Usb to serial

taavi · Post by **taavi** » April 5th, 2008, 9:55 pm

Hi

I have an Anker Toplook 2x20 VFD display. I tested it on a pc and it worked well, but when I tried to use the display with a laptop it didn't work at all. I'm using a USB to serial cable because the laptop doesn't have a serial port so i'm guessing that's the problem.
Is the cable faulty or cant't they just be used with displays?

Post by **mattcro** » April 6th, 2008, 5:03 pm

It should work ok with a USB->serial adapter. There may be a problem with the adapter itself (faulty, or drivers not installed correctly) or the settings in Smartie. What do you have for the settings in Smartie? USB-Serial adapters often appear as COM6, COM8 or similar.

grantb3 · Post by **grantb3** » April 6th, 2008, 9:04 pm

The best USB to serial adapter's are made with the FTDI chip.

You can find out which serial port # to use be looking at the ports section of Device Manager.

taavi · Post by **taavi** » April 7th, 2008, 2:06 pm

COM is set to 1 and other parameters same as the PC-s, I'm using the crystal plugin because it worked on the PC, but when I start LCD Smartie it says:
Failed to open device: CRYSTAL.DLL Exception: The handle is invalid

The USB adapter is the cheapest HQ adapter I could find so should I try buying a new one?

Post by **mattcro** » April 7th, 2008, 9:09 pm

That error message sounds like Smartie can't find a serial port called COM1.
Are you sure that the USB-Serial adapter appears as COM1 on the laptop? It's likely to show up as a different numbered COM port.

As grantb3 said, you can check what COM port the adapter is in Device Manager (under Control Panel>System>Hardware, or Start>Run and type devmgmt.msc) and look in the Ports section. You should see an entry for something that has COM in the name. If there's nothing there, you probably don't have the adapter or its drivers installed properly.

taavi · Post by **taavi** » April 7th, 2008, 9:22 pm

COM was 4 originally, if I remember correct, I set it to 1 and it works because i've used the adapter to program a picaxe.

taavi · Post by **taavi** » April 7th, 2008, 9:43 pm

Reinstalled drivers, still nothing.

Post by **mattcro** » April 8th, 2008, 11:57 am

That error message is definitely because Smartie can't find that port. Check that the port really is running as COM1 (it might have changed back to COM4 or whatever), and that nothing else is using the port (programming software, another instance of Smartie...)

taavi · Post by **taavi** » April 8th, 2008, 1:59 pm

After reintalling the drivers that error doesn't appear anymore.
Checked adapter settings and all looks fine.
Tested the display on the PC again and it works there.
With the laptop the display still doesn't work.

taavi · Post by **taavi** » May 20th, 2008, 7:48 pm

Tried with a different serial adapter and got it working.