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Auto reset problem

Posted: Sat May 24, 2008 11:57 pm
by mrkiss
Hi,

I had modified RBBB as auto reset version as in your manual.
But the auto reset doesn't work well. Sometimes it works but it's very rare case. Most of cases it doesn't work so I have to press reset button.

This is same on my two RBBB and my scratch build arduino RBBB clone. I burn the ada bootloader on your bootloader page to my scratch build clone.

I probed the RTS pin on FTDI cable and the voltage doesn't change when I click the upload button in Arduino on my PC. I think it should be changed to zero for a while but it doesn't change at all.

Is it Arduino IDE problem? or something?

Thanks,

Re: Auto reset problem

Posted: Sun May 25, 2008 11:44 am
by paul
You can't really see the reset pulse with a multimeter - it's too fast. You may just be able to see a flicker in between a fraction of volt. This is because multimeters have some circuitry (or physical configuration such as meter) that integrates (averages) the voltage over a time period, usually in the .1 - 1 sec. range.

In all likelihood this is your problem is you are using Windows. Set your serial port with the following settings:

Device Manager -> Com Ports -> USB Serial Port -> Port Settings -> Advanced button -> Set RTS On Close

This is necessary because the cable uses a different signal line than the Arduino boards. It works well though and is completely transparent once you set up the port settings. You don't have to do anything on Mac's, and I can't give you any advice for Linux although no real problems have been reported using the cables so I assume it's just a Windows problem.

Write back if this doesn't fix it.

Paul

Re: Auto reset problem

Posted: Mon May 26, 2008 6:38 am
by mrkiss
Thanks for your reply Paul,


But It sometimes works well.

Isn't it means all setting is right?

I think the setting is right, including 'Set RTS On Close' because it works sometimes.

Most proper working occurs on initial trying of single(?) task.

And I can't repeat it again. And after one or two weeks later suddenly it works well 'one time' and doesn't works

Only I experience this problem? Nobody there?


Thanks,

Re: Auto reset problem

Posted: Mon May 26, 2008 8:45 pm
by paul
This is the exact symptom of the problem. It will download one time only after reseting the serial port (probably requires a reboot).

Please change the appropriate serial port settings and your problems will be over.

Paul

Re: Auto reset problem

Posted: Mon May 26, 2008 10:34 pm
by mrkiss
Maybe you think I didn't set it and argue. But I did already 'Set RTS On Close' on from the time when I start Arduino :)

And checked it just before write this reply.

By today's checking, I saw auto reset works one time per one boot of my PC, like you said.

But it doesn't related to 'Set RTS On Close' setting in my PC. Auto reset works one time per boot no matter what the setting is.

I tested it several times on both cases.

Maybe my PC is crazy? or Maybe is there any other setting in windows? :?:

Thanks,

Re: Auto reset problem

Posted: Wed May 28, 2008 4:21 pm
by paul
It's really hard for me to say what the problem is since this is a scratch built board, and not one of mine.

If the it works with a manual reset, I would say that the problem may be in the reset system.
Are you using a 10k pullup resistor? And a .1 ufd (104) coupling capacitor to the RTS line? Without the cap, it's not going to autoreset.

Beyond that - you could try the Diecimila bootloader and see if that works with your setup. Do you have a .1 ufd decoupling cap across the power rails?

Put an resistor and LED on pin 13 - you should be able to see the chip reset there if you are successful.

That's what comes to mind. Good luck

Paul

Re: Auto reset problem

Posted: Wed May 28, 2008 8:55 pm
by mrkiss
Two of my RBBBs are bought from you not scratch built. I had scratch built another one

So I'm using 104 cap on RTS and there is no .1 ufd decoupling cap across the power rails.

And I put the LED on pin 13 so, I can see when it works

Is it possible the decoupling cap might solve this problem?

here is the pic of my RBBB

http://www.flickr.com/photos/mrkiss89/2 ... 4177271081

Thanks,

Re: Auto reset problem

Posted: Thu May 29, 2008 12:03 pm
by paul
Well I'm stumped. If it consistently resets after reboot then it seems like you must have the capacitor in correctly. From there my only guess is that it's something with the way Windows handles the serial port. Setting the "set RTS on close" checkbox has cured all the other cases of this I've come across, including Vista. Make sure you're setting the proper port that is associated with the cable.

Send in your OS specs so others will have a clue and maybe someone will come up with an answer, or the problem will repeat itself.

I don't seem to have a flickr account - I thought I signed up for one, and don't have time to sign up now. Check the RBBB instructions for the original board, to make sure you got the cap right, but as I said before, it sounds like you have it in right but software is not generating the signal.

Write back if you get to the bottom of this, I'm really curious.

Paul

Re: Auto reset problem

Posted: Tue Jun 03, 2008 9:08 am
by dogbert
Paul,

I have the same problem .... Auto reset works once. I can unplug the USB cable and re-insert it and again it will work once.
I am using windows XP pro. I also see the same type problem on a serial board. IMHO it has some thing to do with the serial driver's handling RTS. The Diecimila schematic has two paths, one cap on RTS and one on DTR. Do Diecimila users ever see the problem?

