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Heavy Raspberry Pi User? Keep An HDMI-to-USB Capture Device Around | Hackaday

tagsEthernet Splitter Target

This is a simple reminder from [Andy], his Raspberry Pi project often travels with him outside the workshop: he recommends

. As long as there is a computer around, it can provide a simple and configuration-free way to view the Raspberry Pi's display. The display does not involve a local network and does not need to carry a spare HDMI display and power supply.

The usual way to view the Pi screen is to plug in an HDMI display or make a remote connection, but [Andy] found that he does not always have detailed information about the network he works on (assuming there is even an available network), and in any case, Configuring the Pi with the network details of the location is a hassle. He also carries an HMDI monitor and power supply, which he cannot do. On the other hand, plugging a small HDMI-to-USB adapter into his toolkit has brought him rich returns.

The way it works is simple: the device converts the HDMI video source into a certain behavior, just like the video stream of a USB webcam, which can be viewed on almost any desktop or laptop computer. As long as [Andy] can use some kind of computer, he can immediately check the display of Pi.

Many of his projects (e.g.

) The Pi camera module is used, so the quick way to view the screen is very useful for checking focus, previewing videos, etc. This is a real sweetness for him. We can't help thinking that it might be tempting to embed one of these small boards in it.

.

This is a clever trick. Will have to take one and throw it in my bag. I'm sure it will come in handy in this case. Thank you!

This is another tip, please visit your hifi store and get various HDMI adapters, such as HDMI Male to HDMI Male, Fmale to fmale and HDMI to mini + micro, as well as high-quality USB extensions, you will not need to carry a larger Bulky HDMI cable. I found that the capture device and some adapters can fit in a small headset bag.

If you use the GPU and tablet product packaging box to grab, although there may be several types. They are often thrown in.

I have thought of one of them for months, and I use it more than I expected. When getting a display on another device is as easy as opening a window on a computer, it does bring up some interesting possibilities.

Is it as easy as opening a window? I am curious which application is opening a window? I tried to "detect" the monitor with no luck.

Thank you!

That's because it is not a monitor. It will be presented to the OS as a webcam or imaging device, so please use the appropriate application. You can plug the "basic webcam software" into the search engine of your choice, or you can use an app like obs-studio, which may be too big an option for most use cases. I think that Windows 8, 8.1, and 10 have pre-installed the Camera application in the start menu.

I loaded OBS, which is too high at the moment. Before that, I used the Windows camera. For some reason, the camera would start and shut down. That's why I chose OBS.

@Fred

Did you "open the camera's application permissions"?

Or just use VLC

You can also convert these HDMI versions to USB devices via HDMI pass-through.

HDMI 1 to 2 splitter, about $10.

Does this ignore the safety bit?

This should not be the case. The USB device should be registered as a camera, not a mass storage device. I have, if you happen to have an old tablet, it should work too.

If it is not an unauthorized HDCP stripping program, the HDCP video cannot be decrypted. As far as I know, Raspberry Pi will not output HDCP, because the driver is open source, so it cannot be trusted for execution.

Yes, it will ignore it, you can capture Firestick running Prime video or netflix.

I have a USB-C powered monitor that I carry with me (hopefully it is smaller).

I mean, if he has already borrowed the keyboard and mouse from another computer, why not just unplug its monitor and borrow it?

Because sometimes another computer may be a laptop, or the monitor has a different interface, or all devices in a monitor that have no accessible interfaces at all are in it.

Why borrow money? The Ri8 (i8+) has a great small keyboard/touchpad combination. It is very compact, backlit, has radio frequency or Bluetooth version, and the built-in battery can be used for a long time. I found that their prices are not high, and they come in many different colors.

Amazon link:

Obviously, Synergy can also be used on RPi, which may be very good for HDMI USB adapter solutions

Well

I want to know what the delay is like.

Not that I am a tuxedo racer, but if there is a delay in the mouse or terminal, it will be a bit irritating

The delay may be somewhere between "outrageous" and "horrible", but this is not the main display-it is used for troubleshooting and configuration, and is usually headless.

this project:

Use the same or similar dongle for remote Web access. The delay is fairly discussed in the article.

Considering this is really surprisingly good. After Elgato's "Cam Link", they were called "Unlinkable".

