Max 2 and Raspberry Pi monitor mode

[everalm]

Quick question, has anyone managed to use the HDMI as a monitor function with a Raspberry Pi..?

I have a Pi Zero that connects up via HDMI with no problems to a regular monitor

The cable from the Max2 box connects the Max 2 to a Dell laptop and a MS Surface 2017 without issue

Connect the Max2 cable to the Pi and it fails to connect and I get and error message telling me to "check the cable"

Obviously the cable works, the Pi HDMI out works so..... ?

Thoughts..?

[Randy11]

Hello,

On the Raspberry Pi, look at your '/boot/config.txt' file where you can adjust some values when the detection is not done.

Look here : https://elinux.org/RPiconfig#Video

Very good idea I have 4 RPi, this could be a very good solution for me.

[everalm]

H'mmmmmm

Adding " hdmi_safe=1" which now fixes the "your cable suck" error message.

Now I get you need more power "Monitor more power consumption. It is recommended to use 5V/2A ac charging" and a black screen

[Randy11]

Charge you Max2 at the maximal level or better, use a power supply with it.

[Randy11]

Verify that the power supply of the Raspberry Pi Zero has enough power, try 5 V / 2.5 A.

[sogaiu]

Originally Posted by Randy11

Very good idea I have 4 RPi, this could be a very good solution for me.

If the Monitor app on the Max 2 can support touch for the purposes of typing (on-screen keyboard) as well as providing pointing device capability, this would be even nicer

[mdp]

Originally Posted by Randy11

Very good idea I have 4 RPi, this could be a very good solution for me.

With a detail to be made apparent: that the Raspberry Pi 3 is halfish the performance of a RK3288... So it depends on what you have to do with it. You may need to get a Linux desktop or something - or just interacting with a server -, right, but you may be training a truck with your car.

[mdp]

Originally Posted by everalm

Adding " hdmi_safe=1" which now fixes the "your cable suck" error message

I do not have my notes with me, but be sure to also specify the right hdmi_group and hdmi_group - you will have to try and verify those which work best (like hdmi_group=2, hdmi_mode=73 , if supported by the Pi Zero).

Maybe also try the hdmi_force_hotplug .

[mdp]

Originally Posted by sogaiu

If the Monitor app on the Max 2 can support touch for the purposes of typing (on-screen keyboard) as well as providing pointing device capability, this would be even nicer

I concour: «What is left to do is an implementation of the touchscreen as a pointing device, so instead of being forced to a mouse (pad etc.) one could use the pen or finger to interact with the desktop icons, application controls etc. As Onyx recommends to connect the USB cable anyway... »

What we can do in this state, together with raising a feature request to Onyx, is the following: having an idea of how to send raw data ( "up|down, x, y" ) through a USB cable from the tablet to the desktop. That being clear, it should not be difficult to implement it.
If MTP supports control commands, maybe...

If you have ideas, post them in the "Monitor" thread.

[Randy11]

Originally Posted by mdp

With a detail to be made apparent: that the Raspberry Pi 3 is halfish the performance of a RK3288... So it depends on what you have to do with it. You may need to get a Linux desktop or something - or just interacting with a server -, right, but you may be training a truck with your car.

I can push the car

More seriously, it could be useful for a RPI used like a black box without screen or to debug. The Max2 is more convenient to see what happen than a LCD display to move from one room to another. I understand with your comment that is a limited usage where VNC is not sufficient or possible.

Thanks for the warning.

[everalm]

Power message seems to be a red herring

Had both the Max2 and Pi plugged into 10W 5V supplies, same message
Still so powered, added HDMI_group=2 and HDMI_Mode=68 (1920x1200 reduced blanking), same message

If this was a real power issue with the Max or the Pi it would expect it to show when I connect the Pi to the external LCD or the Max to the Dell PC or MS Surface Pro

[mdp]

Originally Posted by everalm

Power message seems to be a red herring

Had both the Max2 and Pi plugged into 10W 5V supplies, same message
Still so powered, added HDMI_group=2 and HDMI_Mode=68 (1920x1200 reduced blanking), same message

If this was a real power issue with the Max or the Pi it would expect it to show when I connect the Pi to the external LCD or the Max to the Dell PC or MS Surface Pro

Nonetheless, try and see whether
config_hdmi_boost
makes a difference. (In my experience, it did)

[everalm]

Alas, no joy, current settings are

hdmi_force_hotplug=1
hdmi_ignore_edid=0xa5000080
config_hdmi_boost=9
hdmi_group=2
hdmi_mode=22

Pushed boost to 11 (shades of Spinal Tap) without success
Also tested both with and without hdmi_safe=1

[sogaiu]

I've tried without success so far -- but haven't tweaked config.txt yet.

Is it possible something from:

https://www.raspberrypi.org/forums/v...ic.php?t=24679

might help?

Are we not interested in a resolution which is 2200x1650?

[sogaiu]

According to display properties reported here, framerate in Hz is showing up as 33.0 Hz. Is that what other people see?

May be using something like the folllowing will get us somewhere:

hdmi_cvt=2200 1650 33

According to the thread mentioned earlier, doing:

tvservice -m DMT

may tell us the custom mode number.

Apparently testing is possible using:

tvservice -e "DMT <whatever-we-got-as-sane-output>"
fbset -depth 8 && fbset -depth 16

With that in hand, we might set:

hdmi_group=2
hdmi_mode=<whatever-we-got-as-sane-output>

in config.txt (possibly along with other things).