ARM Programming By Example

The ARM processor is popping up everywhere. From Raspberry Pis, to phones, to Blue Pill Arduino-like boards, you don’t have to go far to find an ARM processor these days. If you program in C, you probably don’t care much or even think about it. But do you know ARM assembly language? Well, if you look at it one way, it can’t be too hard. The CPU only has about 30 distinct operations — that’s why it is called RISC. Of course, sometimes fewer instructions actually make things more difficult. But you can get a great starting tutorial with the 21 programs on the ARM Assembly by Example website.

You need a 32-bit ARMv6 or better — so Raspberry Pi will work here. The compiler, of course, is gcc and all the associated tools. if you have the right hardware, there are sections on using the floating point unit and the NEON co-processor, too.

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Dumping An EMMC Chip With Many Bodge Wires

Sometimes, you know where the data you need is stored, you just don’t have a way to access it. In this case, [GetHypoxic] needed to rip data off an eMMC chip, salvaged out of a camera. With no desire to wait for an adapter to show up, it was time to bust out the bodge!

Once removed from the PCB, bodge wires were attached to the ball-grid array contacts on the bottom of the chip. Incredibly fine soldering was the order of the day to get these hooked up to the tiny pads, and we count 11 or 12 bodge wires in total. 1.8 volts was manually supplied to the eMMC chip, and it was directly wired up to the contacts of a built-in card reader out of an old laptop for reading.

Despite the rats-nest look of it all, and the yellow polyimide tape holding it together, [GetHypoxic] reported that it mounted successfully and got the job done. We’ve seen similar hacks before, too, wiring eMMC chips up to SD card adapters. It might look messy, but hey – it sure beats waiting for shipping!

An acrylic map of the state of Lagos. Each region is lit a different color by LEDs shining on the acrylic panels. The colors coorespond to the air quality index key which is lit in cooresponding colors to the value.

Hackaday Prize 2022: This Interactive Air Quality Map Makes The Invisible Visible

Air quality can have a big impact on your health, but it isn’t always something you can see. [Ahmed Oyenuga] wanted to make air quality something more tangible and developed an Interactive Air Quality Map.

Using addressable LEDs and acrylic panels, [Oyenuga]’s map lights up different regions of his state (Lagos) with colors that correspond to qualitative values of the air quality readings. The color key on the edge of the map becomes a readout when you touch a specific region of the map.

Most of the map’s functionality is handled by an Arduino WiFi 1010, but the capacitive touch is running on a custom board [Oyenuga] designed with an ATSAMD21J17. [Oyenuga] is getting air quality data via a DesignSpark Environmental Sensor Development Kit (ESDK) and then uses reverse geocoding to take the GPS data and turn it into a location the map will understand.

If you’re interested in different options for monitoring air quality that could feed into a map like this, why don’t you check out this LoRa Air Quality Monitor or even a Mobile Air Quality Monitor.

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2022 Supercon: More Talks, More Speakers!

Round two of the 2022 Supercon talks is out, and it’s another superb lineup. This round is full of high voltage, art, and science. If you’ve ever dreamed of starting up your own hacker company, making your own refrigerator, teaching your toaster to think, or just making your breath glow, then Supercon is where you want to be Nov. 4-6!

Supercon will sell out, so get your tickets now before it’s too late. And stay tuned for the next and final round of talk reveals next week! Plus the keynote speaker reveal. Plus workshops. Oh my. Continue reading “2022 Supercon: More Talks, More Speakers!”

A Cassette Interface For A 6502 Breadboard Computer, Kansas City-Style

It’s been a long time since computer hobbyists stored their programs and data on cassette tapes. But because floppy drives were expensive peripherals and hard drives were still a long way from being the commodity they are today, cassettes enjoyed a long run at the top of the bulk data storage heap.

Celebrating that success by exploring the technology of cassette data storage is the idea behind [Greg Strike]’s Kansas City decoder project, which he hopes to use with his [Ben Eater]-style 6502 computer. The video below explains the Kansas City standard in some detail, and includes some interesting historical context we really hadn’t delved into before. There are also some good technical details on the modulation scheme KCS used, which [Greg] used to base his build. After a failed attempt to use an LM567 tone decoder chip, he stumbled upon [matseng]’s KCSViewer project, which decodes KCS-encoded audio signals using nothing but discrete components.

[Greg]’s prototype has a comparator to convert sine waves to square waves, followed by pair of monostable timers, each tuned to either the high or low frequency defined in the KCS specs. A test signal created using Audacity — is there anything it can’t do? — was successfully decoded, providing proof of concept for the project’s first phase. We’re looking forward to the rest of the series, which will turn this into an actual decoder, and presumably add an encoder as well.

Listeners of the Hackaday Podcast may recall we experimented with using KCS to hide some data within an episode a few months back.

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front and back of the Jolly Wrencher SAO

Jolly Wrencher SAO, And How KiCad 6 Made It Easy

If you plan to attend Supercon or some other hacker conference, know that you’re going to get a badge with a SAO (Simple Add-On) connector, a 4-pin or 6-pin connector that you can plug an addon board onto. There’s myriads of SAOs to choose from, and if you ever felt like your choice paralysis wasn’t intense enough, now you have the option of getting a Jolly Wrencher SAO board!

This board gives you an SMD prototyping space, with 1.27mm (0.05″ pitch) pads, suitable for many passive components, ICs and even modules like the ESP32 WROOM. Those pads are diagonally interspersed with ground-fill-connected pads – if you want to bodge something on the spot, you don’t need to pull separate GND wires. Given the Supercon badge specifics, the SAO-standard SDA and SCL pins have RX and TX labels as well. For bonus points, the eyes are transparent, with LED footprints behind them – it’s my first time designing a PCB where the LED shines through the FR4, and I hope that the aesthetics work out!

This design is open with gerber files available for download, so if you thought of making a quick PCB order, I’m giving you one more .zip file to add to it. Otherwise, it’s possible that you will find a Wrencher board lying around at Supercon! Now, I’d like to tell you how KiCad 6 made it super easy to design this PCB – after all, there’s never enough SAOs, and it’s quite likely you’ll want to design your own special SAO, too.

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Don’t Miss The Philadelphia Maker Faire This Weekend

For readers in the American Northeast that are looking for something to do this weekend, may we humbly suggest a day trip to attend the 2022 Philadelphia Maker Faire on Saturday, October 15th. After taking the last two years off due to COVID-19, the event has moved to the Independence Seaport Museum for its grand return, and is sure to attract plenty of hackers and makers who are eager to show off their pandemic projects.

Of course, the nature of these events is that you never really know what you’re going to see until you actually get there. But just browsing the list of confirmed projects that will have dedicated tables set up, we can tell there’s some very interesting stuff on tap — from fighting robots and hologram printers, to plasma physics and electric hydrofoils. While the deadline to submit projects for official inclusion has long since passed, we can tell you from experience that’s not going to stop folks from showing up with their own gadgets to show off to the captive audience. Especially if they’re of the wearable variety; it’s not really a Maker Faire unless somebody is wearing something that’s blinking.

Olympia and Becuna

Naturally the Faire itself is obviously the main event, but don’t forget that the Independence Seaport Museum itself is worth checking out while you’re there. You can tour the 130-year-old USS Olympia, as well as the USS Becuna, one of the last surviving WWII Balao-class submarines.

While the community might never truly recover from the loss of the flagship Maker Faires in New York and California, we do take some comfort in knowing that smaller regional shows like this one have been growing over the last few several years. They’re not only a great way to connect with like-minded folks in your area, but can help you connect with maker-friendly vendors and organizations which you might otherwise be unaware of.