Take a look at the EposVox video on YouTube, the title is "The cheapest capture card money can buy. Is it actually worth buying? (BlueAVS / Goodan USB 2.0 CamLink)". The delayed test puts it in the second second of the review.

In order to avoid connecting the monitor, I used it on a laptop several times and it worked well.

If they support UVC, you can also connect them to an Android phone.

If you have one, open it and make sure there is a small heat sink on it. If not, install one to avoid premature hardware failure.

I have been doing it for a while. My next step is to use Arduino pro mini/Leonardo to make a virtual keyboard for pi.

Pro Micro is usually the first choice for keyboard building; for examples of small open source options, see Gherkin or Reviung Design.

I'm using Teensy for the same operation, despite using USB->Serial input, so I can run it in Windows for specific use cases.

The screen that can hook the USB cable directly to raspi and let raspi provide it is not very good. Ideally, you can connect it to the computer above, or even a phone or tablet.

Waiting for the next version

It is already possible to simply set up raspi as an Ethernet device and use a remote client (ie tight vnc) to connect

If the network settings are not completely locked by the administrator on the host,.... But when the lock level is reached, you may also be prevented from installing new USB devices, or even idle unused ports.

Yeah. . I like that.

Or become a wifi access point yourself. Also cheap. No need to obtain permission or information from anyone. If you want to use a GUI editor on the pi to edit the configuration files owned by root, you can even start vncserver from ssh as the root. Of course, you prefer any resolution. No additional hardware is required.

Come here to talk about this. If no known or unopened wifi connection is found, my cyberdeck project will create a hotspot. Then I can log in via ssh or VNC via laptop, tablet, mobile phone, etc.

If HDMI is not connected to the monitor, RPi 400 will not allow me to connect vnc to the tablet!

Yes-suitable for any headless workstation/tower workstation. Bring one with you (together with the VGA->HDMI dongle) to diagnose the problematic system. Save the cost of finding an ambulance (if there is an ambulance on site)

I plan to get RPI4 and try to get the same result by using UVC gadget driver and USB in OTG mode (and Ethernet and audio source) without additional hardware.

Does this seem feasible? What are the disadvantages?

As an option, I am considering using RPI as a keyboard/mouse gateway to have only one set of input devices. Maybe it makes more sense to get RPI400 for this...

Interestingly, but you still need to supply power via usb-c, so now you need to use an improved y-cable or other local power supply (POE?). It may be easier to obtain RPI CM4 and find/design a breakout board that meets your needs.

Will these adapters cause significant delays? It would be nice to capture and run OpenCV on the output of these hdmi microscope cameras.

I found that with the new "cheap" stick, as in the photo, the time difference is negligible, maybe one or two video frames. There is a person on YouTube who will test this type of device and post the exact delay time.

Maximum input (4K) 3840×2160 8/10/12 bit color at 30Hz

Maximum output at 30 fps (2K) 1920x1080p

Output format: M-JPEG (each famous image is compressed into a single jpeg image).

There is a similar USB 3.0 HDMI capture device that can output up to 1080p at 60 fps with just a little capture.

There is no support for HDCP, which makes sense.

Any delay will be in the time required to generate the jpeg image.

In fact, at least one USB 3.0 version has better specifications and is priced at $12. Interestingly, after this article was published, the slower and more expensive version of the article sold out.

USB 3.0 is usually not USB 3.0. They are just a blue USB plug, not even extra pins. I have several different variants. Stick to the cheap USB 2 1.

3.0 is a scam, the same electronics inside + USB 3.0 plug :-(

Therefore, the same macro-silicon MS2109 chip can accomplish these two tasks at the same time. That's too dirty, thank you for your attention.

I want to know why at 10 times the data rate (~400 MB/sec and 40 Mbps/sec), it cannot accomplish 4 times the image size at 2 times the frame rate.

