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T35 only for debugging - minimal sockets?


#1

Hi again, I am using a Spider with a T35 for debugging purposes. Black screen with scrolling text outputting information as the system is running. Currently the T35 is occupying 4 sockets RGBT and I am thinking if it would be possible to disconnect some of them, when the required graphics is so simple.

And if disconnecting connections, how to inform the driver, and leave them for other purposes?


#2

You can disconnect touch but not the other ones.


#3

Interesting point.

I would assume that as the connections to the LCD are outputs only, you could boot up the devices headless after you had completed all the debugging?

Not sure about reconfiguring but if you recall, the default with the latest firmware is for the LCD to be disabled. I would assume at this point you could use the IO connections as their alternative GPIO.


#4

I was thinking that a black screen with only red letters would only require one socket?


#5

Nope. Any unconnected socket would have the connections floating and this is not a good solution.

You would also have to make sure that the HSYNC, VSYNC and CLOCK where on the same socket.

HSYNC and VSYNC are shared with the red connections but CLOCK is on blue. Green also have the shutdown controls.

Anyway, even if you could do this with RED only, the other control outputs from the CPU could not be used for GPIO.


#6

You could hardwire the shutdown pin on the Green socket of the T35. Not sure if it needs to be tied high or low (it’s used to turn on and off the back-light). Just cut a gadgeteer cable in two and solder the correct wires together. This should definitely get the display running.

It’s probably first worth trying to see if you can manually change the Green D0 to D5 Pins as regular outputs without corrupting the other colours on the display. Changing these should globally adjust the green level of all pixels on the display.