Using USB with Serial Tower

[Mick]

From reading these forums I know that USB to serial converters seem to cause problems. But my laptop is more practical to use so it would be good if i can get round the problem.
The prob as I understand it is that the IR tower will shut down after 5 seconds causing download failures.
Has any body solved this still using the USB converter still using ver1.5RIS and still using the serial IR tower plugged into the converter..

Many thanks

Mick

[Ryan M.]

Are you saying you want to use a USB to serial converter to attach the serial tower to a USB port, or the USB tower to a serial port?

[Mick]

Originally Posted by Ryan Morehart

Are you saying you want to use a USB to serial converter to attach the serial tower to a USB port, or the USB tower to a serial port?

I want to use a USB to serial converter to attach the serial tower to a USB port.
Only short progs will download because the tower is switching off. This is how I understand it from reading other posts.
I just cant find any mention of a solution to this that does allow the use of the USB to serial converter with the serial IR tower.

cheers

Mick

[dez250]

(For those of you who are seeing this thread off the portal you may not notice that this person is asking about the IR programming tower for the rcx of lego mindstorms or for FLL.)

[CmptrGk]

why not just get the 2.0 upgrade disk from lego its only around $ 20

Originally Posted by Mick

From reading these forums I know that USB to serial converters seem to cause problems. But my laptop is more practical to use so it would be good if i can get round the problem.
The prob as I understand it is that the IR tower will shut down after 5 seconds causing download failures.
Has any body solved this still using the USB converter still using ver1.5RIS and still using the serial IR tower plugged into the converter..

Many thanks

Mick

[Mick]

Originally Posted by CmptrGk

why not just get the 2.0 upgrade disk from lego its only around $ 20

Well yes thats what I've done now although in the UK of course its a little more than $20

But it would be nice to understand the problem fully.
I surmise that normally the RTS pin on the serial port is kept high keeping the IR tower enabled and this is lost through the converter so it shuts down again.

I was just hoping that some one with electronics know how or programming skills would offer a simple solution.

But thanks for your replies...

regards

Mick

[Al Skierkiewicz]

Mick,
This is the first time I have heard of this problem. There are some various issues with both towers that have been discussed at great length in a variety of places. I did a search to see if I could gather any additional info for you but didn't really find anything important. As the RCX is a S L O W processor and USB is a pretty fast transfer, I suspect that the port is just running too fast for the port on the RCX to keep up. It is shutting down because it can't see the handshake from the RCX in time to wait before transferring the next chunk of data. You might want to try using the supplied software (for the USB convertor) to slow data rates down to a speed the RCX can keep up with.
I am assuming you have already gone through all the problems that might be interferring with communications at the IR level. i.e. IR emmiters like cameras security illuminators, remote controls and other towers can all interfere with communications. Sometimes a simple light proof box over the tower and RCX during programming does the trick.

[Mick]

Thanks for your reply...

Sounds quite possible that its something like that. I did try messing around with the settings of the USB converter but to no avail.
I've got my hands on the USB tower now which is after all the simple solution.
And this problem drifts off into the distance.

On with the building etc but part of me still wants to know WHY....!!

regards all

Mick.

[formatc1702]

hey!

just stumbled across this thread..
i was wondering whether NQC or similar stuff could be used together with the new usb tower (right now i have the serial one)
im having the exact same problem, a laptop without serial port

if it IS possible, i guess i'll buy this upgrade kit youre talking about

[Ryan M.]

I don't think you can. I'd guess that the problem isn't caused by the slow RCX (because the RCX isn't the factor which changes between USB and serial). It's probably actually the fact that serial/converter is slower than USB, so the program just sends the data too fast for the port to handle and it eventually just gets lost as whatever buffer it has gets too full.

[formatc1702]

hey!

now thats a quick reply!
one thing i forgot to mention: i also have an old vaio laptop WITH a serial port but it doesnt work either! i have no idea why, if anybody has a quick solution please post it!!! its a vaio pcg-fx776
for those who cant come up with a solution so far:
the fan for the processor of that pc doesnt seem to be working, it gets really hot if you leave it on.... there is no crashing or instability, but i think thats the reason why my sound card and my internal modem dont work anymore... they have completely disappeared from my device manager the serial port still appears, but the ir tower is not detected by the lego software... the config of the port (baud rate, parity, ...) is exactly the same as on a friend's pc where everything works fine (a compaq desktop) if anyone knows a solution here, i will be thankful too!

[Michael Hill]

BUMP