Interrupt battery after shut-down of Jetson TK1 with LCD

Autonomous Machines Jetson & Embedded Systems Jetson TK1
1

Hello,

In my design, I use un 10inch universal LCD with HDMI interface and capacitive multitouch. This is powered from +5V of Jetson TK1 board. Entire system is powered from +12V battery (LiPO type, 1800mAh) and works OK.
After Shut-Down the +5V isn’t interrupted and the power consumption of the DISPLAY (including back-lite!) is important and the battery is too fast discharged too fast. I cannot use a bigger battery and intend to include a power-off switch circuit with about 20 seconds delay so that to be interrupted the connection from battery. I think my solution isn’t one elegant and exactly solution…
Here are my questions:
a) Is it a signal on Jetson TK1 (maybe on GPIO), that can be used, after Shut-Down, for a command of the delay circuit (instead to chose an arbitrary delay with big capacitor or 555 timer)?
b) Is it a better solution with minimum of components, because I didn’t have sufficient space just for a small supplementary board?
Thank you very much for your advices.
Have you a very good year for many designs with Jetson TK1!
JB

2

My first thought is to look at how the front panel connector J1A1 has its green power LED pin 2 set up, along with any other LED. I have not verified, but it looks like the “+3.3V RUN” goes up or down with power on or off…such that it could control a MOSFET similar to the SATA LED on that same front panel header.

Looking at the schematic, I even see a note:

NOTES:
LVDS / EDP MODULES MAY USE +3.3V RUN
OR +3.3V_RUN GATED BY EN_AVDD_LCD (PMIC GPIO4)