LCD HELPZ VOTI 2x40 and SHARP LM40X21B

Testing/Troubleshooting
1

Hi EVRYONE,

first good news is that i have got the sidsynth up and running, making bleeps and responding to midi and also the SID control VST - thanks for the help with this.

Now i am stuck on the LCD,

i am currently trying the 2x40 LCD fro voti, afaik - all the pins are correct, during initial power on all the black bars light, then slowly they disapear and it goes blank. When i twist the contrast pot to adjust - it sometimes shows the black bars again - before disapearing quite rapidly. so i never get the black blocks for long, and i dont get any proper display - considering that my SIDsynth works great.

i also got the backlight working fine -

any ideas on what might be wrong - apart from the pins? might it be a particular pin assignment? or something different?

the other querry is the SHARP LM40X21B - its another 2x40 lcd in blue - i have searched all over the web looking for datasheets and found many, but none have the pin assignments - has anybody used this lcd or the normal yellow/green LM40X21? it has two rows of eight pins - ?

thanks for helpz

Digi

2

Hi Digi,

this could be a bad soldering on the power connections, you should especially check them - note: once the LCD got no power, it needs to be initialized again by MIOS (easiest method: power off/on the core), otherwise it will show the black bars like during the bootloader phase.

Best Regards, Thorsten.

3

I will tripple check the soldering and report back,

anyone got any ideas about the Sharp LCD pinouts?  ???

4

I don’t the pinout, but please don’t make too much experiments by swapping the pins, this can damage the LCD very quickly!

There is a LCD interconnection test application available at the MIOS download page, have you already tried it?

Best Regards, Thorsten.