Every now and then, along comes an awesome hack from years past that we missed at the time. We kick ourselves for somehow missing such amazing work, and since it’s that good, we share it with you with apologies. Such is the case with [Andrei Anatska]’s faithful replication of the Pioneer CDJ-2000 user interface as an upgrade to the earlier CDJ-1000 DJ controller, a piece of work of such quality that you could almost mistake it for being a commercial product.
At its heart is the STM32F746G Discovery board, which for some reason it pleases us greatly in this context that he refers to as the Disco board. If you’re hazy on the details of the various STM dev boards, this is the all-singing all-dancing one with the fancy colour LCD display. Out comes the VFD on the CDJ-1000 and a set of wires are soldered to its main board, then the Disco board is hooked up with the project firmware installed. The piece de résistance is the case, for which he eschews 3D-printing and instead cuts out from black plastic. Full instructions can be found in this PDF, so should you happen to have a CDJ-1000 that’s seen better days, you can join in the fun. See it in action in the video below.
DJ controllers may be run-of-the-mill today, but to those of us whose DJing days were in the era of a pair of Technics SL1200s and a stack of vinyl to the sound of early ’90s house music they are still nothing short of miraculous. We’ve featured plenty of hacks involving them here but they don’t always involve professional kit. Even a game controller can be pressed into service.
Continue reading “Why Buy The Newer Model, When You Can Just Replicate Its User Interface?”
[Fabien-Chouteau] submitted his interesting solenoid engine. In an internal combustion, steam, or pneumatic piston engine, the motive force is produced by expanding gas. In [Fabien]’s little engine it is produced by the arm of a hard drive. Solenoid engines are usually just for show, and come in all shapes and sizes. If you want to move something using electricity an axial motor is probably a better bet. But if you want a challenge and a learning experience, this is hard to beat.
[Fabien] had some problems to solve before his motor made its first revolution. Just like a piston engine the timing needed to be exact. The arm firing at the wrong time could cause all sorts of trouble, the equivalent of backfire in a combustion engine. A STM32f4 discovery board was coupled with a Hall-effect sensor and a MOSFET. When the board read that the arm has moved back to the most efficient position for firing it sent a pulse through the coil. Just like a regular engine, getting the timing right makes all the difference. Once [Fabien] got it tuned up his motor could spin around at a steady 3000 rpm.
Continue reading “Software Controlled Hard Drive Solenoid Engine”
Tired of flashing your embedded project over and over just to tweak a few values? So was [Karl], so he wrote a text editor that runs on his ARM dev board.
Having trouble wrapping your mind around the need for this kind of thing? He’s actually playing around with eLua, the embedded version of the Lua programming language. In this case the program files are being stored on an SD card. But still, moving that back and forth between computer and embedded project gets old quickly. So he invested the time to write a rudimentary text editor that he interfaces through this terminal window. Above you can see the help screen which lays out all of the applications features. Right now it sounds like the only gotcha for this is the amount of RAM it needs to run. As it stands, the editor will now work an mbed board, but it works just fine on an STM Discovery.
When programming a microcontroller to do your bidding, you only have two choices. You could write your code in a proper language such as C and cross-compile your source into a piece of firmware easily understood by a micro. Alternatively, your could load an interpreter on your microcontroller and write code via a serial connection. Interpreters are a really fast and easy method to dig in to the hardware but unfortunately most microcontroller interpreters available are based on BASIC or Forth.
Espruino is designed for the STM32VL Discovery board, although [Gordon] plans on porting his interpreter to the Arduino Due when he can get his hands on one. Installation is as easy as uploading any other piece of firmware, and even though [Gordon]’s STM32VL doesn’t have a USB port for a serial terminal, it’s a snap to connect a USB to TTL converter and get this interpreter working.
Espruino isn’t open source yet, only because [Gordon] would like to clean up his code and write a bit of documentation. He’d also like to make Espruino profitable so he can work on it full-time, so if anyone has an idea on how [Gordon] can do that, leave a note in the comments.