Always High State on Input GPIO- UART4_RTS - Camera Error #4

Robotics & Edge Computing Jetson & Embedded Systems Jetson AGX Orin
, ,
1

Hello Everyone,

I have noticed that UART4_RTS on camera connector has weird behaviour when it is configured as Input.
When I configured it as Input, the voltage was immediately pulled to 1.8V, but it shouldn’t because it is floating and pull-up is turned off. I checked it twice. What is more, when I connect external device’s gpio to this pin, it couldn’t pull it down, even with high drive on output(voltage drops to 1.6V).

Is there anything I might have missed?

cat /sys/kernel/debug/pinctrl/2430000.pinmux/pinconf-groups

...

158 (uart4_rts_ph5): 
	pull=0
	tristate=1
	enable-input=1
	open-drain=0
	io-reset=0
	rcv-sel=0
	io-hv=0
	loopback=0
	schmitt=0
	pull-down-strength=0
	pull-up-strength=0
	drive-type=0
	func=rsvd2
	pad-power=0

EDIT:
I found that CAM_ERRROR_4 has label VSYNC on the schematic. Is there any reason why?

Thanks in advance

2

Probably solution:

This should be changed in PINMUX, because it is easy to make a mistake.

But I still don’t know why this Pin is labeled as VSYNC.

4

Hi, it can only be output because of a buffer used on module as below showing.

image
image892×243 30.8 KB

5

Thank you.
It is as I thought, but do you know why it is VSYNC on the schematic? It doesn’t make sense since it is output and there is no timer there.

6

It is a inherited reserved design in which there is an unmounted bypass 0 ohm in parallel with buffer. In fact, it is used as RTS or output GPIO only. You can ignore the vsync word in schematic.

7

Thank you for the explanation!

9

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.