Raystar oled : Screen Issue - what I am doing wrong?

[lokki]

oh, the case is not grounded? that could very well be the issue then. let's hope it is as easy as adding a ground connection to the case.

[served]

For the bottom part. It would be possible to have Ground through the MIDI OUT connector.
With the TOP part. I will have to figure something out. The powderpaint is isolating everything.

[lokki]

well scratch that 

let's first see if this is indeed the issue.

[SoundRider]

Xavier's note : Aouch..... Sorry SoundRider i edited you message instead of replying 
Could only restore the following :

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May I ask a question ... can the screen error have a correlation to the use of the encoders? I had the screen issue only during twiddling the knobs. I had the PreenFM2 run for many hours - doing some burn-in like testing - never had the screen failure.

[Xavier]

May I ask a question ... can the screen error have a correlation to the use of the encoders? I had the screen issue only during twiddling the knobs. I had the PreenFM2 run for many hours - doing some burn-in like testing - never had the screen failure.

If you don't turn any knob, the display activity is limited to note on/off.
When you turn knobs, the display receive much more data to deal with. There's so more possibilities of a corrupted data.

For the reminder, only one corrupted data can turn the display in a broken state until you reboot.

[SoundRider]

I understand this, but why do I observe that the encoders move - but the values as well as the sound don't change as usual. The encoders require many more degrees of turning until a value changes ... if this makes any sense.

[Xavier]

I understand this, but why do I observe that the encoders move - but the values as well as the sound don't change as usual. The encoders require many more degrees of turning until a value changes ... if this makes any sense.

This happens under heavy load on all preenfm.
When the preenfm2 plays 8 voices of 6 op algo, there's not much CPU left for the display driver which refresh slower, and for the encoder driver which does not poll the encoder values fast enough.

The overclocked firmware has a slighty higher sample rate AND has a little more CPU left for display and encoder in heavy load situation.
If you don't use it aldready, give it a try.

[SoundRider]

Yep, I will check what OS I use ... could be the standard speed. Will give it a try ... thanks for your advice 

[tubeohm]

Hi ,  one thinhg, , i found here that  the Preen - powerd by USB  is not good .
I have on my USB power from the PC spikes and digital noise . This  so heavy that you hear it into the sound .
 This i had also by some clients. After changing from USP power to a separate Power supply  - all is OK .

So i switch the preen to a separate power supply. And the noise is away .
 I think this spikes can go also direct into the OLED and the result can be that  the OLED hangs .  It is a MAYBE - not a must 
 but i will test it on my next build and let you know .
Greets
 Andre'

[lokki]

the noise is to be expected with usb power from a pc i think. at least i know this problem from many usb powered devices. switching to a dedicated psu is always a good idea. the original problem seems to persist though even with a dedicated usb power supply, with no pc in the chain, so we can rule the pc out.

@soundrider: did you try with a 9v power supply? are there still display problems then?

[served]

I can say for sure. Its not psu related. I have tried with many psus. Even a linear transformer based regulated psu will have this issue.

[lokki]

sorry, yes you wrote that before...