7i73 Pendent Control

My LCD www.ebay.com/itm/190671615309

When I disconnect VEE from 7i73 and connect it to a potentiometer (according to the picture) the best contrast appears with ~1V on VEE. But with 7i73 the VEE voltage is not changed from lcd.00.contrast

Looks like the LCD comp scales and bounds the contrast value so that the lcd.00.contrast value must be between 0 and 1

And yes I change it from 32 to 191 (0x20 to 0xBF)

The only real change is when lcd.00.contrast is 0 - the pucture disappears (it sets 3.23V on VEE). All other values have no effect (that 0 thing works only in 0 and 1 modes)

PCW wrote:

Looks like the LCD comp scales and bounds the contrast value so that the lcd.00.contrast value must be between 0 and 1

That's right! Thanks!
I tried that too but I was not persistent enough - 0 and 0.1 and 0.3 did not work and I quit. But 0.4 would work!
Looks like LCD just disregards all values above 1.

andypugh wrote:

They shouldn't show

I mean they don't literally show, but they still take their digits, like invisible symbols. And it's on the man for \n "To print in the rightmost column it is necessary to allow the format to wrap and omit the \n code". That's no problem, but we can't use the same trick for | as the text wraps back to the current page.
If it wrapped to the next page, I could omit | where nesessary and live with that.