nanoDLP

Kvirre

Member

Registered: 2016-08-07

Posts: 47

Syscall Shutter on HDMI

Hi,

I found a way to enable / disable HDMI (shutter) through syscall on Linux Raspberry Pi and I would like to share it.
(I am using a LCD as a curing source)

Insert this is your "Shutter Open Gcode" and Shutter Close Gcode, and give it go.

[[Exec vcgencmd display_power 1]]
[[Exec vcgencmd display_power 0]]

Cheers

macdarren

Member

Registered: 2017-03-20

Posts: 411

Re: Syscall Shutter on HDMI

just curious...

In an LCD system how is this different from just turning off the light source?...does it actually power down the LCD is there a lag time to power it on before it can block the UV?  They consume very little power is this worth it?
I gather this cuts the HDMI signal to the LCD....does that help on the Pi? like power down the video drivers?

Kvirre

Member

Registered: 2016-08-07

Posts: 47

Re: Syscall Shutter on HDMI

Hi,

I now understand that most people use LCD's as masks.
For me however, I use the stock backlight (Daylight resin).

The shutter trick does not make sense when using the LCD as a mask.
But could be useful for projectors?

Anyway the operation takes 1 s to turn on, and instant shutdown.

Shahin

Administrator

Registered: 2016-02-17

Posts: 3,546

Re: Syscall Shutter on HDMI

Cutting signal to projector does  force it into power saving mode but after couple of minutes.

Kvirre

Member

Registered: 2016-08-07

Posts: 47

Re: Syscall Shutter on HDMI

Could be useful depending on the behavior of your projector I guess.