This is a single page description of the award-winning MS2109 chip:

feature:

enter:

HDMI 1.4b

Support DVI 1.0

Support HDCP 1.4

Support RGB444, YCBCR422, YCBCR444, YCBCR420 color space

Support dark 24/30/36

CEA-861-E / CEA-861-F

Max 3840×2160 at 30Hz

Output:

MJPEG

1920×1080 at 30Hz

User can customize

USB 1.1

UVC 1.0

Vocal:

SPDIF

Default 96kHz single channel

Mononucleosis

USB audio complies with UAC 1.0

Support shared input

USB 2.0 compliant device

Supported operating systems:

Windows XP / 7/8/10

Android 5.0

Apple system

Only need additional 24MHz external crystal oscillator hardware to work

Internal PLL

power:

Built-in power-on reset circuit

Internal LDO 3.3 V

package:

QFN-48 (7mm x 7mm)

RoHS compliant

Search for "ad83504c-4884-46b2-85ee-2c93c68d8cd5" to find the Chinese image of the data sheet summary I translated above by using the camera on the android phone with the Google Translate application.

Some youtube reviewers tested them using obs-studio, and their latency was 48 milliseconds.

(Reference: at 4 minutes and 16 seconds

And the S/W used is

or

).

We are using something that is almost identical to the one in the picture in the church. When the guy displaying the music on the screen changes, there is a delay of at most a few milliseconds (maybe no more than 10) milliseconds before the streaming software has a new view and processes it. Very basic. Don't know how fast you need to capture for OpenCV, but it basically requires any HDMI and makes it a webcam without much lag.

It must depend on the hardware you get-my cost is 17 euros, but it can't be used compared to live vidao, because the delay is about 4-500ms compared to the audio directly obtained from the mixer. too frightening..

This is a beautiful display of the perception-driven approach. Hal basically used it for slide shows and underestimated the delay, while Brian used it for motion pictures and overestimated the delay. Who is right? Obviously both! They do a good job of enclosing your expectations of the equipment. :)

In my experience, the "unavailable" delay comes from sources such as cameras, not from HDMI sticks. Therefore, you need to both route audio through the camera and add hardware or software delays to the audio path.

To test my hypothesis, directly connect some HDMI hardware monitors to your signal source, and then compare the image with the real-time scene.

If you also need a keyboard and mouse, and need to carry a laptop to use with the HDMI capture card, you can check KeyMouSerial:

EspUSB is also a good choice for USB keyboard and mouse over WiFi via phone.

Long before the hdmi-usb dongle began to appear, we have been looking for such projects.

Thanks for posting the link! This will be in my list of Christmas items.

You can also use Synergy to reuse the keyboard and mouse of the mainframe.

Noooooo, how can I miss this before I start building the same thing effectively?

I have passed basic numbers and letters as a virtual keyboard.

Your project is very useful, and it is a bit embarrassing for me personally, because your project already provides everything I need, and there is more. I am very angry, I missed it in my research because it seems to fit what I want.

Thank you, you may have saved me the ongoing work time of a project destined to be "at best".

By the way: Am I the only user with serious Ethernet problems in Raspberry PI 4 when a USB device is connected? In 1Gbps mode, my loss is more than 30%, while in 100Mbps mode, about 5% of data packets are lost. However, if I disconnect the USB, everything will be like a spell.

Try to place the ferrite choke on the USB cable as close to the pi as possible; make sure that the power supply rating you use includes additional USB power consumption.

It may also be the interaction between the frequency of certain screen resolutions and the network and USB devices causing additional antennas to pick up more signals to drown things out.

This happens even if there is no monitor connected.

It may be found that its function is related. I ran into a problem on the older pi because my power supply dropped to 4.9v. It is enough for the cpu, but not enough for the reliability of the Ethernet. New psu. Consistent 5.1v, the problem has been solved

Well, this is the one that comes with RPi 4...

These are very neat, and I can use Pi 4 as a KVM some time ago. These are two different projects:

Hackaday launched the second in July:

I was a little surprised [Michael Lynch] (TinyPilot) used a self-developed "USB-C Splitter Box" [1] to power the Pi and OTG-KeyMou of the server through a single USB-C connector of the Pi.

Would it be easier to power the Pi through the 5V pin on the pin header and cut the +5V wire of the OTG-2-server cable?

Pi can get all the power it needs, and can protect Pi and the server from the "stray" current flowing between them.

Am i missing something?

[1]

>Just cut the +5V wire of the OTG-2-server cable?

I think this is basically his separator box. Beautiful housing with a connector for the cable for the 5v cutting line, where the 5v line is connected to the second USB-C connector to power the Pi. At least this is what I did (only use shrink tubes around the cables, not fancy boxes, and use solder instead of connectors).

