Your subject is miss-leading. You’re searching for a display.
Ah, you must mean, my use of “console”.
I was referring to the “linux console” (/dev/console), which is usually a VGA card in text mode on IBM PCs.
But yes, I guess I mean a display cape, or some kind of text only display hardware/software combo that linux
could boot with as the boot console, and allows fast screen updating.
You bring up some interesting things that sound good:
You can either use a text only display, ie with I2C or SPI interface.
I haven’t experimented with these – guess I should look into such devices with fast update rates.
I did fall across this which maybe looked promising in that it’s a device acting as a linux console:
It’s a bit under my spec; 40x16 instead of 80x25, and a bit small physically. But maybe I can find some
larger I2C oriented displays.
Or you can still use a HDMI monitor, since you need not disable all HDMI pins. Just keep one or three of them for a black & white frame buffer.
Hmm, that sounds cool.
Are there any docs to guide on how to tweak the HDMI virtual cape to black+white mode?
In my application I don’t need color.
BTW: The HDMI pins block PRU-1 GPIO. Only 16 inputs / 15 output are avialable.
Instead running on PRU-0 you can have the full set (17 inputs / 16 outputs) and HDMI in parallel.
Mmm, perhaps you can help clear this up for me; the BBB pin assignments definitely has me confused.
I did find this table which seems to show only 10 outputs available to PRU0 via register __R30,
and only 14 outputs available to PRU1.
Since PRU0 doesn’t compete with HDMI, I could use that, but that means I’d be limited to running 5 motors.
(5 x steps+direction = 10).
If I used PRU1, I take it I could run 7 motors (7 x steps+dir=14), but that means (I think?) stopping HDMI entirely,
so that my code can run in its place.
Is this correct, or am I missing something? Not sure how to get 16 outputs from one PRU, or how to do it
without disabling HDMI completely.
Thanks in advance for any clarity on this…!
I’m definitely drowning a bit in large PDFs and spreadsheets/tables, and trying to see my project fit into all this.