Run a Korg SQ-1 Sequencer from a 9V Stompbox supply

 

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Run a Korg SQ-1 Sequencer from a 9V Stompbox supply:

The Korg SQ-1 is a great little sequencer, and one of my favourite bits of kit for its simple hands-on feel and penchant for lucky randomness (I have 3 of them!)
I tend to use it in a live setup with no computer but with a lot of guitar effect pedals on 9V daisy chain cables. The fact that the SQ-1 can only use batteries or USB power becomes a bit annoying so I decided to hack one so it can run on the same power supply as the pedals.

More details on Stuff and Nonsense blog.

Semiconductor radioactivity detector – part 2

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Robert Gawron has been working on a radioactivity detector, that is available on GitHub:

There are many ways to measure radioactivity level, semiconductor detectors sense interactions between ionizing radiation and p-n junction. Because in hobbyist area most popular are Geiger-Muller based detectors (in short: not a semiconductor but lamp based devices), I think it’s a cool idea to take a look at this approach.
In this post I will present such home-made sensor and a set of software to parse collected results.

See the full post on his blog. Be sure to see Part 1 here.

Making an e-Paper Etch-a-Sketch

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Scott Baker has been working on making an Etch-a-Sketch using modern e-Paper displays and optical encoders:

Above you can see my prototype. I’m using a 4.2″ e-Paper display from Gooddisplay, together with the Waveshare breakout board. I have a couple of ENS1J-B28-R00128 optical encoders that I attained on eBay. I specifically chose these encoders instead of traditional electro-mechnical encoders due to the high numbers of pulses per revolution. A typical electro-mechanical encoder will net about 24 pulses per revolution. The optical encoders I bought on ebay are 128 pulses per revolution. Our 4.2″ ePaper has 400×300 pixels. To traverse the major axis would require 16 full turns of the electromechical encoder but only 3 turns of the optical encoder.
The hardware is so simple that there’s not much more to say. The encoders are connected to GPIO pins of a Raspberry Pi. Note that there are resistors inline on the encoder outputs as the encoders are 5V and the Raspberry Pi uses 3.3V GPIO. The e-ink display is connected to the SPI bus.

See the full post on his blog here and the GitHub repository here.

Check out the video after the break.

Vintage headset conversion

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Quinn Dunki wrote a great article describing the conversion process of a 1980s-era Earmark into a bluetooth headset:

The obvious thing is to convert it to a bluetooth headset for modern use, right? As I previously warned, converting a 1980s-era air traffic control headset into bluetooth headphones is probably the most hipster thing possible. Normally, I don’t allow projects like this around here. But look at these headphones. They are amazing and I love them and I want to use them so I am going to make them bluetooth also shut up. If I have to punch myself as result of now being a hipster tool, so be it. I set out to do this in a non-destructive way that was reversible, at the very least. I wanted to respect the original hardware as much as possible.

Via Blondihacks.

Atari 5200 Playstation 2 dual-shock controller adapter

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Dr. Scott Baker has developed an adapter that allows you to use Playstation 2 analog controllers on an Atari 5200, that is available on gitHub:

This adapter allows you to use a PS2 controller on an Atari 5200 gaming console. The 5200 was notable at the time for its use of analog joysticks, but the controllers that shipped with the console are pretty lousy. They don’t self-center and they have a mushy annoying feel to them. The fire buttons aren’t very tactile in nature. The controller in my opinion just doesn’t feel or work good. Nevertheless, you have to give the Atari 5200 some respect for trying to be a pioneer in the technology.
As such, several solutions have been proposed for using alternate controllers. There are adapters for Atari 2600 digital sticks, adapters for analog PC joysticks, my own handheld controller, etc. I decided to adapt the basic technique of my handheld controller to a PS2 adapter.

See the full post on Dr. Scott M. Baker’s blog.

A software only solution to the vexing beagle bone black PHY issue

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Josh Levine has a nice write-up about a software only workaround for the Beagle Bone Black PHY issue:

Sometimes the Ethernet port on a Beagle Bone Black does not work on power up. It takes either a physical reset button press or a power cycle to fix it. This problem affects all BBB’s and until now could only be solved with hardware hacks.

The final official word from TI on this problem:
“There is no solution for this on the BB Black“

Full details at josh.com.

Emulating a hardware ROM in real time with an STM32F4

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ROM emulation using an STM32F4:

I remember reading dhole’s  Emulating a GameBoy Cartridge with an STM32F4 some time ago thinking that it had a lot of applications with respect to old computers. In that article  a STM32F4 microcontroller  ‘pretends to be a ROM chip for a gameboy’. At the start of a bus cycle, an interrupt is triggered in the STM32F4, it then reads the address bus of the gameboy’s 6502, checks the gameboy’s read/write line(s) and pulls data from its internal Flash and presents it onto the data bus long enough for the gameboy to read it, then tristates the databus. There are no wait states. It does this all within the 1000ns of the 1MHz Gameboy CPU clock. For all intensive purposes the gameboy thinks it has a real rom chip attached.

Full details at Kernelcrash.com .

Raspberry Pi virtual floppy for ISA (PC XT/AT) computers

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Dr. Scott M. Baker wrote an article detailing how he turned a Raspberry Pi into a virtual storage device for ISA bus computers:

I’m tired of carrying compact flash cards and/or floppies back and forth to my XT computer. I like to do development at my desk using my modern windows PC. While I can certainly use a KVM switch to interact with the retro computer from my Windows desktop, it would be a lot more convenient if I could also have a shared filesystem. There are several alternatives, from serial port solutions, to network adapters. However, I wanted something that would emulate a simple disk device, like a floppy drive, something I could even boot off of, so I implemented a virtual floppy served from a Raspberry pi.

See the full post on his blog here.

Check out the video after the break.