How Many LEDs Can You Drive?

February 18, 2020 by Bryan Cockfield 35 Comments

Driving more than a handful of LEDs from a microcontroller is often a feat that takes tedious wiring, tricking the processor, or a lot of extra external hardware. Charlieplexing is perhaps the most notorious of these methods, and checks two of those three boxes. This library for the Teensy 4.0 checks all three, but it can also drive a truly staggering 32,000 LEDs at one time.

The TriantaduoWS2811 library is able to drive 32 channels of LEDs from a Teensy 4.0 using only three pins and minimal processor resources. It uses the FlexIO and DMA subsystems of the i.MX RT1062, the particular ARM processor on the Teensy, to drive four external shift registers. Together, the system is able to achieve 30 frames per second on with 1,000 LEDs per channel, for a total of 32,000 LEDs. Whoah.

[Ward] aka [wramsdell] wondered what one would do with all of the horsepower of a Teensy microcontroller when he first saw its specifications, and was able to build this project to take advantage of its features. What’s surprising, though, is that it doesn’t use nearly everything the processor is capable of, so you can do other tasks at the same time as driving that giant LED display.

Micropython And C Play Together Better

August 31, 2019 by Bryan Cockfield 20 Comments

Python is a versatile, powerful language but sometimes it’s not the best choice, especially if you’re doing work in embedded systems with limited memory. Sometimes you can get away with MicroPython for these cases, but the best language is likely C or assembly. If you’re really stubborn, like [amirgon], and really want C and Python to play well together, you can make use of his new tool which can bring any C library to MicroPython.

As an example of how this tool is used, a “Pure MicroPython” display driver for ILI9341 on the ESP32, which means that everything was implemented in MicroPython. [amirgon] wanted to see how the Python driver would compare to one that’s already been written in C, and use it to showcase MicroPython binding. This tool also automatically converts structs, unions, enums and arrays to Python objects, and provides a means to work with pointers which is something that Python doesn’t handle in the same way that C requires.

[amirgon] hopes that this tool will encourage the adoption of Micropython by removing the obstacle of missing APIs and libraries in MicroPython. Since most libraries for systems like these are written in C, a way to implement them in Python is certainly powerful. We featured one use case for this a while back, but this is a much more generic fix for this coding obstacle.

Python And The Internet Of Things Hack Chat

April 1, 2019 by Dan Maloney 6 Comments

Join us Wednesday at noon Pacific time for the Python and the Internet of Things Hack Chat!

Opinions differ about what the most-used programming language in right now is, but it’s hard to deny both the popularity and versatility of Python. In the nearly 30 years since it was invented it has grown from niche language to full-blown development environment that seems to be everywhere these days. That includes our beloved microcontrollers now with MicroPython, and Adafruit’s CircuitPython, greatly lowering the bar for entry-level hackers and simplifying and speeding development for old hands and providing a path to a Python-powered Internet of Things.

The CircuitPython team from Adafruit Industries – Dan Halbert, Kattni Rembor, Limor “Ladyada” Fried, Phillip Torrone, and Scott Shawcroft – will drop by the Hack Chat to answer all your questions about Python and the IoT. Join us as we discuss:

How CircuitPython came to be;
The range of IoT products that support Python;
Getting started with Python on IoT devices; and
What’s on the horizon for a Python-powered IoT?

And as extra enticement, we’ll be giving away five free one-year passes to Adafruit.io! We’ll draw five names at random from the list of Hack Chat attendees. Stop by for a chance to win. And, the Adafruit team will be streaming video live during the Hack Chat as well.

You are, of course, encouraged to add your own questions to the discussion. You can do that by leaving a comment on the Python and the Internet of Things Hack Chat and we’ll put that in the queue for the Hack Chat discussion.

Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, April 3, at noon, Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

Want a quick peek at what’s possible with CircuitPython? Check out this PyPortal event countdown timer that just happens to be counting down the hours till the next Hack Chat.

Creating KiCad Parts From A PDF Automagically

October 5, 2018 by Brian Benchoff 20 Comments

For anyone out there who has ever struggled finding a part for Eagle or KiCad, there are some who would say you’re doing it wrong. You’re supposed to make your own parts if you can’t find them in the libraries you already have. This is really the only way; PCB design tools are tools, and so the story goes you’ll never be a master unless you can make your own parts.

