#embedded-programming

[adafruit]

OPT4048 - a "tri-stimulus" light sensor 🔴🟢🔵

We were chatting in the forums with someone when the OPT4048 (https://www.digikey.com/en/products/detail/texas-instruments/OPT4048DTSR/21298553) came up. It's an interesting light sensor that does color sensing but with diodes matched to the CIE XYZ color space. This would make them particularly good for color-light tuning. We made a cute breakout for this board. Fun fact: it's 3.3V power but 5V logic friendly.

[allie-leth]

I made an output agnostic logging framework for embedded devices that would work on anything as it's written only with standard C++ libs. In theory I could use it for linux or pis, lol. I made it because I kept having to write new handlers for serial, mqtt, uart, then having to like wire them all together without creating dependency loops or other issues - especially because I often work on meshes or online embedded devices that require multiple outputs. Now you just write your handler, tell it what tags to watch, and it'll log according to tag and log level. So you could write a serial debugging log handler when you're first making it. Then when you're done, disable it, and it'll stop outputting - but then later assign the serial debugging log tag to your MQTT handler and get all your debugging serial lines output to MQTT - then just disable it again when you're done. There's still some polish I need to put into it, it has some jank, some bugs, but it's working and neat. it's kind of neat.

[youboirusty]

If you fuck up in JS you get a dumb "couldn't read property of undefined".

If you fuck up in Cpp you get a cool glitch effect from reading bad sections of your memory for free!

[ocki-crafts]

I couldn't find my little ring stitch counter thing so I threw this together

Only after did I realize it would have been easier to just write something for my computer, but this is definitely cooler looking

[bitstream24]

CAN Bus Development for Embedded Systems: With and Without an Operating System

Explore the differences in CAN Bus development between embedded systems with or without an operating system. Compare Linux-based Raspberry Pi with PiCAN HATs to bare-metal Teensy and ESP32 platforms. Learn which solution fits your application needs.

[0x4468c7a6a728]

i've gotta program something soon...

[i-wanna-b-yours]

SOMEONE GIVE ME A BLOODY INTERNSHIP 😭

[immortalsins]

this report is about to be the worst work of my degree thus far

[drawthethingdoppelganger]

I'm in too deep to get out (college)

[watchmorecinema]

Normally I just post about movies but I'm a software engineer by trade so I've got opinions on programming too.

Apparently it's a month of code or something because my dash is filled with people trying to learn Python. And that's great, because Python is a good language with a lot of support and job opportunities. I've just got some scattered thoughts that I thought I'd write down.

Python abstracts a number of useful concepts. It makes it easier to use, but it also means that if you don't understand the concepts then things might go wrong in ways you didn't expect. Memory management and pointer logic is so damn annoying, but you need to understand them. I learned these concepts by learning C++, hopefully there's an easier way these days.

Data structures and algorithms are the bread and butter of any real work (and they're pretty much all that come up in interviews) and they're language agnostic. If you don't know how to traverse a linked list, how to use recursion, what a hash map is for, etc. then you don't really know how to program. You'll pretty much never need to implement any of them from scratch, but you should know when to use them; think of them like building blocks in a Lego set.

Learning a new language is a hell of a lot easier after your first one. Going from Python to Java is mostly just syntax differences. Even "harder" languages like C++ mostly just mean more boilerplate while doing the same things. Learning a new spoken language in is hard, but learning a new programming language is generally closer to learning some new slang or a new accent. Lists in Python are called Vectors in C++, just like how french fries are called chips in London. If you know all the underlying concepts that are common to most programming languages then it's not a huge jump to a new one, at least if you're only doing all the most common stuff. (You will get tripped up by some of the minor differences though. Popping an item off of a stack in Python returns the element, but in Java it returns nothing. You have to read it with Top first. Definitely had a program fail due to that issue).

The above is not true for new paradigms. Python, C++ and Java are all iterative languages. You move to something functional like Haskell and you need a completely different way of thinking. Javascript (not in any way related to Java) has callbacks and I still don't quite have a good handle on them. Hardware languages like VHDL are all synchronous; every line of code in a program runs at the same time! That's a new way of thinking.