Dave

Re: Auto reset problem

Posted: Tue Jun 03, 2008 12:00 pm
by paul
The Diecimila schematic has two paths, one cap on RTS and one on DTR. Do Diecimila users ever see the problem?
The Diecimila uses the DTR line for reset signalling I believe, most of the time though the RTS line will parallel the DTR line, except when it doesn't I guess.

I suggested to the Arduino team that they consider the RTS line instead but maybe the boards had already been laid out when they told everyone else. Conspiracy theory advocates could of course believe they picked that line because it wasn't available on the cable. Maybe the Arduino team had some previous info in these arcane Windows serial port issues, that we're fighting with right now.

Dogbert can you please report your OS and machine details so we can try draw any possible conclusions about machines and serial ports that have these issues. I wonder if the FTDI drivers have anything to do with this.

I have a generic PC with XP home ed on it that seems to work fine. I definitely have to change the RTS setting though. Maybe try updating the FTDI drivers to latest version and see if that helps. Also FTDI support is worth a try, they usually get back to you in two to four days.

Ask them if the DTR and RTS lines are paralleled in their driver. My guess is that it's a Windows issue though, since the RTS checkbox cures things.

Paul

Re: Auto reset problem

Posted: Wed Jun 04, 2008 12:23 am
by mrkiss
I use windows XP pro version 2002 service pack 2 in Dell Demension 5100 model and Arduino 0011Alpha

And I tell you about the event after last post.

Suddenly two RBBB(that I bought from you)'s auto reset worked well but I didn't change anything about them. and my scratch build RBBB clone still didn't work. and all it was for only about a day

Today I tested them again, they works when they want to do. I can't find any rule from their behavior :?:

Even 'the one working after booting' is not the truth anymore. They doesn't or does work after PC booting

Re: Auto reset problem

Posted: Thu Jun 05, 2008 7:22 pm
by paul
Users should also check this link in my forum, which is also pointing to the auto-reset issues with the DTR line, and potential fixes. Hopefully David Mellis will be forthcoming in tracking this down, and getting the fix into core. If not I'll just have to post patched copy of the Arduino IDE on my site.


http://moderndevice.com/phpBB3/viewtopic.php?f=15&t=14
http://www.arduino.cc/cgi-bin/yabb2/YaB ... 363121/0#2
http://www.ladyada.net/forums/viewtopic.php?t=4703

Re: Auto reset problem

Posted: Thu Jun 05, 2008 7:35 pm
by paul
OK, the plot thickens in regards to the auto-reset problem. This concerns Linux users, but I'll bet something similar must be going on in certain versions of windows, and the "set RTS on close" is just a correction for the way Arduino IDE handles the serial port (vis a vis DTR / RTS lines).

As I said in the other post, if I can't get Mellis to fix the Arduino IDE, I'll try and get a patched version to put up on my site.

http://moderndevice.com/phpBB3/viewtopic.php?f=15&t=14
http://www.arduino.cc/cgi-bin/yabb2/YaB ... 363121/0#3
http://www.ladyada.net/forums/viewtopic.php?t=4703

Re: Auto reset problem

Posted: Tue Oct 21, 2008 4:41 am
by mrkiss
At last I got the solution

I changed the capacitor into 1n from 100n. It works both on my RBBB that I bought from Moderndevice and my scratch build arduino clone

What is the purpose of the capacitor connected to the reset switch?

Is This solution safe? My solution works but I'm afraid of its side effect :-)

Re: Auto reset problem

Posted: Thu Oct 23, 2008 5:59 pm
by paul
It's supposed to be 100 nanofarad. (.1 ufd - 104) Don't my instructions show that.
The idea with the series capacitor is to allow a low going pulse on the DTR line to reset the uC but still have the pullup resistor holding the reset line high so manual reset will work too. It also allows more flexibilty in the way DTR / RTS lines are wired so that a couple of different lines could provide the reset pulse.

I would expect that the smaller cap would be flaky in exactly the way you describe. It doesn't pull the line low enough for long enough to be effective.

You have the right one in now - if you understand the difference between nanofarad and microfarad. Even if you don't, don't worry about a bigger cap, it isn't going to hurt anything.

Paul

Re: Auto reset problem

Posted: Sat Dec 27, 2008 12:40 am
by schamberlin
I just wanted to add that I was having the same problem with my BBB: auto-reset would work once, and not again.

Device Manager -> Com Ports -> USB Serial Port -> Port Settings -> Advanced button -> Set RTS On Close

fixed it for me, now it works like a champ.

Re: Auto reset problem

Posted: Tue May 05, 2009 10:02 pm
by rainbow2009
pret auto
Thanks for the feedback. That is very useful. ;)
Regards,

Re: Auto reset problem

Posted: Tue May 19, 2009 5:04 am
by sontom115
That's pretty good. :lol:


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Re: Auto reset problem

Posted: Mon May 25, 2009 1:55 am
by ranmori
Thanks, it's a great tip, i used it already, and my plan is running smooth now :)
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Re: Auto reset problem

Posted: Fri Jun 12, 2009 2:25 am
by bobtom115
Thank you, this is good news for other visitors :lol:

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