Peterborough Linux User Group (Canada) Forum

Linux & Android => Raspberry Pi & Single-Board Computers => Topic started by: fox on January 05, 2021, 08:23:05 AM

Title: Use your Android phone or tablet as a Raspberry pi display
Post by: fox on January 05, 2021, 08:23:05 AM
I had no idea one could do that until I saw this (https://www.youtube.com/watch?v=nui8kXvUAys) YouTube video. All you need is a USB to HDMI capture device (as cheap as $13 on Amazon), an adapter to plug the USB end into the phone or tablet, and a screen capture software app. The only negative is that when the display device is being used, you don't have touch screen capability. So if you have an 8" Android tablet like I do, is it better to use this or to buy something like a 7" touchscreen made for an RPi?
Title: Re: Use your Android phone or tablet as a Raspberry pi display
Post by: ssfc72 on January 05, 2021, 10:07:04 AM
Very neat, thanks for posting, Mike.  The sound from the Pi 4 also gets output from the phone or tablet.
If a person needs the touchscreen function, then they would have to go with a touchscreen display made to work with the Pi 4.  I think the touchscreen displays need to access some of the IO pins of the PI 4 as well as the hdmi?
Title: Re: Use your Android phone or tablet as a Raspberry pi display
Post by: fox on January 05, 2021, 10:51:55 AM
7" touchscreens for the RPi can be had for about $70. The capture device plus adapter would be a lot cheaper, though less functional because of the loss of touch. On the other hand, if you already have a monitor that works with HDMI, that is the cheapest option, though not so portable. I ordered a Pi 4 (4gb), but I don't know what I'm going to do with it yet, other than try different things. A small, mobile monitor would be useful just for setting up the pi for some function that can run headless (like a server). So at some point, I'm going to look into one of these options.
Title: Re: Use your Android phone or tablet as a Raspberry pi display
Post by: Jason on January 05, 2021, 12:49:36 PM
You can also get USB keyboard/touchpad unit. I have one that works fine with the RPi. I think it cost me $30 at that electronics place upstairs in the mall. It has a USB dongle that plugs into the Pi and keyboard which is the primary reason I bought it (but for an Android box). But it also has a small touchpad on it.
Title: Re: Use your Android phone or tablet as a Raspberry pi display
Post by: ssfc72 on January 05, 2021, 02:15:35 PM
Yes, I got one of those as well, from Amazon.  Mine is called a Rii and has a back lighted keyboard.  Works very well with my kodi box and my RPi.
Title: Re: Use your Android phone or tablet as a Raspberry pi display
Post by: Jason on January 06, 2021, 08:31:36 AM
Quote from: fox on January 05, 2021, 10:51:55 AM
A small, mobile monitor would be useful just for setting up the pi for some function that can run headless (like a server).

If you're planning on doing that, you just need to set up up ssh on it and then login via the terminal using any display you like. Once you have that setup you never need a monitor again. I believe that RPi may even have an option to setup ssh server this on during and after install.
Title: Re: Use your Android phone or tablet as a Raspberry pi display
Post by: fox on January 06, 2021, 10:22:07 AM
Thanks, Jason. I will try this when my Pi 4 arrives. That's a better plan than spending $60-70 on a portable monitor that I wouldn't need otherwise. So the way I would do this is to SSH from my computer to the Pi?
Title: Re: Use your Android phone or tablet as a Raspberry pi display
Post by: Jason on January 06, 2021, 07:55:45 PM
Quote from: fox on January 06, 2021, 10:22:07 AM
Thanks, Jason. I will try this when my Pi 4 arrives. That's a better plan than spending $60-70 on a portable monitor that I wouldn't need otherwise. So the way I would do this is to SSH from my computer to the Pi?

That's correct. You may have only the use of the terminal commands but it depends on how SSH is configured. If you look back to the notes for my presentation on SSH in the Forum somewhere it will help you get it set up graphically.
Title: Re: Use your Android phone or tablet as a Raspberry pi display
Post by: Jason on January 07, 2021, 07:07:55 PM
I forgot that the Raspberry Pi OS will let you setup VNC too which will let you control it remotely using the graphical interface. This page (https://www.raspberrypi.org/documentation/remote-access/) at the Raspberry Pi site shows you various remote options.
Title: Re: Use your Android phone or tablet as a Raspberry pi display
Post by: gmiller1977 on January 07, 2021, 08:49:17 PM
I've used this, and while a bit pokey, it's perfect for graphical administration.

Title: Re: Use your Android phone or tablet as a Raspberry pi display
Post by: ssfc72 on January 08, 2021, 04:47:49 AM
Thanks for posting that Link Jason.  I will have to try that out.

