websockets

13 Articles

Squish That Stack With Rampart

November 24, 2022 by 18 Comments

[P B Richards] and [Aaron Flin] were bemoaning the resource hunger of modern JavaScript environments and planned to produce a system that was much stingier with memory and CPU, that would fit better on lower-end platforms. Think Nginx, NodeJS, and your flavour of database and how much resource that all needs to run properly. Now try wedge that lot onto a Raspberry Pi Zero. Well, they did, creating Rampart: a JavaScript-based complete stack development environment.

The usual web applications have lots of tricks to optimise for speed, but according to the developers, Rampart is still pretty fast. Its reason for existence is purely about resource usage, and looking at a screen grab, the Rampart HTTP server weighs in at less than 10 MB of RAM. It appears to support a decent slew of technologies, such as HTTPS, WebSockets, SQL search, REDIS, as well as various utility and OS functions, so shouldn’t be so lightweight as to make developing non-trivial applications too much work. One interesting point they make is that in making Rampart so frugal when deployed onto modern server farms it could be rather efficient. Anyway, it may be worth a look if you have a reasonable application to wedge onto a small platform.

We’ve seen many JavaScript runtimes over the years, like this recent effort, but there’s always room for one more.

Dial-Up Internet Over WhatsApp

November 13, 2022 by 42 Comments

As we returned from Supercon 2022, we noticed many airlines offer free in-flight messaging. While the messages are handy for complaining about the seat size, it isn’t quite as exciting as access to the internet. In the air, we wondered how hard it would be to tunnel an internet connection over messaging. Funny enough, [Aleix Rodríguez Alameda] has a project that does exactly that by tunneling traffic over Whatsapp.

In [Aleix]’s case, cell carriers are pretty stingy with internet data when traveling in South America but often give unlimited WhatsApp data. So, ahead of time, two accounts are set up. A server is on one account and acts as a proxy to the broader internet and listens to messages to the server account. Then when in a restricted access setting, the client connects with a WebSocket and sends messages. The real trick for turning the WhatsApp messages into an internet connection the client can use is exposing a port from a local nodeJS web server. It connects to the WhatsApp API through a WebSocket and then acts as a proxy. Then, you set up traffic to be redirected through that port with curl or Firefox.

Packets are split to prevent you from sending too many messages, as in their testing, [Aleix]’s accounts were banned quickly. You shouldn’t expect massively fast speeds, as 300kbps was pretty typical during testing, which according to Wikipedia, is about what dial-up got with V.44 compression.

Which is around the same speed as TCP/IP tunneled over NRF23L01 radios.

3D Printering: Adding A Web Interface Where There Was None Before

December 31, 2021 by 8 Comments

[Renzo Mischianti] got himself a Chinese 3D printer, specifically a FlyingBear Ghost 5. (Cracking name, huh?) He was more than a little irritated with the fact that whilst the controller, an MKS Robin Nano, did have a integrated Wi-FI module, it provided no browser-based interface for monitoring and control purposes. This seemed a bit short-sighted in this day and age, to say the least. Not being at all happy with that situation, [Renzo] proceeded to write dedicated Wi-Fi firmware using websockets, but not without fully documenting his journey in a detailed series of the blog posts.

The resulting BeePrint web interface supports all the usual functions you would expect when managing a printer, everything from monitoring warm-up at the prep stage, to keeping tabs on the potential spaghetti monster via the connected IP camera. All good stuff. [Renzo] used an ESP32-cam, which is a low-cost 2 MP unit from our friends at Olimex, but we suspect it wouldn’t vastly difficult to add your own IP camera into the mix.

[Renzo] has a YT channel detailing quite a few other projects, which is definitely worth some viewing time in our opinion.

We’ve been covering 3D printer hacking since the dinosaurs were roaming. This is the oldest, and still one of the strangest, posts that we could find in a quick search. Anyone care to find something older?

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Arduino Enters The Cloud

February 7, 2019 by 61 Comments

Love it or hate it, for many people embedded systems means Arduino. Now Arduino is leveraging its more powerful MKR boards and introducing a cloud service, the Arduino IoT Cloud. The goal is to make it simple for Arduino programs to record data and control actions from the cloud.

The program is in beta and features a variety of both human and machine interaction styles. At the simple end, you can assemble a dashboard of controls and have the IoT Cloud generate your code and download it to your Arduino itself with no user programming required. More advanced users can use HTTP REST, MQTT, Javascript, Websockets, or a suite of command line tools.

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WebSockets Embedded With The ESP8266

October 3, 2018 by 15 Comments

It used to be that Web browsing was simple. You asked a server for some text, which was duly sent, and then formatted by your browser. Now a web page is as likely to be a full-blown application that is reading mail, editing text, or lots of other things and may use WebSockets to create a back channel to the server. Thanks to affordable hardware like the ESP8266 one of those things a modern web browser can do is sense and control the real world. [Acrobotic] has an interesting video about using WebSockets to allow a browser to talk to an ESP8266 web server in real time. You can see his simple demo in the video below.

Of course, you’ll use the usual language you use on the ESP8266 — [Acrobotic] uses C++ in the Arduino IDE. On the browser side you’ll use JavaScript, although that will be embedded in your C++ program which acts as a web server.

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