I have my pi 2 running Kali 2.0.1 which is hooked to a 7in tft sun founder screen. The problem is that when unhook in micro USB port to power the pi is still running so in order to turn my pi off I have to unhook the hdmi and micro USB so shut my pi down.
Asked
Active
Viewed 1,858 times
2
-
Is the pI realy still running or is the monitor just displaying the last received image? – Havnar Jan 12 '16 at 10:51
-
1Wait. What? Wha... Why? I don't think HDMI can power anything*. I agree with @Havnar. The display may just be displaying the last image received from the Pi. – Aloha Jan 12 '16 at 13:05
-
Does the Pi itself still light up (red light on the pi) with only the HDMI cable connected? – Aloha Jan 12 '16 at 13:06
-
the pi2 still works as if the micro usb was still in i can browse the web run commands and everything else u can think of i can do with the hdmi powering the pi. – laxus Jan 12 '16 at 19:07
2 Answers
1
I think it's all about the red light. You can issue the sudo shutdown -h now
command and when you see system halted
message it is safe to turn it off by removing USB. Taken from here. Not a bad idea is to add a button to the pi that will power on and off the device. Then add a shutdown script to turn the power led off echo 0 >/sys/class/leds/led1/brightness
. This will not tell you the exact turn off moment but will turn off the led.
1
It would seem that your monitor has the newest HDMI, that can power a device connected to it. The new HDMI format supplies 5v to a pin. How to turn it off is beyond me. Maybe check the monitor's manual.

Garnett Haines
- 315
- 1
- 2
- 4
-
It is true that an HDMI source (e.g. a Raspberry Pi) must supply at least 55mA on the 5V line to the sink (e.g. a TV or monitor), but I can not find any reliable information anywhere that the sink (e.g. a TV) can/does provide the source (e.g. a Raspberry Pi) with power. What specification (or article) says that "the new HDMI format supplies 5V to a pin"? – Toothbrush Mar 04 '17 at 20:17
-
The only specification I can find which supplies power over a video cable is MHL (Mobile High Definition Link). This interfaces with HDMI, and several manufacturers (including Samsung) have shipped devices supporting this standard. – Toothbrush Mar 04 '17 at 20:18