A Simple Web-Based Wiring Harness Tool

When building electronic assemblies there is quite often the need to construct custom cables to hook things up. It’s all very well if you’re prototyping by hand, or just building one or two of a thing, but if you’re cranking them out using outside help, then you’re going to want to ensure that cable is described very accurately. [Christian Nimako-Boateng Jr.] presents for us the first version of wirely, a wiring harness tool. This is a web-based tool that allows one to describe the cable ends and connectivity between them, producing a handy graphic and exports to excel in a format that should be easy to follow.

Based around the wireviz Python library running on a flask-based backend, image data are sent to the web assembly front-end and rendered with OpenGL. Configuration files can be imported and exported as JSON, making it easily linkable to other tools if required. Helpfully, the tool also seems to support some kind of revision control, although we didn’t try that yet. The process is straightforward enough, one simply defines a few groups (these relate to individual PCBs or other floating items in the assembly) which each contain one or more connectors. First, the connectors are described with part numbers, and wire gauge data, before defining the list of connections (wires) showing which signal and physical pins are connected together. Nothing more complex than that yet. We think there is still some more functionality that the tool could manage, such as shielding and guarding details, twisted pair definitions and a few others, but for a first pass, wirely looks pretty handy.

If you want a more heavyweight option using IEC 60617 symbols for describing wiring harnesses, then look no farther than QElectroTech, and yes, we have covered wireviz before, just for those that want to cut out the middleman and describe their cables in Python directly.

Python Web Proxy Convinces Sonos To Stream YouTube

[Maurice-Michel Didelot] owns a Sonos smart speaker, and was lamenting the devices inability (or plain unwillingness) to stream music from online sources without using a subscription service. YouTube Music will work, but being a subscription product there is a monthly fee, which sucks since you can listen to plenty of content on YouTube for free. [Maurice] decided that the way forward was to dig into how the Sonos firmware accesses ‘web radio’ sources, and see if that could be leveraged to stream audio from YouTube via some kind of on-the-fly stream conversion process.

What? No MP4 support for web radio? Curses!

So let’s dig in to how [Maurice] chose to approach this. The smart speaker can be configured to add various streaming audio sources, and allows you add custom sources for those. The Sonos firmware supports a variety of audio codecs, besides MP3, but YouTube uses the MP4 format. Sonos won’t handle that from a web radio source, so what was there to do, but make a custom converter?

After a little digging, it was determined that Sonos supports AAC encoding (which is how MP4 encodes audio) but needs it wrapped in an ADTS (Audio Data Transport Stream) container. By building a reverse web-proxy application, in python using Flask, it was straightforward enough to grab the YouTube video ID from the web radio request, forward a request to YouTube using a modified version of pytube tweaked to not download the video, but stream it. Pytube enabled [Maurice] to extract the AAC audio ‘atoms’ from the MP4 container, and then wrap them up with ADTS and forward them onto the Sonos device, which happily thinks it’s just a plain old MP3 radio stream, even if it isn’t.

Sonos doesn’t have the best reputation, let’s say, but you can’t deny that there’s some pretty slick tech going on inside. Here’s a neat hack we covered last year, adding Sonos support to an old school speaker, and a nice teardown of a IKEA Sonos-compatible unit, which uses some neat design hacks.

Thanks [mip] for the tip!

Featured image by Charles Deluvio on Unsplash.

Espresso maker with added nixie flair

AI Powered Coffee Maker Knows A Bit Too Much About You

People keep warning that Skynet and the great robot uprising is not that far away, what with all this recent AI and machine-learning malarky getting all the attention lately. But we think going straight for a terminator robot army is not a very smart approach, not least due to a lack of subtlety. We think that it’s a much better bet to take over the world one home appliance at a time, and this AI Powered coffee maker might just well be part of that master plan.

Raspberry Pi Zero sitting atop the custom nixie tube driver PCB
PCB stackup with Pi Zero sat atop the driver / PSU PCBs

[Mark Smith] has taken a standard semi-auto espresso maker and jazzed it up a bit, with a sweet bar graph nixie tube the only obvious addition, at least from the front of the unit. Inside, a Raspberry Pi Zero sits atop his own nixie tube hat and associated power supply. The whole assembly is dropped into a 3D printed case and lives snuggled up to the water pump.

