Rasteri’s SC1000 scratch controller — build your own today

Andy Tait, better know to many of you as Rasteri, has electronics skills to die for. And the he’s not repairing stuff for a living, or continuing to bring the brilliant 7PS to life, he’s doing his own thing. His own thing just happens to be the pocket sized SC1000 scratch controller. I’ve covered it before and coveted one for my very own, but it was clear that rather than being a commercial project, it would at best be open source. Andy has now opened that source as it were, and posted the whole thing on Github along with shopping lists and firmware.

Here’s a quick sample of what it can do: 

But before you get too excited at the prospect of ten minutes of IKEA style flat pack assembly, you’re going to need to be adept, nay very confident with a soldering iron. The basic process is outlined in the Github documentation, and is not for the faint-hearted. Even those confident with serious portablist mods may get a case of the collywobbles after reading that this is essentially like going to the factory storeroom and building it from… umm scratch. 

The basic process is this:

Order the Main and Enclosure PCBs, the components, the A13 SoM, and SD Card, and the Aluminium bar.

Assemble the Main PCB. I recommend assembling/testing the 3.3v power section first, so you don’t blow all the other components. Don’t connect the A13 module yet.

Flash the input processor with its firmware through connector J8. You will need a PIC programmer, such as the Microchip Pickit 3. The firmware hex file is firmware/firmware.hex

Transfer the operating system to the SD card. You will need an SD card interface, either USB or built-in to your PC. You can use dd on Linux/MacOS or Etcher on Windows to transfer the image. The image is os/sdcard.img.gz

Insert the SD card in the A13 module, and attach the SoM to the main PCB. Make sure it’s the correct way round – the SD card should be right beside the USB storage connector on the rear of the SC1000.

Connect a USB power source, and power up the unit to test – the A13 module’s green light should blink a few times before remaining on.

Assemble the jogwheel – glue the bearing into the hole in the top plate of the enclosure. Now glue the magnet to the tip of the M8 bolt. Attach the jogwheel to the bearing using the bolt/nut/washer. Solder a wire to the outside of the bearing to act as a capacitive touch sensor.

Connect the fader to J1, capacitive touch sensor to J4, and (optionally) a small internal USB power bank to J3. If you don’t use an internal power bank, put two jumpers horizontally across J3 to allow the power to bypass it.

Test – copy some beats and samples to a USB stick, and see if they play. Check below for how to structure the folders on the USB stick.

Assemble the enclosure – drill and tap M3 holes in the aluminium, and screw the whole enclosure together. Make sure the magnet at the end of the jogwheel bolt is suspended directly above the rotary sensor IC.

This however is the video version. Obviously at just 6 minutes long, it’s a rather speedy walkthrough, but it does give the general idea:

 

Reading that list, the hardest part for most people is likely to be the soldering of components to the board. And it’s at this point that it struck me that there’s a small commercial opportunity for someone to knock out a number of populated boards so that this does become considerably closer to a self assembly kit. Indeed, there’s probably a few quid in someone selling them as complete units too. Plug and play is a thing for a very good reason.

Rasteri's SC1000 scratch controller — build your own today


Given the home brew nature of the product, it’s more than open to user mods too. As I mentioned in my last piece, I suspect the jog wheel would have scope for user customisation, but the case too. I wouldn’t be at all surprised if more advanced mods came out such as tweaks to firmware. There are a number of clever people capable of such things, and I’m sure Andy would welcome it, hence making the project open source in the first place. 

I think my inner nerd is calling me, and he’s getting the soldering iron warm.