Not sure which Pi model can use USB anytime, anywhere, but I'm sure I saw someone using a tablet with an SSH client and connecting directly to the pi via USB OTG.

As far as I know, both pi zero and pi 4 models can perform USB OTG. I think the computing module can also do it, but because of the built-in USB hub, all other pi models cannot do it. As a coin purse, as a coin purse, I have been plagued by the Ethernet problem on the USB, which interrupted my SSH session a lot.

A tablet or mobile phone with OTG and at least Android 6 can directly use the capture card and use it as a monitor.

This is a good reminder. I recently bought one from Amazon.

But I encountered a problem, but did not find his solution.

When I connect it and use VLC to view the capture, the output is very rough and it is difficult to read any text. However, if I use OBS with good quality, the output is very good and clear.

Any ideas VLC settings might be problematic.

My guess is that you are using "MJPG" (Motion-JPEG, compressed) instead of "YUYV" (YUYV 4:2:2)

v4l2-ctl -d 2 –list-formats-ext

I used this trick to set up TX2 to click on the stupid user agreement menu/initial ubuntu settings. Although it's clumsy, it's better than carrying an entire monitor with you to complete a task.

Will these things be captured in 4:4:4 color space? If not, you may find that the small colored text is blurry.

I can't believe these things are only $6 on Amazon. Love Moore's Law.

Or Moore's Law

"If x is enough, then too much is right!"

B ^)

Only $12 and get change on Amazon? ! ? Shh, I remember that an NTSC capture device cost me a few hundred dollars (I think that was a deal). Although it seems not very early for this old man, it is probably 20 years ago or more. Since then, many changes have taken place in computer and video technology.

I think I will get one, even if I am really useless!

I linked my Pi 400 to -> micro hdmi to hdmi cable -> hdmi capture card to usb -> usb to usb-c adapter -> Samsung note20 ultra (using the usb camera pro app) to turn the phone into a portable display ! There is almost no noticeable lag.

This sounds absolutely terrible.

For this, I have been using one of them. Recently it was mainly to test my MiSTer settings. I use VLC, but I need to make some settings every time, so I can choose the correct resolution and other settings. It can execute YUY2 at a resolution of 1920×1080, but it can only be played at a speed of 5fps, and you must switch to MJPG to get 30fps at that resolution. Lower resolution can perform 60fps in MJPG. It is also suitable for capturing screenshots or videos without installing other software on the connected device. Audio will also pass, just make sure to select the correct audio device.

I tried to connect the Raspberry Pi 400 to an Android phone using an HDMI capture card, and I also tried a tablet, but I couldn't hear the sound like when connected to a TV. As you mentioned, how do I "choose the right audio equipment"? I don’t see any options in the USB Camera App on my Android device. The video works, but I need to lower the default resolution of the Raspberry Pi to work properly.

mark

Another convenient dongle is the HDMI to composite video adapter. I found a trademark with the Black Web brand name on Walmart. I still occasionally encounter a conference room with an old NTSC composite video projector input VCR or anything else, but when disassembling the Crestron or AMX room control panel, there is no other easy-to-obtain shading phenomenon. This shocked librarians, administrators and administrators. like. As long as you don't keep your presentation busy with small fonts (and don't do it anyway), it will work well. It is also very convenient to have a male/female BNC-RCA pin jack adapter.

I converted HDMI to VGA, VGA to component, component to composite signal, and composite signal to RF modulator's 3rd channel routing, as long as you use CGA colors and 320×240 scaled fonts. ;-)...Although, in reality, converters were annoying and very muddy in the late 20th century, but nowadays, you can usually tell anything that runs at 800×600 resolution on a TV.

Using the otg adapter can easily use my phone as a screen. Never thought about it. Thank you!

I have been using it for a while. Unfortunately, my super cheap capture card is actually a TV capture with HDMI to composite converter, so I need to add hdmi_safe = 1 to config.txt and deal with poor resolution/bad colors.. I Tend to try to enter text on a laptop instead of a USB keyboard.

I have been paying attention to the serial USB keyboard adapter, but it is expensive

"If you own a second computer, you can purchase equipment to view the first computer." The system that requires you to use the computer as a monitor is defective.

I was very excited to get the first Raspberry Pi many years ago. Then I realized "Oh, I need to buy another monitor because of HDMI." Noise is eliminated. I think Pi's focus is on developing countries and so on. Is HDMI a third world standard? I have never touched it.

