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Propstick USB problems — Parallax Forums

Propstick USB problems

lmclarenlmclaren Posts: 104
edited 2011-10-13 19:00 in Propeller 1
Hi,

Are there any tricks to the propstick USB?

I have 2 of them, but neither want to play nicely.

I am using them on a breadboard to drive a vga display. I am using the VGAHiResTextGUI demo.

One of them will start and run about 1 in 5, sometimes it half starts with the video breaking up.
When it finally starts it seems stable.

The other just get hot :(

I have quadruple checked the power supply, I have the following connected.

Vin12, 5v reg
Vss 9 , gnd
Vss 10, gnd
Vss 29, gnd

P16- P27 to a Parallax VGA PS2 adapter.

I have nice short jumpers to the VGA, only 2.5cm.

I have tried putting bypass caps on the supply and even a pullup resistor to VDD on the reset pin.

No joy.

Comments

  • WBA ConsultingWBA Consulting Posts: 2,935
    edited 2011-09-30 22:25
    For the intermittent one, check the crystal socket. I had the same problem with my hydra and it was poor contact between the crystal's socket and the pins on the crystal. I bent the crystal legs outwards and that gave a bit more stable connection when I plugged it back in.

    Not sure about the one getting hot. Has it been used before or is it brand new?
  • lmclarenlmclaren Posts: 104
    edited 2011-09-30 22:33
    Both are brand new, I have tried reseating / tweaking the crystal, sometimes it helps it start but that might be my imagination.

    I am surprised that the regulator is warm only driving a vga adapter. I have checked the supply again, 5.29v with a Fluke DVM.
  • Duane C. JohnsonDuane C. Johnson Posts: 955
    edited 2011-10-01 06:49
    Is it possible that your hardware which is connected to the PropStick is operating on 5 volts or higher?

    Remember, even though the PropStick is powered from 5V the Propeller is itself running on 3.3V. Any signals from the external hardware could be driving the prop pins to voltages higher than 3.3V which can be fatal. Not good!

    Duane
  • lmclarenlmclaren Posts: 104
    edited 2011-10-01 16:32
    The only hardware connected is the VGA/PS2 adapter, basically resistors to the vga pins, 5v to the monitor and to run the kb. Used the same interface on protoboards without any problems.
  • lmclarenlmclaren Posts: 104
    edited 2011-10-02 14:17
    I have checked the VDD as well, 3.29v, all the power seems good, the only hardware is the video adapter.
    Of interest, I can get some of the video demos to run, my own project that has a vga display will not even boot. It seems very fussy re the type of display!
    I expect it is borderline unstable, not sure what else to check....

    Lee
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2011-10-02 22:30
    Is the problem with the Propeller itself or the video? That is, can you program/identify it consistently each time?
  • lmclarenlmclaren Posts: 104
    edited 2011-10-03 00:51
    One of the propsticks can be programed reliably, the other is not recognized.
    The one that can be programed seems to program fine, I programed it 5 times in a row to ram.
    When it boots to run the GUIDemo from the obex, it only shows a picture about 1 in 10, other times it is blank or broken up video. GUIDemo works 100% on my ProtoUSB.
    My own program which used a VGA display, never shows a picture on the propstick but is 100% on my ProtoUSB.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2011-10-03 13:15
    Is that the only object you're having problems with? What if you run another object that uses the same display? Also, you mentioned you programmed RAM 5 times, but what about programming to the EEPROM?
  • lmclarenlmclaren Posts: 104
    edited 2011-10-03 14:01
    Hi Chris,

    I have tried different objects, the GUIDemo and my own project which uses a different display object. GUIDemo is intermittent starting or breaking up, my own project which runs fine on the same monitor and kb wont even show a picture.

    I have programmed the eeprom and did not have a problem. I have even used it to run a serial only project but come to think of it, I was getting some freezes, hangs but at the time put it down to other problems.

    Seems like the osc is unstable...

    Lee
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2011-10-03 14:07
    Wel, you can try first swapping the crystals betwen the two units. Note what, if any changes there are.
  • lmclarenlmclaren Posts: 104
    edited 2011-10-03 14:10
    I will give it a try, wont be for 9 hours though... early morning here.
  • lmclarenlmclaren Posts: 104
    edited 2011-10-04 03:35
    I swapped the crystal from the propstickusb that gets hot into the one that is unstable, still has the same problems, sometimes I reset it 10 times and the monitor will not sync or the monitor flashes in and out of broken up picture. I have tried it on a different monitor as well, exactly the same. Sometimes it comes right and then it will be ok for say 5 resets.
    Even when the vga display is broken up, the program is running, I can see it updating the screen between flashes.

