Linux 5.11 Adding New Driver For Another Budget-Friendly, LCD Character Display

[phoronix]

Phoronix: Linux 5.11 Adding New Driver For Another Budget-Friendly, LCD Character Display

Adding to the Linux 5.11 changes and set of new drivers is "lcd2s" as a driver for supporting a 20x4 LCD character display connected via SPI/I2C and with this support can serve as a kernel console output device...

http://www.phoronix.com/scan.php?page=news_item&px=Linux-5.11-Modtronix-lcd2s

[ayumu]

Isn't this an hd44780 ? They're like $1 on the usual chinese shop. Maybe a few cents more with i2c interface.

[mlau]

When I was at university, every 2nd semester student had to program these with software-generated i2c over gpio pins. fun times...

[abott]

Isn't this an hd44780 ? They're like $1 on the usual chinese shop. Maybe a few cents more with i2c interface.

In the article picture, it probably is.

I have roughly 30 of these displays around for arduino projects, and use them often.

[danmcgrew]

I have accumulated many other LCD-display configurations over the years, e.g., 40 X 2, 20 X 1, 20 X 2, ...
How would anyone easily determine if Linux supports other display formats?

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This is really good, helpful information (especially to people who embrace both software and hardware design; I'd like to see more articles such as this on this site. Thank you very much, Michael.

[danmcgrew]

Isn't this an hd44780 ? They're like $1 on the usual chinese shop. Maybe a few cents more with i2c interface.

The HD44780 is not a display, but an LCD controller chip created by Hitachi in the late '70s / early '80s, which has enjoyed wild popularity, and has been "second-sourced" by innumerable manufacturers.
It has probably been used in almost every character-based LCD display ever made; and It's most likely right up there with the '555 and '741, as far as popularity (among commercial designers) goes. BUT...you cannot expect to get a specific display by saying, "Umm, I want one of those HD44780 things..."

[OneTimeShot]

Ok - I'll bite... Why does this thing need it's own specific Kernel driver? Why can't this just be a vanilla USB or PCI device accessible via a user mode library?

[Michael]

Ok - I'll bite... Why does this thing need it's own specific Kernel driver? Why can't this just be a vanilla USB or PCI device accessible via a user mode library?

Kernel console support with it. As mentioned in the article, there are already user-space libraries for normal functionality.

[Mez']

If they could do something about the iMon VFD, it would be great as well.

I have an old Antec Fusion 430 HTPC case for my desktop (still beautiful 15 years later), and the VFD thingie is too much of a mess playing with between lcdproc and LCDd, daemons to start manually or config files to tinker with. It would also hinder proper suspend/resume because of that daemon. Or it would stay lit when suspend, or not turn back on when resuming.
3 years ago, when I upgraded, I tried once again to make it work with some sort of automation, but I quickly gave up. I'm kind of used these days to have the thing turned off, but still... Would be cool.

[kpedersen]

Does anyone know of something like one of these but with a screen size of 80x25?