7i73 LCD shows rubisch

If you have the same display, we can compare notes/hal files if there's still an issue

Yes,
for now, for me, my test stallion is Andy's,
very easy to use
forum.linuxcnc.org/27-driver-boards/3385...isch?start=20#105606

Hello Peter,
I tested the Newhaven, unfortunately it's exactly the same problem
I checked the 3.3 V power supply, it is stable.
At startup, led of 7i73 red a cursor flashes, 1 Hz, in the top left on the oled.
After when the oled is piloted, the cursor remains present and disrupts the display at 1 Hz also.
With two 7i73, with a 5i20 or a 6i24-25.

That sounds like my behavior (display is cleared at power up and you get a blinking cursor in the top left )
except that as soon as the LCD component is loaded, the cursor is turned off.

Have you tried starting the LCD component by hand?

What is your servo thread rate? The OLED is about 50 times slower than the LCD in processing characters
and it might lose characters in some circumstances.
(including the LCD components startup code that turns off the cursor)

The OLED is about 50 times slower
? I'm amazed, I compare the timing interface of oled ea w204 xlg and lcd dem20485 fgh,
it's very similar: data setup time and data hold time for example

curiously I do not know the timing of the thread Andy does not specify
in his test:
forum.linuxcnc.org/27-driver-boards/3385...isch?start=20#105606

my motherboard is very fast, i3 7100

What is your servo thread rate ( I was testing at the default 1 KHz)
(the CPU speed is not important)

The slow timing on the OLED is the maximum time to process commands
600 usec on the Newhaven and in the 10s of usec range on LCDs