver instead of the AXE033 cable driver. I had connected the usb end of the AXE033 cable to the computer while the other end was connected to a powered up picaxe, causing windows to think it was driving a mouse, and causing the error message. To fix all I had to do is:
1- unplug the AXE033 from computer and picaxe board.
2-power down the board.
3-plug in AXE033 to computer and board.
4-power up the board

Windows 7 then sees a "dead" device, assigns the AXE033 driver and all is well. Amazed that over all the years of working with picaxes (and windows 7) never had this happen!

 

[hippy]

Amazed that over all the years of working with picaxes (and windows 7) never had this happen!

Ah yes; that problem. It has been present since Windows XP and possibly earlier and does occasionally bite people.

It's a Windows issue, a legacy of handling serial mice even when it's a USB cable. It can happen with other USB serial interfaces as well as the AXE027, even with physical 9-way serial ports. It seems to happen when Windows sees serial data, status reports or DEBUG information on a port as it starts, assumes there must be a mouse or similar device connected.

There are options to prevent Windows presuming it has found a serial mouse or pointing device, and it shouldn't happen if the PICAXE is powered off or not connected when the PC is booted.

http://www.taltech.com/support/entry/windows_2000_nt_serial_mice_and_missing_com_port

What's a bit odd though is you got "cannot open port" errors but could do a cable test. I guess that doesn't really matter though now things are working and the problem identified.

 

[harolds1956]

Tried the registry change suggested and now works like a charm. Thanks so much!