I have one of my RPi 3b set up as a driveway surveillance camera, using an older usb web cam. The Pi is running the MotionEye software surveillance program.  I bring up the video feed on my devices, daily, to check on things in front of my house. It is a great tool to have.

I access the video feed and the MotionEye program settings by typing the IP address of the RPi, into the browser address bar on any device.  So maybe I am already remote logging into that RPi?
Title: Re: Use your Android phone or tablet as a Raspberry pi display
Post by: gmiller1977 on January 08, 2021, 11:00:39 AM
MotionEye is running a web service to send you live feeds from the camera. 
Title: Re: Use your Android phone or tablet as a Raspberry pi display
Post by: Jason on January 08, 2021, 02:53:33 PM
Quote from: ssfc72 on January 08, 2021, 04:47:49 AM
I access the video feed and the MotionEye program settings by typing the IP address of the RPi, into the browser address bar on any device.  So maybe I am already remote logging into that RPi?

Yes and no. If you're outside of your network, you're remote logging into it and some would say it's remote access but it's not how computer professionals use the term because you don't have full control. You can only control what MotionEye lets you control. It's serving you webpages that include the video feed. I don't know if it's interactive. Can you just see the feed or can you interact with it by clicking buttons and such after you've logged in? Even then, it's just one or several interactive webpages like this Forum is. You can interact with it, enter a comment, attach a file, delete a comment and such. And I have more options that you can't see. Actually, you do too, since I made you an administrator in case COVID-19 kills me. ;-)

Maybe this definition (https://www.techopedia.com/definition/5553/remote-access) explains it better than I can.
Title: Re: Use your Android phone or tablet as a Raspberry pi display
Post by: ssfc72 on January 09, 2021, 02:25:15 AM
Yes, the MotionEye program on the RPi is serving up the video feed from the usb webcam, using my home wifi network.
As a test, I disconnected my ISP modem from my network and the video feed from my RPi is still accessible by my notebook computer/devices.  So I don't need to be connected to the outside internet, to view my RPi video feed.

Quote from: gmiller1977 on January 08, 2021, 11:00:39 AM
MotionEye is running a web service to send you live feeds from the camera.
Title: Re: Use your Android phone or tablet as a Raspberry pi display
Post by: ssfc72 on January 09, 2021, 02:32:13 AM
When i type the RPI IP address into the browser address bar, I can see the usb web cam video feed and I can also access the various settings of the MotionEye program.
I don't believe I can access the underlying RPi OS, that the Motioneye program is running on.  Perhaps I would need to SSH into the RPi, to do that?

Quote from: Jason Wallwork on January 08, 2021, 02:53:33 PM
Yes and no. If you're outside of your network, you're remote logging into it and some would say it's remote access but it's not how computer professionals use the term because you don't have full control. You can only control what MotionEye lets you control. It's serving you webpages that include the video feed. I don't know if it's interactive. Can you just see the feed or can you interact with it by clicking buttons and such after you've logged in? Even then, it's just one or several interactive webpages like this Forum is. You can interact with it, enter a comment, attach a file, delete a comment and such. And I have more options that you can't see. Actually, you do too, since I made you an administrator in case COVID-19 kills me. ;-)

Maybe this definition (https://www.techopedia.com/definition/5553/remote-access) explains it better than I can.
Title: Re: Use your Android phone or tablet as a Raspberry pi display
Post by: ssfc72 on January 09, 2021, 02:39:59 AM
I think I will buy one of those HDMI capture devices for my RPi.  It would be inexpensive, handy to have device, to view a video output of the RPi, without having to setup SSH or VNC.

Quote from: fox on January 05, 2021, 08:23:05 AM
I had no idea one could do that until I saw this (https://www.youtube.com/watch?v=nui8kXvUAys) YouTube video. All you need is a USB to HDMI capture device (as cheap as $13 on Amazon), an adapter to plug the USB end into the phone or tablet, and a screen capture software app. The only negative is that when the display device is being used, you don't have touch screen capability. So if you have an 8" Android tablet like I do, is it better to use this or to buy something like a 7" touchscreen made for an RPi?
Title: Re: Use your Android phone or tablet as a Raspberry pi display
Post by: Jason on January 10, 2021, 06:14:50 PM
Quote from: ssfc72 on January 09, 2021, 02:32:13 AM
I don't believe I can access the underlying RPi OS, that the Motioneye program is running on.  Perhaps I would need to SSH into the RPi, to do that?

Yeah, I didn't expect you could. And yes, you could SSH in and run terminal commands just like you had it hooked it up to a monitor.