Another part question


 
D

DylanNC

TVWBB Member
Im getting ready to start putting my heatermeter together, reading the assembly instructions, the first resistor is 0 ohm if you use the recommended New Haven LCD display, if not the instructions say I should use the correct resistor for the display I am using. My question is I am using the Varitronix MDLS-20464B 20x4 anyone know which current limiting resistor is needed for this display.
 
I'm not sure, because the datasheet doesn't specify the forward voltage or current rating for the LED. You should be fine with just 0 ohms, because that's what I use on another project.
 
Bryan Mayland said:
I'm not sure, because the datasheet doesn't specify the forward voltage or current rating for the LED. You should be fine with just 0 ohms, because that's what I use on another project.
Click to expand...

I just built a HeaterMeter with the same 4x20 display. I installed a 0-ohm jumper and it's working fine.
 
Thanks, now the only thing I need to figure out is where to get a 16 pin ribbon cable to tie the display to the board. This project has been an adventure for someone with no previous electronic experience.
 
DylanNC said:
Thanks, now the only thing I need to figure out is where to get a 16 pin ribbon cable to tie the display to the board. This project has been an adventure for someone with no previous electronic experience.
Click to expand...

Originally I wired the display using a piece of ribbon cable. It turned out OK, I guess, except that I wired the display upside down (doh!). When I re-did the wiring, I could not find a local source of ribbon cable with 0.1" pitch, so I just went point-to-point. It's hackish/unprofessional, but it works.

Perhaps you can use a piece of ribbon with 32 conductors, and use every other wire? That might be closer to the right pitch.
 
It might help to know that only the left 6 pins and the right 6 pins are connected. D0-D3 aren't used.

I've also used a floppy drive cable to connect an LCD before, if you have one of those.
 
You must log in or register to reply here.

 

Back
Top