Streaming Video From An ESP32

The ESP32, while first thought to be little more than a way of adding wireless capabilities to other microcontrollers, has quickly replaced many of them with its ability to be programmed as its own platform rather than simply an accessory. This also paved the way for accessories of its own, such as various sensors and even a camera. This guide goes over taking the input from the camera and streaming it out over the network to multiple browsers.

On the server side of things, the ESP32 and its attached camera are set up with MQTT, a lightweight communications protocol which uses a publish/subscribe model to send information. The ESP32 is configured to publish its images only, but not subscribe to any other nodes. On the client side, the browser runs a JavaScript program which is able to gather these images and stitch them together into a video.

This can be quite a bit of data to send out over the ESP32’s compact hardware, so there are some tips and tricks for getting more out of these little devices, including using an external antenna for better Wi-Fi signal, or omitting it entirely in favor of Ethernet. As far as getting a lot out of a tiny microcontroller, though, leveraging MQTT really helps the ESP32 go a long way. These chips have come along way since they were first introduced; they’re powerful enough to act as 8-bit gaming consoles too.

Thanks to [Surfskidude] for the tip!

Using An Old Smartphone In Place Of A Raspberry Pi

The Raspberry Pi was a fairly revolutionary computing device when it came on the scene around a decade ago. Enough processing power to run a full Linux desktop and plenty of GPIO meant almost certain success. In the past year, though, they’ve run into some issues with their chip supplier and it’s been difficult to find new Pis, which has led to some looking for alternatives to these handy devices. [David] was hoping to build a music streaming server and built it on an old smartphone instead of the ubiquitous single-board computer.

Most smartphones are single-board computers though, and at least the Android devices are fully capable of running Linux just like the Pi. The only problem tends to be getting around the carrier or manufacturer restrictions like a locked bootloader or lack of root access. For [David]’s first try getting this to work, he tried to install Navidrome on a Samsung phone but had difficulties with the lack of memory and had to build the software somewhere else and then load it on the phone. It did work, but the stock operating system kept killing the process for consuming too much memory.

Without root access, [David] decided to try LineageOS, a version of Android which, among other benefits, is typically much more configurable than the stock version of Android that is shipped with smartphones. This allowed him to disable or uninstall anything not needed for his music server to free up enough memory. After some issues with transcoding the actual music files he planned on streaming, his music server was successfully up and running on a phone that would have otherwise been relegated to the junk drawer. The specific steps he took to get this working can be found on his GitHub page as well.

[David] also mentioned looking at PostmarketOS for this job which is certainly a viable option for some, but the Linux distribution for phones is only supported on a few devices. Another viable alternative for a project like this if no Raspberry Pis are available might be any of a number of Pine64 devices that might also be sitting around gathering dust, like the versatile Linux-based Pinephone.

Audio Old And New Meet In Perfect Harmony

There’s an uneasy meeting in the world of audio between digital and analogue. Traditional analogue audio reached a level of very high quality, but as old-style media-based audio sources have fallen out of favor there’s a need to replace them with ones that reflect a new digital audio world. To do this there are several options involving all-in-one Hi-Fi separates at a hefty price, a cheaper range of dongles and boxes for each digital input, or to do what [Keri Szafir] has done and build that all-in-one box for yourself.

The result is a 1U 19″ rack unit that contains an Orange Pi for connectivity and streaming, a hard drive to give it audio NAS capability, plus power switching circuitry to bring all the older equipment under automation. Good quality audio is dealt with by using a Behringer USB audio card, on which in a demonstration of how even some digital audio is now becoming outdated, she ignores the TOSlink connector.

The rear panel has all the connectors for power, USB, network, and audio laid out, while the front has an array of status lights and switches. We particularly like the hand-written lettering, which complements this as a homebrew unit. It certainly makes the Bluetooth dongle dangling at the back of our amplifier seem strangely inadequate.

If audio is your thing, we had a look at some fundamentals of digital audio as part of our Know Audio series.

GB Interceptor Enables Live Screen Capture From Game Boy

[Sebastian] had a tricky problem to solve. Competitors in a Tetris tournament needed to stream video of their Game Boy screens, but no solution readily existed. For reasons of fairness, emulators were right out, and no modifications could be made to the Game Boys, either. Thus, [Sebastian] created the GB Interceptor, a Game Boy capture cartridge.

Thanks to the design of the Game Boy, there’s plenty of access to useful signals via the cartridge port itself. [Sebastian] realized that a non-invasive capture device could be built to sit in-between the Game Boy and a cart, and send video to a computer. Unfortunately, there’s no direct access to the video RAM via this port, but [Sebastian] figured out a nifty workaround.

The build uses a Raspberry Pi Pico. The chip’s two cores emulate the Game Boy’s CPU and Picture Processing Unit, respectively. Doing this, while having the chips keep up with what’s going on in the Game Boy, required overclocking the Pico to 225 MHz. The system works by capturing data from the cartridge’s memory bus, and follows along with the instructions being run by the Game Boy. By doing this, the Pico is able to populate its own copy of the video RAM. It then spits this out over USB, where it can be displayed and streamed online as desired.

