preenfm Forum

PreenFM => preenfm2 and preenfm3 => Topic started by: sound30 on January 25, 2017, 02:22:03 PM

Title: [Resolved] LCD display not working
Post by: sound30 on January 25, 2017, 02:22:03 PM

Hi,
I soldered my Preenfm2 kit, which i bought directly from the preenfm-shop.
Unfortunately the LCD-screen ist only showing background lightning and no characters when powering over usb. The 3 leds are flashing before and I have also access to the usb-stick with the pfm2-folder.
Any idea what is wrong here?

Here are some photos of the build:
https://drive.google.com/open?id=0B2LA-oD6Z2H0a0swTTM3X19KNDA

Cheers

Title: Re: LCD display not working
Post by: mmontag on January 26, 2017, 11:55:52 AM

I think you need to add a wire across the oled resistor spot in upper right corner to complete the circuit.

Title: Re: LCD display not working
Post by: sound30 on January 26, 2017, 12:37:47 PM

Do you mean this connection (see picture) even if I have a LCD display?
https://goo.gl/photos/ZvdfFiMXaNLpem6p8

Thanks for the quick answer  :)

Title: Re: LCD display not working
Post by: Xavier on January 26, 2017, 01:33:11 PM

Yes it needs to be wire.

Quote from: http://ixox.fr/preenfm2/build-it/thebuild/

If you have a PCB revision R5d, you’ll have an additional resistor named Oled on the right of the above picture .
Populate it with a 22 ohm if you have an OLED display or shortcut it with a resistor pin if you have a LCD display.

Let us know when it's working :)

Title: Re: LCD display not working
Post by: sound30 on January 27, 2017, 10:08:48 AM

I used one wire of the 22 ohm resistor which was included in the kit (needed for oled but not for lcd displays) to short the two points.

https://goo.gl/photos/nVkjHKsSvyuWxEEk6

And now it works :)

https://goo.gl/photos/UnKGCoZ2dnsocNEN8

Thanks guys for the quick help   :-*

Title: Re: LCD display not working
Post by: Xavier on January 29, 2017, 02:19:03 PM

Quote from: sound30 on January 27, 2017, 10:08:48 AM

And now it works :)
Thanks guys for the quick help   :-*

Nice ! Thanks for the update  :)
Don't forget you can adjust the LCD contrast with the variable resistor...