That said, making schematic parts and footprints is a pain, and if there’s a tool to automate the process, we’d be happy to use it. That’s exactly what uConfig does. It automatically extracts pinout information from a PDF datasheet and turns it into a schematic symbol.

uConfig is an old project from [sebastien caux] that’s been resurrected and turned into an Open Source tool. It works by extracting blocks of text from a PDF, sorts out pin numbers and pin labels, and associates those by the relevant name to make pins. It’s available as a pre-built project (for Windows, even!), and works kind of like magic.

The video demo below shows uConfig importing a PDF datasheet — in this case a PIC32 — automatically extracting the packages from the datasheet, and turning that into a schematic symbol. It even looks as if it’ll work, too. Of course, this is just the schematic symbol, not the full part including a footprint, but when it comes to footprints we’re probably dealing with standard packages anyway. If you’re looking to build a software tool that takes a datasheet and spits out a complete part, footprint and all, this is the place to start.

Continue reading “Creating KiCad Parts From A PDF Automagically” →

Simplifying Basic LED Effects

June 13, 2018 by Al Williams 24 Comments

There was a time when having a blinking blue LED on a project was all you needed to be one of the cool kids. But now you need something more complex. LEDs should not just snap on, they should fade in and out. And blinking? Today’s hotness is breathing LEDs. If that’s the kind of project you want, you should check out [jandelgado’s] jled library.

At first glance, an Arduino library for LED control might seem superfluous, but if you are interested in nice effects, the coding for them can be a bit onerous. If you don’t mind stopping everything while you fade an LED on (or off) then sure, you just write a loop and it is a few lines of code. But if you want to have it happen while other things continue to execute, it is a little different. The library makes it very simple and it is also nicely documented.

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More Blinky = More Better – The WS2812FX Library

December 12, 2016 by Lewin Day 16 Comments

The WS2812 is an amazing piece of technology. 30 years ago, high brightness LEDs didn’t even exist yet. Now, you can score RGB LEDs that even take all the hard work out of controlling and addressing them! But as ever, we can do better.

Riffing on the ever popular Adafruit NeoPixel library, [Harm] created the WS2812FX library. The library has a whole laundry list of effects to run on your blinkenlights – from the exciting Hyper Sparkle to the calming Breathe inspired by Apple devices. The fantastic thing about this library is that it can greatly shorten development time of your garden-variety blinkables – hook up your WS2812s, pick your effect, and you’re done.

[Harm]’s gone and done the hard yards, porting this to a bevy of platforms – testing it on the Arduino Nano, Uno, Micro and ESP8266. As a proof of concept, they’ve also put together a great demonstration of the software – building some cute and stylish Christmas decorations from wood, aluminium, and hacked up Christmas light housings. Combining it with an ESP8266 & an app, the effects can be controlled from a smartphone over WiFi. The assembly video on YouTube shows the build process, using screws and nails to create an attractive frame using aluminium sheet.

This project is a great example of how libraries and modern hardware allow us to stand on the shoulders of giants. It’s quicker than ever to build amazingly capable projects with more LEDs than ever. Over the years we’ve seen plenty great WS2812 projects, like this sunrise alarm clock or this portable rave staff.
As always, blink hard, or go home. Video after the break.

Continue reading “More Blinky = More Better – The WS2812FX Library” →

Hackaday Prize Entry: Magic Bit-Of-Wire Motion Detector Library For Arduino

September 1, 2016 by Gerrit Coetzee 11 Comments

We’re still not sure exactly how [connornishijima]’s motion detector works, though many readers offered plausible explanations in the comments the last time we covered it. It works well enough, though, and he’s gone and doubled down on the Arduino way and bundled it up nicely into a library.

In the previous article we covered [connor] demonstrating the motion detector. Something about the way the ADC circuit for the Arduino is wired up makes it work. The least likely theory so far involves life force, or more specifically, the Force… from Star Wars. The most likely theories are arguing between capacitance and electrostatic charge.

Either way, it was reliable enough a phenomenon that he put the promised time in and wrote a library. There’s even documentation on the GitHub. To initialize the library simply tell it which analog pin is hooked up, what the local AC frequency is (so its noise can be filtered out), and a final value that tells the Arduino how long to average values before reporting an event.

It seems to work well and might be fun to play with or wow the younger hackers in your life with your wizarding magics.