About how to use GPIO of TWR-KM34Z50M

[jun1]

Hello.
This board drives a liquid crystal, but my application wants to use GPIO without using a liquid crystal. So I'm going to pull out the GPIO signal from the card edge connector of the board, but can I disconnect the LCD?
If it is necessary to disconnect the connection, a zero ohm resistor will be in series with the line, so if I disconnect it, can I disconnect from the LCD?
Looking at the circuit diagram, as an example
Card edge SECONDARY D44 pin: LCD43 / PTC4 has R121.

Thank you.

[jingpan · Accepted solution]

Hi jun,

It is hard to disconnet LCD. As you can see in the schematics, KM34 is connect with LCD panel directly.

You needn't add R121. Because it is default connected by wire. Do you notice the little blue point on the resistor symbol?

If you just want to do some developing or testing work, you can use these pins for are short time. But please notice that long time DC on LCD panel will cause liquid crystal molecule decompose and electorde aging.

Regards,

Jing

[jun1]

Thank you for the quick response.
Is it wired? OK. As LCD is not used, it may be deteriorated.
Thank you very much.

jun