I can't get these modules to make any light at all (not even a flicker or a pixel).
Larger: LOD-H02004DP-G
Smaller: LOD-H01602DP/A-Y
![](https://www.eevblog.com/forum/beginners/cant-get-lumex-oled-16x2-and-20x4-modules-working/?action=dlattach;attach=924982)
![](https://www.eevblog.com/forum/beginners/cant-get-lumex-oled-16x2-and-20x4-modules-working/?action=dlattach;attach=924986)
The datasheets (attached example) are extremely sparse, only mentioning some rough parameters and pinout:
![](https://www.eevblog.com/forum/beginners/cant-get-lumex-oled-16x2-and-20x4-modules-working/?action=dlattach;attach=924994)
These modules look like standard 16x2 and 20x4 LCD modules (aka
Hitachi 44780 style ), but with no contrast control (N/C) and no external backlight control ('PLEASE NC'). The latter seems to be because the boards have an in-built 5->12VDC boost converter -- I've measured pin 15 to be at 12V once the unit is powered, so I've left the last two pins unconnected.
Using the standard Arduino LiquidCrystal library I am able to drive an old 16x1 LCD I have sitting around, but switching those same wires over to one of these OLED units results in nil. Tried both 8-bit and 4-bit modes. Tried an older version of the LiquidCrystal library that was rumoured to be slower. Tried manually (jumper wires + buttons) clocking commands in, but for I all know I may have made mistakes doing this. Seems like nothing makes the display turn on.
These modules use a US2066 controller. Datasheet (attached) is pretty sparse on command information, so I again presume it's a Hitachi HD44780-compatible thing. It does support non-parallel modes (I2C and serial) however some of these modes require grounding a pin I do not have access to. I tried an I2C scanner anyway without any luck.
Digikey currently lists these displays as 8-bit parallel mode configured anyway.
Not familiar with I2C, maybe there is a better way of determining if it's so (any particular lines/patterns I can scope and expect to see traffic on power-on?)
Otherwise: am I missing something silly? Anyone ever used these modules before?
N.B. bought these years ago from Element14 because they were cheap (badly selling?) stock. Would Lumex care enough about me to answer an email? Might be worth a try.