Com port problems

[mcmann01]

Hi All

Hope everyone is okay, Im looking for abit of assistance I have been passed the software and a ready made circuit for use with Picaxe. The cable which is connecting to my PC is a serial cable. When connected to my Com port and ran in conjuntion with the Picaxe software Im receiving error messages, basically saying that it is not connected at my Com port which it clearly is. Is their any fix's or poosible methods I could use to get this serial cable working with device and software. Just for extra information I have ran the same device with the USB version of the cable and it worked no problem with an successful outcome. Any suggestions are welcome and if any more information is required please let me know.

Thanks for your time and I look forward to your suggestions.

mcmann01

 

[hippy]

Welcome to the PICAXE forum.

As the USB cable works you are ahead of the game, everything else works and it should be a case of finding why the cable itself doesn't work.

First thing is to ensure you've selected the correct COM Port and check that the cable goes to the correct socket on your PC.

If that's correct then it sounds like a cable issue. Is this a Rev-Ed cable, home-built or obtained from somewhere else ? Does it have a 3.5mm jack plug end or a 3-pin molex ? Some pre-made serial leads to jack plug are not wired as the PICAXE requires them.

If you can answer that - plus whether using a desktop PC or a laptop - we can then suggest the best way forward to test the cable and connection.

 

[mcmann01]

I have it connected to the only COM port i have on the PC, but in device manager I have two Com ports setup 1 & 2. Picaxe only picks up com 2 ???

The cable has a 3.5mm jack plug end, and was purchased via the picaxe website. It is also connecting to a PC and not to a laptop.

Hope that this information helps us to progress.

Regards
mcmann01

 

[hippy]

With a Rev-Ed serial-to-jack cable (AXE025) there should be nothing wrong with the cable, and it should work just as well as the USB cable does (AXE027).

It is unusual for a PC to have only a single COM port fitted yet device manager recognises two. It could be there's an internal port which isn't wired up or is used for something else ( IrDA or similar ).

Check that you don't have anything in the System Tray or an application running which believes it is connected to a PDA, phone or modem. That could be holding COM1 in use if that's the one you need to use.

Do you have the PICAXE Programming Editor installed, or can you install it, as I believe that may have better serial port diagnostics than Logicator.

 

[mcmann01]

Sorry I must of been mistaken about the software, I'am using PICAXE Programming Editor, I will look for any devices in the system tray that maybe hogging the COM 1 port.

 

[mcmann01]

I found the culprit, it was Activsync which was taking the COM 1 port, but I have stumbled into another problem. Grrrrrrrr

When in Picaxe I load the options tab, then click on the Mode tab I then click on the "Check Firmware Version" button which results in

The Hardware connected to your computer:
Firmware version 4.3
(Picaxe-08 Firmware Version 3)

So from the drop down menu I select "Picaxe-08" which gives the information of the chip markings which is 12F629, and the chip does have this marking on it to confirm. Which is great

But when I try to run the program I get a very confusing error message which is:

Error incorrect hardware found for this software mode!

Possible Causes:
1 Software is in the wrong mode.
2 Wrong hardware connected

The software is currently in the mode for: Picaxe-08
The hardware connected to the computer is: Picaxe-20x2

Do you want to change mode now?

Yes or No.

Does this make any sense ? Please help

mcmann01
PS - it looks like were getting somewhere though

 

[hippy]

Gald you found the culprit and the cable itself appears to now be working (ish).

If running your PICAXE on batteries, try with fresh batteries.

Make sure you have the latest Programming Editor 5.2.9 installed, though I'm not sure this will resolve the issue in itself. Which version are you using ( Help -> About ) ?

Check with the USB, then serial, then USB cable again to verify it's not your target hardware which is a problem and is a serial cable only issue.

Then run the View -> Options -> Serial Port -> Test Port with USB cable and see with a meter what voltages you get on the physical Serial In download pin on the PICAXE-08 ( leg 2 ), then repeat with the serial cable after verifying Check Firmware Version still works and see how the two compare.

If we take it step-by-step we'll get there.

 

[mcmann01]

1) Batteries are working fine

2) Latest software installed

3) USB cable works fine no problems , serial problems.

4) When serial cable disconnected with LED flashing no measurements, when serial connected with LED flashing 0.75 Volts.

Hope this helps

regards
McMann01

 

[mcmann01]

Hi Hippy

Any ideas mate

Regards
mcmann01

 

[hippy]

Sorry I had missed your post #8.

If you're only reading 0.75V on the Serial In pin that could be indicative of the problem. The voltage on the pin should change from just above or below 0V to just below or above the power supply when the ' screen display LED' is on.

You say you have a 'ready made circuit'; is this something from Rev-Ed or something else ?

 

[mcmann01]

Hi Hippy

No worries about replying, the circuit I have in front of me is a REV-ED circuit, do you suggest getting another circuit from the Technology department were this one orginated from so I can test another? This is possible !

But it did work with the USB cable.

regards
mcmann01

 

[Technical]

If it works fine with the USB cable but not with the serial cable then something strange is going on with either 1) the physical serial cable or 2) the computer's serial port e.g. other software interfering with the port.