    My setup is, a propstickusb plugged into a bread board with the parallax vga/ps2 adapter connected via 1.5cm jumpers. I am feeding it 5v and the rails look ok.

    Not sure what else to check, can anyone else mock this up?

    regards

    Lee
  • lmclarenlmclaren Posts: 104
    edited 2011-10-04 15:42
    For some reason the propstickusb (i have?) is very sensitive to the video output, my program which uses a different vga display, wont even show a picture ever on the propstickusb but is 100% on a protoboard. I have tried .1uF across supply rails, disconnecting keyboards etc, The only thing connected is power, propstickusb and vga adaptor. I have even disconnected the usb, it makes no difference. Sometimes it will work and then I can restart the propstickusb 10 times in a row and it will be fine (with GUIDemo) , or it can go the other way. I have tried restarting the monitor and it does not make any difference, for some reason the video output is out of spec on (at least the one I have) propstickusb.

    regards

    Lee
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2011-10-05 10:05
    My best guess on this is that the timing (sync) of the video is right on the edge of what your monitor will sync to. It might be that the crystal on this one is slightly off, just enough to cause the issue on that particular monitor. I have a capture device that won't connect and capture from the Propeller using certain video objects because of timing. But others work. That is the only device I have that does that, but I did have a VGA monitor that didn't like the signal from a Propeller board and another monitor worked fine. In that case it was just a sync issue.
  • lmclarenlmclaren Posts: 104
    edited 2011-10-05 14:02
    Hi Chris,

    Its not just one video object that does not work, at least 2 different ones either are intermittent or simply don't go. I tested the exact same code on a quickstart on a veroboard to the vga adaptor and it works fine as well on all of the objects. For some reason, the 2 propstickusb's that I have are either faulty or very fussy. At the moment they are useless, they only seem to want to work for things that are not time sensitive. I have swapped the crystal so the problem does not seem to be that.

    Can I send the back to get them tested?

    regards

    Lee
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2011-10-05 16:43
    Lee,

    Before we have you send them back, is it possible to get a photo of the board/setup you have these on with the video interface? My concern is that the problem is intermittent. Typically if it was something on the Propeller chip it should either work or not on a timing sensitive application such as this. I would like to rule everything else out before having you ship them in.
  • lmclarenlmclaren Posts: 104
    edited 2011-10-05 17:17
    No problem Chris,

    I will do tonight, 8 hours away...
  • lmclarenlmclaren Posts: 104
    edited 2011-10-06 00:37
    Picture attached as requested, sorry for the size but I wanted you to be able to see the details.
    DSC03152.jpg
    1024 x 576 - 78K
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2011-10-06 17:03
    Ok, please call Tech Support tomorrow and we'll see what we can do.
  • lmclarenlmclaren Posts: 104
    edited 2011-10-06 17:09
    Thanks Chris,

    It is a bit hard for me to call with the time diff etc, is there an email contact I can use?

    best regards

    Lee
  • frank freedmanfrank freedman Posts: 1,983
    edited 2011-10-06 17:39
    Lee,

    1. Does the one getting warm do so all by itself with only the power supply attached? If so that stick would be a 99% probable failure (my opinion of course..)
    2. There was it seems to me a thread not far back regarding a failure of some of these to function properly due to missing ground connections between the QFN pkg Prop and the prop stick. Maybe aug. No way to tell w/o some way to fluoro (x-ray inspection) the board though......

    Frank

    FWIW I would have asked for an RA on the self heating one fairly quickly. Run the next one you get in through the pre-flight checks similar to those of the 40 pin PE-kit unit. Won't eliminate flakes, but will weed out DOA parts.
  • lmclarenlmclaren Posts: 104
    edited 2011-10-06 19:28
    Hi Frank,

    From memory it does, I will double check though.

    This problem is a bit unusual, I also have Quickstart and the protousb and both have been totally reliable and stable, running fine with all sorts of dodgy wiring. As soon as I try to do it neatly it turns to poop.

    The breadboard is the last step before I do a circuit board design, I was trying to simplify things and use the propstickusb for the prop and support chips and my own board for the custom circuitry.

    I take it that my experience is not typical, maybe a bad batch or just unlucky.

    regards

    Lee
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2011-10-13 12:04
    Lee,

    The E-Mail address for Tech Suport is support@parallax.com
  • lmclarenlmclaren Posts: 104
    edited 2011-10-13 19:00
    Hi Chris, we have already talked on the phone :smile:
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