what usb -> serial adapter should i get?

[ChuckDickerson]

We have had no problems with the IOGear GUC232A.

[Astronouth7303]

If you want a real test of an adaptor, just hook it up to the dashboard, switch it to RC mode, and start reading data. Because the dashboard is set to the highest baud normally supported (115200), any USB adapter not able to handle it will bork.

Any adapter that handles this amount of data will be able to download code as rapidly as a native serially port. I'm not saying others won't, they'll just go slower.

[Dave Flowerday]

Originally Posted by Astronouth7303

If you want a real test of an adaptor, just hook it up to the dashboard, switch it to RC mode, and start reading data. Because the dashboard is set to the highest baud normally supported (115200), any USB adapter not able to handle it will bork.

The dashboard runs at 19200.

Any adapter that handles this amount of data will be able to download code as rapidly as a native serially port. I'm not saying others won't, they'll just go slower.

No, for a few reasons. First, like I mentioned above the dashboard does not run at 115200 so this test won't work. Second, and much more importantly, is that these USB->Serial adapters are fully capable of 115200 speeds - that's not the problem. The problem has to do with buffering built into the USB->Serial adapter and the nature of the USB protocol. These adapters buffer up data coming from the serial port and only transmit it to the PC at certain intervals, either when the buffer fills or when some sort of timeout expires. This adds lots of latency since the way the IFI downloader works is to send commands to the RC and then wait for a response. So, each response takes a while longer than it should, which slows down the overall transfer. This is probably also why some just plain don't work at all.

[Astronouth7303]

You know, a little voice inside said I should do my homework before posting...

As an addendum, my post was partly based on my own experience with a USB adapter. Downloading worked, but dashboard didn't. Don't remember what adapter or from whom. It was purple and had a USB B port (the square one).

[MikeDubreuil]

Originally Posted by RebAl

Parallax is based on the FT232RL

This is an incredible little chip by FTDI. We use them at work at their highest baud rate. We also run them for days at a time. They work great.

[Mike AA]

I have an interesting situation.

I bought a belkin usb to serial port cable and it could work for the dashboard but using the ifi loader would not detect the controller nor download data. I returned that and bought the radio shack version someone mentioned and its hooked up right this minute. Again the dashboard works fine but downloading and initializing /reading the controller doesn't work. I tried changing the buffer tried changing the speeds up and down to no effect.

Can someone please help me. I bought a new laptop and it doesn't have aserial port, which I knew when I bought it but I didn't think the usb to serial port converter would be this hard to get working. I would buy a pcmcia card to serial (which I did) but something I didn't realize the laptop doesn't have the slot, instead its an express card slot, which I can order a serial port for but they're $50+.

I would use my old laptop but the screen, harddrive and cd-rom are dying.

-Mike

[whytheheckme]

We are using a VEX USB-Serial cable on my MacBook Pro running Windows XP SP2 with no problems.

The VEX driver is even included in the easyC install (I think... If not, you can always use the CD it came with or download the driver.) This is really convenient.

Jacob

[BrianBSL]

Originally Posted by Mike AA

Can someone please help me. I bought a new laptop and it doesn't have aserial port, which I knew when I bought it but I didn't think the usb to serial port converter would be this hard to get working. I would buy a pcmcia card to serial (which I did) but something I didn't realize the laptop doesn't have the slot, instead its an express card slot, which I can order a serial port for but they're $50+.

I know some people who think the vex adapters work pretty well.

Also, don't even bother with the SIIG expresscard serial adapter. Its just a express card to usb adapter and usb to serial adapter in one card.

[Mike AA]

Originally Posted by whytheheckme

We are using a VEX USB-Serial cable on my MacBook Pro running Windows XP SP2 with no problems.

The VEX driver is even included in the easyC install (I think... If not, you can always use the CD it came with or download the driver.) This is really convenient.

Jacob

Would you be willing to post the driver? The stores in my area only sell the version which is just the cable which comes with a basic driver. Did you buy the RS # 276-2152 ? I am begining to think its no longer available?

-Mike

[jtdowney]

Originally Posted by DeepWater

We have had no problems with the IOGear GUC232A.

We've had good luck with this one as well

[Mike AA]

2 days ago I returned all the cables and adapters I bought and went to another computer store which had the IOGEAR. I bought the cable, brought it home and connected the cable to my computer and installed per instructions. With all the other cables I could get the dashboard to work but it wouldnt recognise the controller. So today I took my computer and the iogear cable and brought them to our 06 controller. Powered up the other robot hooked my cables together and to the controller. Started IFI loader, clicked on "Controller Verification" and voila the controller is recognised. I an 99% sure I got a bad controller.

So now I will go call IFI and see what I need to do to send in the bad controller and get a new one before we NEED it, I guess I'll use an old controller for programming...

-Mike