There are some edge-case limitations, but for its intended purpose, the system works great. Currently, the hardware is usable on Linux and Windows, though it does require some fiddling in the latter case. Files are on Github for those eager to build their own. If you simply want to dump carts rather than stream from your Game Boy, we can help there, too. Video after the break.

Continue reading “GB Interceptor Enables Live Screen Capture From Game Boy”

Livestreaming Backpack Takes Streaming On-The-Go

Anyone who’s anyone on the internet these days occasionally streams content online. Whether that’s the occasional livestream on YouTube or an every day video game session on Twitch, it’s definitely a trend that’s here to stay. If you want to take your streaming session on the go, though, you’ll need some specialized hardware like [Melissa] built into this livestreaming backpack.

[Melissa] isn’t actually much of a streamer but built this project just to see if it could be done. The backpack hosts a GoPro camera with a USB interface, mounted on one of the straps of the pack with some 3D printed parts, allowing it to act as a webcam. It is plugged into a Raspberry Pi which is set up inside the backpack, and includes a large heat sink to prevent it from overheating in its low-ventilation environment. There’s also a 4G modem included along with a USB battery pack to keep everything powered up.

The build doesn’t stop at compiling hardware inside a backpack, though. [Melissa] goes into detail on the project’s page about how to get all of the hardware to talk amongst themselves and where the livestream is setup as well. If you’d like a more permanently-located streaming setup with less expensive hardware, we have seen plenty of builds like this which will get the job done as well.

See How To Effectively Use A Green Screen In A Limited Space

Virtual green screens are pretty neat, but for results, nothing beats the real thing. But what if you have limited space? [Fred Emmott] had about 30 inches behind his desk to work with, and shares what it took to make a green screen work reliably in a limited space.

Even (and consistently deployable) lighting is even more important than the camera.

When it comes right down to it, the fundamentals of camera work (lighting, angles, and so on) are unchanged, but hanging a green screen only 30 inches behind one’s desk does make it a bit more challenging to dial in the right environment. In addition, [Fred] wanted a solution that could be deployed and packed away without much of a hassle, and without taking up too much storage space. He ended up using a collapsible green screen that can be pulled straight up and out from its container, similar to portable stand-up banners used at trade shows.

As for the camera end of things, [Fred] found that reliable, quality lighting was critically important, even more so than the camera used. For repeatable results, he suggests disabling any automatic features (such as low light enhancement, or auto white balance, and settings of that nature) and to use LED lighting in the ‘daylight’ range for illumination and fill. The key to good green screen results is to light things evenly, and this is a bit more challenging when working in such a tight space.

To deal with this, [Fred] suggests lights that can be easily repositioned, and put them as far back from things as you can. Get the lighting as even as possible, then adjust your software to match ([Fred] uses OBS Studio) for best results. Once that’s done, it can be more easily set up and torn down with minimal fiddling.

Computers sure make all this much easier than it was back in the day, and if you’re curious, here is all about how green screens were done before the digital age.

The Joy Of Broadcast Media Vs. The Paradox Of Choice

The rise of streaming services on the Internet was a revolutionary shift when it came to the world of media. No more would content be pumped in to homes in a one-way fashion, broadcast by major conglomerates and government-run organizations. Instead, individuals would be free to hunt for content suiting their own desires on an all-you-can-watch basis.

It’s led to a paradigm shift in the way we consume media. However, it’s also led to immense frustration thanks to the overwhelming amount of content on offer.  Let’s take a look at why that is, and some creative ways you can get around the problem.

The Paradox of Choice

Many find the masses of content on streaming services to be overwhelming to choose from. Credit: author screenshot

Traditionally, when it came to media, there were two major arms of delivery: broadcast, and home media. One might listen to the radio, or flick on the TV, or alternatively, spin up a record, or select a movie to watch on tape. If none of those options  sufficed, one might take a walk down to the local video store to rent something more appealing.

Fundamentally, it was an era in which choices were limited. There were a handful of TV stations to choose from, and if nothing good was on, you could go as far as finding something watchable on tape or going without. Many will remember afternoons and evenings spent watching reruns or a Friday night movie that had been on a million times before. Some shows went as far as becoming legends for their seemingly endless replay, from The Simpsons to M*A*S*H. 

As the Internet grew, though, the game started to change. Torrent websites and streaming services came along, offering up the sum total of the world’s cultural output for free, or for a nominal cost for those averse to piracy. Suddenly when it came to choosing a movie to watch, one wasn’t limited to the five or so films on at the local cinema, nor what was left on the shelves at the local video rental. Instead, virtually any movie, from the invention of the format, could be yours to watch at a moment’s notice.

With so many options on the table, many of us find it harder to choose. It’s an idea popularly known as the Paradox of Choice, a term popularized by US psychologist Barry Schwartz in 2004. When our options are limited to a select few, choice is easy. They can quickly be compared and ranked and an ideal option chosen.

Add thousands of choices to the pile, and the job escalates in complexity to the point of becoming overwhelming. With so many different choices to contrast and compare, finding the mythical right choice becomes practically impossible. Continue reading “The Joy Of Broadcast Media Vs. The Paradox Of Choice”