The Pi is running a web application written with the excellent Flask framework, and also an additional control application written in python. This allows the user to connect to the machine via Ethernet and see its status. The smarts are in the form of a simple self-grading machine learning algorithm, that takes a time series as an input (in this case when you take your shots of espresso) and after a few weeks of data, is able to make a reasonable prediction as to when you might want it in the future. It then automatically heats up in time for you to use the machine, when you usually do, then cools back down to save energy. No more pointless wandering around to see if the machine is hot enough yet – as you can just check the web page and see from the comfort of your desk.

But that’s not all [Mark] has done. He also improved the temperature control of the water boiler, and added an interlock that prevents the machine from producing a shot until the water temperature is just so. Water level is indicated by the glorious bar graph nixie tube, which also serves a few other user indication duties when appropriate. All in all a pretty sweet build, but we do add a word of caution: If your toaster starts making an unreasonable number of offers of toasted teacakes, give it a wide berth.

Continuous Integration: What It Is And Why You Need It

If you write software, chances are you’ve come across Continuous Integration, or CI. You might never have heard of it – but you wonder what all the ticks, badges and mysterious status icons are on open-source repositories you find online. You might hear friends waxing lyrical about the merits of CI, or grumbling about how their pipeline has broken again.

Want to know what all the fuss is about? This article will explain the basic concepts of CI, but will focus on an example, since that’s the best way to understand it. Let’s dive in. Continue reading “Continuous Integration: What It Is And Why You Need It”

Making An Update Server For PythonAnywhere And GitHub

Cloud based IDEs and development tools have grown over the years, though most have limitations in their free tiers and may not be fully compatible with other services such as GitHub. [Aadi Bajpai] loved using PythonAnywhere and to collaborate using GitHub, so he made a update server that automatically updates the running code once you make a push to Github

PythonAnywhere gives you access to a python shell over a web browser, and also lets you run a web app that can be accessed via a custom sub-domain. Even though it does not have direct integration with GitHub, you can drop to the bash shell to and get access to a git client.

For this hack, [Aadi Bajpai] utilizes the webhooks from GitHub that are triggered when a push event is detected. A flask server running on PythonAnywhere is written such that once triggered by the get POST request, it locally executes a git pull from the repository. There a bit more work that allows adding a bit of security sauce to the recipe but it is a pretty elegant solution and can be used for other cases as well.

Setting up alert notifications has been demonstrated to be an interesting task, though integrating Discord or Slack for notifications adds a little more bragging rights.

Yes, You Can Put IoT On The Blockchain Using Python And The ESP8266

Last year, we saw quite a bit of media attention paid to blockchain startups. They raised money from the public, then most of them vanished without a trace (or product). Ethics and legality of their fundraising model aside, a few of the ideas they presented might be worth revisiting one day.

One idea in particular that I’ve struggled with is the synthesis of IoT and blockchain technology. Usually when presented with a product or technology, I can comprehend how and/or why someone would use it – in this case I understand neither, and it’s been nagging at me from some quiet but irrepressible corner of my mind.

The typical IoT networks I’ve seen collect data using cheap and low-power devices, and transmit it to a central service without more effort spent on security than needed (and sometimes much less). On the other hand, blockchains tend to be an expensive way to store data, require a fair amount of local storage and processing power to fully interact with them, and generally involve the careful use of public-private key encryption.

I can see some edge cases where it would be useful, for example securely setting the state of some large network of state machines – sort of like a more complex version of this system that controls a single LED via Ethereum smart contract.

What I believe isn’t important though, perhaps I just lack imagination – so lets build it anyway.

Continue reading “Yes, You Can Put IoT On The Blockchain Using Python And The ESP8266”

Control Anything With A Chat Bot

In the world of Internet of Things, it’s easy enough to get something connected to the Internet. But what should you use to communicate with and control it? There are many standards and tools available, but the best choice is always to use the tools you have on hand. [Victor] found himself in this situation, and found that the best way to control an Internet-connected car was to use the Flask server he already had.

The remote controlled car was originally supposed to come with an Arduino, but the microcontroller was missing upon arrival. He had a Raspberry Pi around, and was able to set that up to replace the Arduino. He also took the opportunity to use the expanded functionality of the Pi compared to the Arduino and wrote a Flask server to control it, which is accessed as if you are communicating with a chat bot. Sending the words “go left/forward” to the Flask server will control the car accordingly, for example.

The chat bot itself contains some gems as well, and would be useful for any project that makes use of regular expressions. It also seems to be easily expandable. The project also uses voice commands, and does so by making extensive use of Mozilla’s voice recognition suite. If you want to get deep in the weeds of voice recognition on your own though, you can also explore TensorFlow at your leisure.