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firmware re-flashing required every few days to keep LXR alive

TSRTSR
edited November 2013 in Troubleshooting
Every few days, my LXR acts weird after start-up. These are some the symptoms:
- sometimes the screen shows two complete rows of full blocks, sometimes crazy characters
- play-button does not react, or only when pressed a few times
- mode select does not work properly

Simply, the machine is not usable in this state. After firmware re-flashing, the LXR acts "normally".

I am running 0.24a with a small custom sample set (< 480 kb).

Comments

  • rudeogrudeog
    Have you tried using the stock 0.24a firmware? (not the one that lets you load samples)
  • TSRTSR
    I have been running 0.24a only a few times before switching to the beta firmware with user sample loading. Did not test all functions of the LXR, but I cannot remember that I had to re-flash the unit.

    Probably, I will "downgrade" to the non-user-sample version and see what happens.
  • TSRTSR
    edited November 2013
    Updated to standard 0.24a.

    This what a first boot brought up! - See picture.

    Re-flashing does not remedy the problem.
  • TSRTSR
    Unzipped the SD card image and flashed firmware 0.21. LXR runs.

    Trying to update to 0.24a now tells me "header error". Repeated several times with two different SD cards. No difference.
  • julianjulian
    Header error means it found a file named "FIRMWARE.BIN" on the SD card and could initialize the SD card correctly. The .bin file has a signature in its header that is checked to see if it is a valid image.
    So it seems the firmware image on the SD card is corrupted.

    the image should be around 240kb and if you open it with a text editor the first 4 letters should read "SPFI"

    is it only the front panel that is acting strange after a few days? or is the sound engine acting strangely, too?
    So when the problem occurs, is there still something playing if you manage to press the start button?


  • TSRTSR
    edited November 2013
    The 0.24a FIRMWARE.BIN on the SD can be opened with a text editor and shows SPFI as initial letters. The size is approximately 249 kb.

    I re-copied the 0.24a (non user sample) file to SD, still it showed the same size and could be opened with a text editor. Then I was able to update the LXR.

    However this is the result after boot of the "success!"-message. See pic. It does not respond to any button pressing at all.

    At the moment, I am not able to answer your other question since I cannot remember precisely and my LXR is currently not operatable - so that I could check again.
  • julianjulian
    could you have a look at the sd card socket pins on the mainboard? maybe one of them is loose and garbage data is read from the sd card. also check the soldering around the 4050 IC (it handles the communication with the sd card.
  • fcd72fcd72
    I feel some 40xx50 type hassle coming up....
  • TSRTSR
    edited November 2013
    Reassembled the LXR housing, checked the SD card pins and the 4050 IC for seating/solder points. All fine.

    Forgive my ignorance, here is the complete story of this mess-up:

    - built my own "LXR 1"
    - took a brand-new Sandisk SD card for installation of 0.24a, did not format it, did not check file system
    - "LXR 1" was running
    - built a second "LXR 2" for my friend
    - donated him my SD card, also installed 0.24a on his machine
    - "LXR 2" was running
    - used another brand-new SD card with own "LXR 1", same type and probably same batch, did not format it, did not check the file system
    - installed 0.24a with user samples --> strange behavior occured, had to re-flash the firmware after a few days to keep the machine alive (this has to be validated again!)
    - downgraded by copying the original sd card image to SD card and installed firmware 0.21
    - "LXR 1" runs 0.21
    - tried to re-install 0.24a (with or without sample user set), delivered messed up screen - see my former comments

    Summary
    As it looks - my fault: The SD card file system was FAT, instead of required FAT 32.

    Questions that remain:
    1) Why did the FAT SD card and installation work the first few times with 0.24a and 0.24a (user samples) on my "LXR1"?
    2) Why did it not work later on?
    3) Why did installing 0.21 (SD card image) always work with FAT?
    4) Why did the FAT card work to install the firmware 0.24a (user sample) on my friend's "LXR 2"?

    By the way, I am a Linux newbie and used Linux to copy the firmware to the SD card. In the last successful trial, I used XP to format the SD card to FAT 32 and also copied the files under XP.
  • untoldlbuntoldlb
    edited November 2013
    really weird, after several weeks using my LXR without any problem, yesterday it was impossible to select an other voice than BD1, reboot after reboot I still have the same issue, one time the sound get totally fucked up, then my display showed weird characters and letters. flashing the firmware solved the problem, but it remains a very strange behavior.

    firmware 0.24a

    as TSR I'm using a set of samples with this firmware

    thx
  • tixivtixiv

    This Problem could be due to the brownout detector on the AVR not being enabled. I had the same Problem with two of my own AVR projects, that used a bootloader and didn't have the BOD enabled. Enabling the BOD solved the problem.