Python is stereotyped as a scripting language good only for glue programming or prototypes. It's excellent at those, but I've worked at a number of (successful) startups that all were Python on the backend. Python is robust enough and fast enough to be used for basically anything at this point, except maybe for embedded programming. If you do need the fastest speed possible then you can still drop in some raw C++ for the places you need it (one place I worked at had one very important piece of code in C++ because even milliseconds mattered there, but everything else was Python). The speed differences between Python and C++ are so much smaller these days that you only need them at the scale of the really big companies. It makes sense for Google to use C++ (and they use their own version of it to boot), but any company with less than 100 engineers is probably better off with Python in almost all cases. Honestly thought the best programming language is the one you like, and the one that you're good at.

Design patterns mostly don't matter. They really were only created to make up for language failures of C++; in the original design patterns book 17 of the 23 patterns were just core features of other contemporary languages like LISP. C++ was just really popular while also being kinda bad, so they were necessary. I don't think I've ever once thought about consciously using a design pattern since even before I graduated. Object oriented design is mostly in the same place. You'll use classes because it's a useful way to structure things but multiple inheritance and polymorphism and all the other terms you've learned really don't come into play too often and when they do you use the simplest possible form of them. Code should be simple and easy to understand so make it as simple as possible. As far as inheritance the most I'm willing to do is to have a class with abstract functions (i.e. classes where some functions are empty but are expected to be filled out by the child class) but even then there are usually good alternatives to this.

Related to the above: simple is best. Simple is elegant. If you solve a problem with 4000 lines of code using a bunch of esoteric data structures and language quirks, but someone else did it in 10 then I'll pick the 10. On the other hand a one liner function that requires a lot of unpacking, like a Python function with a bunch of nested lambdas, might be easier to read if you split it up a bit more. Time to read and understand the code is the most important metric, more important than runtime or memory use. You can optimize for the other two later if you have to, but simple has to prevail for the first pass otherwise it's going to be hard for other people to understand. In fact, it'll be hard for you to understand too when you come back to it 3 months later without any context.

Note that I've cut a few things for simplicity. For example: VHDL doesn't quite require every line to run at the same time, but it's still a major paradigm of the language that isn't present in most other languages.

Ok that was a lot to read. I guess I have more to say about programming than I thought. But the core ideas are: Python is pretty good, other languages don't need to be scary, learn your data structures and algorithms and above all keep your code simple and clean.

[adafruit]

Solenoids go clicky-clacky 🔩🔊🤖

We're testing out an I2C-to-solenoid driver today. It uses an MCP23017 expander. We like this particular chip for this usage because it has push-pull outputs, making it ideal for driving our N-channel FETs and flyback diodes. The A port connects to the 8 drivers, while the B port remains available for other GPIO purposes. For this demo, whenever we 'touch' a pin on port B to ground, the corresponding solenoid triggers provide an easy way to check speed and power usage.

[allie-leth]

My worker firmware works! It flashed itself over, now just to add some roll back, security, and validation features. But effectively this means I never have to plug in another ESP32 to send them firmware. I can just tell them to post to MQTT from the worker firmware for logging and post the firmware binary to my local file server. This makes my life so much easier while building out this mesh of meshes multi-protocol com lib. Hell yeahhh

[youboirusty]

The voices won again. Over a week of my life into an impulse project. A game console that only has one knob, one colour and one game.

Aside from the fact that using one of two input methods on the console puts you at a disadvantage, at the very least it's a cool icebreaker.

Everything runs directly on the device, there's a Pi Pico microcontroller driving an OLED panel. The crate I used for drawing sprites also provides web simulator outputs, so the game's also on itch! Touch input is still on the roadmap.

[just-my-insufferable-existance]

Should I actually make meaningful posts? Like maybe a few series of computer science related topics?

I would have to contemplate format, but I would take suggestions for topics, try and compile learning resources, subtopics to learn and practice problems

[bitstream24]

Discover the Basics of the Raspberry Pi Along with Multiple Projects

The Raspberry Pi has become incredibly popular among computer hobbyists and businesses for a variety of reasons. It consumes very little power, is portable, has solid-state storage, makes no noise, and offers extension capabilities, all at a very low price.