LDR Pre MkII - LDR volume control and I/O switching

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Joined 2007
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Set Paramters

Neb,

when I want to set the minimum resistance LDR values, it seems that it is not possible. When I in the menue go further down from Set Load Impedance, the screen goes black and I have to start again. Don't know how to proceed here.
Manual says, one should measure and put values in, except one gets a finished version. Can you guide here.


Cheers

Ernst
 
For those having problems reading component values, here's the image of silkscreen.
 

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Joined 2007
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You haven't fixed the problem. It should work without 1000uF capacitor. It seems that your oled has issues and injecting garbage into power line.

Do you think, this might be resoponsible not to be able to enter point 4 g (set parameters / LSE, LSH, RSE, RSH Minimum Resistance) in your user manual?

My display is just the one you linked to in your BOM.

Ernst
 
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Joined 2007
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Neb, wish you a fine Sunday!

First I checkted all the naked voltages with my scope. All three are ok.

Plugged in everything I have heavy signals on D+. After pulling out the display cable there is still some weird signal to see, yet it is much smaller. Then I soldered a 220µF cap directly to the display. The signal came down to 15mV and everything seems to work.

I flashed the Nano once again, and now I could go through the menue and set all things, including the LDR min resistance. I am now calibrating the thing again.

So I'm not sure, that the display is the reason, but I will order a new one. Do you accidently have a 1602 you do not need? I would be happy if you sold it to me.

Cheers, Ernst
 
Neb, wish you a fine Sunday!

First I checkted all the naked voltages with my scope. All three are ok.

Plugged in everything I have heavy signals on D+. After pulling out the display cable there is still some weird signal to see, yet it is much smaller. Then I soldered a 220µF cap directly to the display. The signal came down to 15mV and everything seems to work.

I flashed the Nano once again, and now I could go through the menue and set all things, including the LDR min resistance. I am now calibrating the thing again.

So I'm not sure, that the display is the reason, but I will order a new one. Do you accidently have a 1602 you do not need? I would be happy if you sold it to me.

Cheers, Ernst

I'm not sure display is defective. It might be like that by (bad) design. I had also few which were injecting noise into power line, so ideally, OLED should be on it's own power rail. Wide.hk are usually OK to replace it in case of malfunction.
 
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