    Sadly, this can not be done using the bootloader, but it is possible using an ISP adapter, like for example the USBASP. They can be ordered on ebay for 3 Euros from China.

  • voidvoid

    Sadly, this can not be done using the bootloader, but it is possible using an ISP adapter, like for example the USBASP. They can be ordered on ebay for 3 Euros from China.

    Is this the sort of thing you mean -

    image


    If so, i shall buy one.  My LXR is also having issues, similar to above.
  • vasculatorvasculator
    edited November 2013
    i actually just had to flash my firmware again to fix an issue.  snare1 and clap/cym starting having only 2 rows of FRQ parameters in the OSC and AEG sections.  changing one param value changed them all at the same time and the respective parts didn't respond at all to those changes.  reflashing the firmware fixed it.
  • julianjulian
    I will enable the BOD on any AVRs being sendout in the future.
    I must admit I never build and usedan AVR projectwith a bootloader before :-.

    The pictured USBASP works great (just a little bit slow)
    I got one from here
    https://guloshop.de/shop/Mikrocontroller-Programmierung/guloprog-der-Programmer-von-guloshop-de::70.html

    but they can also be found from china on ebay and amazon.

    never had any problems with the various prototype and finished units here though!
  • nilspupilsnilspupils
    One temporary solution *might* be plugging and unplugging the LXR (to turn on or off) only when the supply is already on and running and *not* by switching the power supply on and off. Some supplies might not turn off in a controlled way and put the AVR in an uncontrolled state by that...
  • julianjulian
    It might be.
    Most of the time i just plug the PSU jackin and outonmy units.

    It never occured to me that the bootloader could be affected by a brownout.
    I alwaysthought this ismoreintended for control applications, where a faulty controller uC command could cause hardware damage (think switching PSU,robot...)

    If anyone of you that has theproblem triesout the alternative fuse settings, please report bak if it solved the issues. It is always hard to say something about a bug that won't happen onmy units :-/
  • xoxerxoxer
    Hi,

    I don't know if it is the same problem, but the following happened with my LXR:
    1. Built with no problems, all works fine since the last 6 weeks.
    2. Yesterday I powered up all my equipment. The LXR shows the same picture as TSR's machine did. No LEDs lit up, no operation possible. Just wired blinking and changing symbols.
    3. A lot of messing around with different PSU and sd card fomatting.
    4. Solution: I forgot to boot from sd card (pressing the rotary encoder while switching on). After booting, everything is still fine. This happened the first time. I don't have the actual firmware installed. I know I should. Because I have the same problem with MIDI syncing like others have. When the LXR is master, after a few seconds the rest of my equipment stops playing, LXR is still running. After 10 Minutes it works better and the sync gets lost only sometimes.

    Any idea? The whole equipment stuff is powered up by one main switch. Is it possible that the AVR don't like peak voltages when powering up together with other stuff?
  • julianjulian
    Is anyone of you who is experiencing this problems able to get his hands on an AVR programmer to try the different fuse settings? I'm reluctant to send out new AVRs to all of you until I'm sure this is what's causing the trouble.

  • vasculatorvasculator
    I have not run into the issue again since I started plugging the PSU jack while the PSU is already powered.
  • rudeogrudeog
    After having an issue with my unit today which looked similar (was powering up and down the unit quite a bit using a switch I added it suddenly died, and only came back after I reflashed the firmware). So I read back through this thread. If I can reproduce it reliably, I'll try hook up the old AVR-ISP and turn on the BOD fuse and then see if it doesn't happen anymore.
  • xoxerxoxer
    Hi Julian, no need to send me a new AVR. It was the first time my LXR seems to be that it lost its "brain".
    Since then everythings is fine.
    just one thing to mention: Individuial 3 and 4 have a annoying hum (can't say how much db, but you can hear it when no basdrum is playing). Output 1 and 2 are fine, so it should have nothing to do with my power supply or with some sort of ground looping.

    I have not tried a "simple wiring" (only lxr to amplifier). Maybe this should be a new thread  - sorry.
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