What is an SC1000?

The SC1000 is a portable open-source digital scratch instrument which loads samples and beats from a USB stick. [...]

The device, including its enclosure, uses no custom parts apart from printed circuit boards. It will be possible for anyone with a bit of electronics know-how to build one [...]
– github.com/rasteri/SC1000

All code and assembly instructions can be found in the repository. But if you're too lazy, like me, pre-assembled devices can be purchased at portablismgear.com

LED mod

The metal platter on the SC does not have a motor and therefore doesn't spin by itself. The rotation is just determined by a magnetic field sensor, which is super cool, because there's no wear out. But sometimes it's tricky to track the actual platter position, which is "virtual", because – as mentioned – it doesn't actually spin.

The idea is to add a LED ring to give visual feedback of the current rotation angle, as you would get from a sticker on a normal vinyl record, which is very common in DJing.

Pull request with code and documentation: github.com/rasteri/SC1000/pull/15

Concept

• The C code has been extended to send the current rotation angle in degrees on uart3-tx (J7 pin5) in form of a RPC
• an ESP8266 receives this RPC call via UART and updates the attached ws2812 LED ring/stripe accordingly
• the LED pattern is configurable (also see sc1000-led-configurator)

Another option would be to directly attach the LED ring to the Olimex inside the SC. But the ws2812 protocol requires strict timing (to address all LEDs individually), which is way easier on a micro controller than on a multi-user linux environment.

As side effect, the ESP also supports wifi out-of-the-box, which can be used to configure the LEDs (see SC1000 LED configurator).