How to control the GPIO to output the pull-up/pull-down level

Hello,I need a timing signal which from GPIO to control the capture of the external camera,when high level,the camera start capture and low level turn off

thank you everybody

You can refer to this topic even thought it is for TX2:

@Trumant,thank you very much ,can you tell me where can I find the tx2-j26-header-pinout? I only find the j21

Please find the info in this doc:

@Trumany I get it ,thank you very much!