LEDs suddenly working with half brightness.

  • hey,
    i decided to mount my monome in a angle of about 45 degrees, when i'm working with mlrv.
    first everything's fine but after a short time all the LEDs are losing their brightness and working with half brightness.
    what's the meaning of that? what's the reason?
    i hope this is no hardware problem.. is it a hardware problem? :D
    i'd feel relieved if you tell me this is a software problem...
    when it had happend, i closed mlrv, started up the monome-test and my gs64 was not in the device list...
    i've to disconnect it, reconnect it and then it works... but for how long?


  • are you using the most recent serialosc? this sounds like a software issue-- the serial data getting messed up. how many times has this happened?

  • hey tehn, thanks for responding! =)
    ok, I'm relieved for now ; ]

    it happened 2 times within 30 minutes, and yes i think i've got the most recent serialosc. i have my monome for 2 weeks now and installed everything the way how it is described in the "setup"-area..
    how can i find out whats wrong? how to fix it?

    is http://monome.org/community/discussion/comment/190630#Comment_190630 the latest and best serialosc or the one in the setup area?
    if galapagoose's is newer and better, do i have to remove things or stuff like that?
    i have the odd feeling that i have more stuff than i need on my computer, but i really don't know..

    please excuse me, i hope i don't bore you guys... this is all quite new for me! still have so much to learn..!
    besides i'm german which makes almost everything a bit more difficult : ]

    thanks once more!

  • To me that sounds like your device is loosing connection to the computer but still getting some power via USB. The USB protocol actually allows a device to draw only a limited amount of current from the computer. If the device is configured as a "high power device" and if it has a valid connection to the computer, the USB power supply will be enabled to support the full current.
    Your monome is such a "high power device" - meaning that it will draw up to 500mA of current from the computer to work. If for some reason the device is connected but not recognized as a "high power device" then the computer will limit the current that the device can draw to something like 90mA or so (this is done for safety reasons).

    To me it sounds like your monome is connected physically (thus getting some power to light the leds) but not connected on the software-side (thus getting only limited current and can't be seen in the devices list).

    I'm currently developing for the diy monome arc and i noticed the same behaviour for my prototype. Please take this as my guess - the problem might be somewhere else, but maybe my idea can hep you.


  • thanks for your thoughts!
    mh, this could be a possible reason as well...!
    but it happened just two times so far!? maybe it is/was really a software problem as tehn said...!? mhh....
    if the connection between monome and computer is too weak (hope i got you right),
    do you have an idea how to solve that possible problem?
    i'll definitly keep a weather eye on that!

    thanks once more =)

  • If my guess is right, I'd say it's a hardware issue. The only software thing that could prevent the device from beeing powered with the full scale current is the FTDI driver. I would not assume that this driver is faulty.

    Maybe the power supply that your computer uses to power the USB devices has lots of ripple or other noise, that eventually make the FTDI chip inside your monome reset itself due to bad supply voltage or something. This could breake the correct usb connection. It's just a guess - it's hard to tell without proper measurements of that power supply.

    Are you working with windows? If so, maybe you could go into the device manager when the device is working and look where the monome is listed there. Then after the fault appears, check back and see if it is still in the list. If not, we have a driver/hardware issue, where I would say the driver is probably okay and the hardware isn't.
    I don't know where you can check for connected devices on the mac, but I'm sure there is something like a device manager as well. The procedure would be the same there.

    Check these things and we'll see if my guess goes into the right direction.

  • damn, i just played for about 20minutes and suddenly all lights went OFF : (
    but the monome was and is still listed in the device manager!!!
    i can even continue working..... of course it makes no sense without LEDs..........

    yes, i'm working with windows 7 at the moment (but i'm about to get a macbookpro...)
    in fact all my 3 usb ports are in use (monome/audio interface/midi device). could this be the cause? my plugbar is full as well....?!

    i just want my monome to be safe!! could i cause a short circuit or something like that?
    please say something that makes me relieve ;D


  • Well, if the device is still listed in the device manager, then my guess is most likely wrong.

    I'm out of ideas now.

    tehn, I pass back to you at this point.

  • ok, but thank you very much for your thoughts once more =)

  • what's the make of your computer?

  • it's a:
    - Hewlett Packard "HP 625" laptop
    - AMD Athlon II P320 Dual-Core Processor 2.10 GHz
    - 4GB RAM
    - 32bit System
    - Windows 7

    at the moment i guess there could be too much cutoff-current, which disturbs the connection between monome and computer... i just have one electrical outlet in my room which is connected with 2 multi-outlet power strips which are supplying my computer, 2 monitor speakers, a mixer, 2 lamps, a turntable, microkorg and another mixer..... i think this is too much..

    i also realized, that my computer sometimes doesn't run correctly when i change electrical outlets, for example: i use my computer in my "studio", for my shows and sometimes in my bedroom... everytime i change the outlet "another kind" of electricity/power supplies my computer. maybe this leads to something like electrical confusion... it's good to remove the battery of the laptop and to press the power-button 3 times for 10 seconds to get out the cutoff-current.


  • maybe u just have a messed up battery. or call an electrician?

  • try an externally powered usb hub. that laptop sounds nightmarish.

  • thanks for the answer!
    i just bought an externally powered usb hub last week : )
    but still strange things are going on... please read:


    yeah, i'm about to get a mac book pro... i hope everything will work better with it...!
    "nightmarish" is probably a good description, which confirms me in buying a new laptop!

    thanks once more, tehn!

  • i guess this topic is solved, at least for me:

    i use an externallly powered usb hub and i'm working with a macbook.
    everything's perfect now!

    thanks for your help guys!