microcontroller

387 Articles

You Can Program AVRs From The Commodore 64

July 26, 2024 by 10 Comments

These days, most of our microcontroller boards come with bootloaders so you can squirt hex into them straight over USB. However, you don’t need to do things this way. If you’re more old school, you can program your AVRs right from a Commodore 64. [Linus Akesson] shows us how.

Programming an AVR isn’t that hard. By holding the chip in reset, it’s possible to flash code via a serial protocol using just three wires. However, that’s pretty impractical to do with modern PCs — they don’t come with addressable IO pins anymore. Normally, you’d use a dedicated programmer to do the job, but [Linus] found his had died on a Friday night. So he set about turning his C64 into one instead.

He decided to use the pins of the C64’s Joystick Port 2, with pins 1, 2, 3, and 4 hooked up to SCK, MOSI, Reset, and MISO on the AVR, respectively. 5 V and Ground were also provided courtesy of the C64’s port. He then whipped up a simple bit of assembly code to read a bit of AVR hex and spit it out over the Joystick port following the in-circuit programming protocol. With a 1541 Ultimate to load files on to the C64 in hand, it was easy to pull his compiled AVR program off his modern PC, chuck it on the C64, and then get the old Commodore to program the AVR in turn.

It’s not the first time [Linus] has wowed us with a C64 in hand. If you’ve got your own fresh projects for the best-selling computer of all time, don’t hesitate to let us know!

You Can Use LEDs As Sensors, Too

July 23, 2024 by 70 Comments

LEDs are a wonderful technology. You put in a little bit of power, and you get out a wonderful amount of light. They’re efficient, cheap, and plentiful. We use them for so much!

What you might not have known is that these humble components have a secret feature, one largely undocumented in the datasheets. You can use an LED as a light source, sure, but did you know you can use one as a sensor?

Continue reading “You Can Use LEDs As Sensors, Too” →

Time’s Up For Mbed

July 16, 2024 by 18 Comments

In a forum post has come the announcement that mBed, ARM’s accessible microcontroller development platform, is to reach end-of-life in July 2026. This means that the online platform and OS will no longer be supported by ARM, though the latter will remain an open source project. The website will be shuttered, and no new projects can be created after that date using ARM infrastructure.

mBed was originally launched back in 2009, as a competitor to the Arduino IDE for ARM’s chips. Its easy development made it attractive and there were soon an array of boards from different manufacturers supporting it, but perhaps due to its support for only the one architecture, it failed to find success. It’s certainly not the first time a single-architecture microcontroller development platform has been discontinued, we need only look to the Intel Edison for that, but given the success of ARM platforms in general it’s still something of a surprise. Perhaps it’s time to take the press release explanation that other platforms such as Arduino have simply been much more popular.

Will a community form around an open source mBed? Given that it’s been a definite minority among Hackaday projects over the years, while we hope it does, we’re not so sure.

mBed board image: Viswesr, CC BY-SA 3.0.

Embedded Python: MicroPython Is Amazing

July 11, 2024 by 105 Comments

In case you haven’t heard, about a month ago MicroPython has celebrated its 11th birthday. I was lucky that I was able to start hacking with it soon after pyboards have shipped – the first tech talk I remember giving was about MicroPython, and that talk was how I got into the hackerspace I subsequently spent years in. Since then, MicroPython been a staple in my projects, workshops, and hacking forays.

If you’re friends with Python or you’re willing to learn, you might just enjoy it a lot too. What’s more, MicroPython is an invaluable addition to a hacker’s toolkit, and I’d like to show you why. Continue reading “Embedded Python: MicroPython Is Amazing” →

A System Board For The 8008

May 27, 2024 by 27 Comments

Intel processors, at least for PCs, are ubiquitous and have been for decades. Even beyond the chips specifically built by Intel, other companies have used their instruction set to build chips, including AMD and VIA, for nearly as long. They’re so common the shorthand “x86” is used for most of these processors, after Intel’s convention of naming their processors with an “-86” suffix since the 1970s. Not all of their processors share this convention, though, but you’ll have to go even further back in time to find one. [Mark] has brought one into the modern age and is showing off his system board for this 8008 processor.

The 8008 predates any x86 processor by about six years and was among the first mass-produced 8-bit processors even before the well-known 8080. The expansion from four bits to eight was massive for the time and allowed a much wider range of applications for embedded systems and early personal computers. [Mark] goes into some of the details for programming these antique processors before demonstrating his system board. It gets power from a USB-C connection and uses a set of regulators and level shifters to make sure the voltages all match. Support for all the functions the 8008 needs is courtesy of an STM32. That includes the system memory.

For those looking to develop something like this, [Mark] has also added his development tools to a separate GitHub page. Although it’s always a good idea for those interested in computer science to take a look at old processors like these, it’s not always the easiest path to get original hardware like this, which also carries the risk of letting smoke out of delicate components. A much easier route is to spin up an emulator like an 8086 IBM PC emulator on an ESP32. Want to see inside this old chip? Have a look.

Continue reading “A System Board For The 8008” →

Flute Now Included On List Of Human Interface Devices

April 24, 2024 by 17 Comments

For decades now, we’ve been able to quickly and reliably interface musical instruments to computers. These tools have generally made making and recording music much easier, but they’ve also opened up a number of other out-of-the-box ideas we might not otherwise see or even think about. For example, [Joren] recently built a human interface device that lets him control a computer’s cursor using a flute instead of the traditional mouse.

Rather than using a MIDI interface, [Joren] is using an RP2040 chip to listen to the flute, process the audio, and interpret that audio before finally sending relevant commands to control the computer’s mouse pointer. The chip is capable of acting as a mouse on its own, but it did have a problem performing floating point calculations to the audio. This was solved by converting these calculations into much faster fixed point calculations instead. With a processing improvement of around five orders of magnitude, this change allows the small microcontroller to perform all of the audio processing.

[Joren] also built a Chrome browser extension that lets a flute player move a virtual cursor of sorts (not the computer’s actual cursor) from within the browser, allowing those without physical hardware to try out their flute-to-mouse skills. If you prefer your human interface device to be larger, louder, and more trombone-shaped we also have a trombone-based HID for those who play the game Trombone Champ.

Garage Door Automation With No Extra Hardware

April 11, 2024 by 10 Comments

Home automation projects have been popular as long as microcontrollers have been available to the general public. Building computers to handle minutiae so we don’t have to is one of life’s great joys. Among the more popular is adding some sort of system to a garage door. Besides adding Internet-connected remote control to the action of opening and closing, it’s also helpful to have an indicator of the garage door state for peace-of-mind. Most add some sensors and other hardware to accomplish this task but this project doesn’t use any extra sensors or wiring at all.

In fact, the only thing added to the garage door for this build besides some wiring is the microcontroller itself. After getting the cover of the opener off, which took some effort, a Shelly Uni was added and powered by the 12V supply from the opener itself. The garage door opener, perhaps unsurprisingly, has its own way of detecting when the door is fully open or closed, so some additional wire was added to these sensors to let the microcontroller know the current state. Shelly Uni platforms have a WiFi module included as well, so nothing else was needed for this to function as a complete garage door automation platform.

[Stephen] uses Home Assistant as the basis for his home automation, and he includes all of the code for getting this platform up and running there. It wouldn’t be too hard to get it running on other openers or even on other microcontroller platforms; the real key to this build is to recognize that sometimes it’s not necessary to reinvent the wheel with extra sensors, limit switches, or even power supplies when it’s possible to find those already in the hardware you’re modifying. This isn’t always possible, though, especially with more modern devices that might already be Internet-connected but probably don’t have great security.