Isn’t it the old and the new? In the late 1970s, you might connect a TTL gadget to a Z80 stimulus terminal, which might be just as smart, and at some point in time might have more RAM than a micro terminal. Another method is to displace the screen and lose half of the CPU capacity. It is very common that the display processor actually contains the processor. There may be 3 to 4 TVs in modern TVs, even non-smart TVs, there is a broken TV board with 2 RISCs or other things around, and an ARM.

Before I forget, if you want a minimal TV output terminal now, a VCR from the 1990s to 2000s with on-screen display and/or subtitles might have a nice small display processor with one or two RAM for each screen, character generator, etc. Those nonsense Yoink, this is a single-chip video solution for arduino, 8-bit, etc.

I think if you can install the code to run some random junkyard displays discovered by bit tapping, then, what is your original problem?

Not sure what you are talking about. You don't need the screen on the Raspberry Pi at all, except for the screen I bought to drive a specific screen, none of mine. But I don't have the kind of settings to use this screen as UI. For the actual work on the device, I want to think about it. If you need to connect to the screen for some reason, the dongle is just a lovely way to use the existing screen.

I don't think the whole significance of Pi lies in developing countries. Maybe you are thinking about something like OLPC.

I think you are living a brave life without HDMI.

The "point" is that even if you "ssh in", you use your computer as a monitor.

Sorry, you did not get the memorandum about developing countries.

My TV has HDMI, but you know the priority...

Still not sure what you are talking about. Do you want a version of Raspberry Pi that can meet various requirements with its zero output capability? Or do you want the Raspberry Pi to have an integrated display, so you want to increase the price significantly?

Can you forward me the memo that Raspberry Pi is only suitable for developing countries? They have been using HDMI since it was invented, so do I think their work is really bad?

Jeez, man, my point is that they have been using HDMI instead of the more common barebones. A few more wires are required instead of a monitor (or a complete computer as suggested in this article).

memorandum?

Dunno, why can’t I directly reply to your post, but... Although HDMI devices cannot be used in developing countries for some reason, there are still many people using Raspberry Pi units for projects in developing countries? I don't know. For me, this does not mean "I think Pi's focus is on developing countries."

The original RPi uses a standard RCA connector with video output.

RPi B+, RPi 2, RPi 3 and RPi 4 all have composite video, which now happens to be hidden in the "quadrupole stereo output and composite video port".

RPi Zero has an unfilled 2-pin header, labeled TV composite video.

The "sdtv_mode" in /boot/config.txt can be used to adjust the output to keep it consistent with the default value NTSC.

Why do people call it "RPi screen"?

RPi has no screen. It may have a video output port to which you can connect a monitor, but the RPi is just a "box". Does not have its own built-in video screen. These comments are extremely misleading.

I think my best Raspberry Pi accessory is the $3 ubec that I use as a power supply. I have never used the USB port to power the Raspberry Pi. I don’t even think I have a USB adapter that can power the product, but I already use a car battery to power it.

I think when you don’t have a spare monitor, it’s a good idea to use USB to capture widgets. By the way, this is why I still don't power the pi4.

Therefore, I don’t need to "carry a monitor and a spare HDMI cable with me", I just need to take a whole spare computer (with a monitor and HDMI cable) with me? Makes sense. WTF.

Good job...I ran into the same problem, but the solution was slightly different.

I have been using "Smoopi" (

) To run a lot of 3D printers/factories/etc. These printers/factories are usually in schools and/or institutions, which is usually difficult to obtain network approval (and after doing so, it is difficult to obtain services).

Therefore, I have started using wifi settings to set up all installations to find my phone/tablet hotspot and try to connect when found. Then, I can SSH and perform any updates (even automatic updates, etc., because it is sharing the phone's Internet), then disconnect and the machine can run again. In this case, the risk of these machines being hacked is very small (if you can access wifi, you are likely to have direct access to the hardware), and they are usually not connected to the network.

Ok. There is cheap mail. how to use?

Start software that can use the camera, such as Skype.

I downloaded OBS and am using it.

Another benefit of this setting worth mentioning is that it is trivial to record the output using the video recording/webcam software of your choice. This feature is especially useful when Rpi scrolls through some error messages quickly at startup.

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