MulletRhythm 9090 (MR-9090)

24.11.2010: Added errata for schematic and a note about wiping the memory before use.

11.4.2008: Prototype assembled.

10.2.2008: v1.1 firmware released. See change log here. Only firmware - no hardware changes.

10.2.2008: HEX to SYX converter released for converting the compiled firmware to a MIDI uploadable .syx file.

Welcome to the MR-9090 Step Sequencer project page! On this page you will find information about a home-brew 18F4x2 PIC micro controller based step sequencer mimicking the functionality of Roland's popular TR-series step sequencers such as TR-909 and TR-707.

Contents

   Project background
   Donations
   Licence
   Sequencer features
   Prototype
   Schematics & Hardware design
   Firmware & Sources
   Tools

Project background

The project began after I've successfully finished Trevor's fantastic TR-909 sound module clone TR-9090 (www.introspectiv.org). The original TR-9090 was supposed to be used with an external MIDI-sequencer which didn't suit me personally very well as I'm a bit of a fan of old hardware sequencers. Before working on the TR-9090 project I had built a TB-303 clone (www.acidcode.de) which was based on 18F452 PIC micro controller. The hardware design on the TB-303 clone was quite simple and I started thinking of doing my own step sequencer for the TR-9090 ... and this is how the MR-9090 sequencer project was born.

The hardware design of the prototype and especially the firmware implementation has taken quite lot of my time. The project began in February 2005 and has taken over a year in calendar time. I decided to release this work to the public and I hope this project ends up being useful for some other DIY fools out there. Read on for licence details.

Donations

Feel free to support the project by donating!

Licence

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 2.5 Finland License.

The hardware (schematics design) and the software (firmware) is released under Creative Commons by-nc-sa licence. The licence basicly dictates that all derivative works must be released under the same licence, all works must be non-commercial and shared. I decided to release this work to the public and I hope all the feature enhancements and bug fixes you implement out there will get released to the public too!

Sequencer features

• 16 steps
• 64 patterns organized in 4 banks (A, B, C and D) of 16 patterns
• Fill function - a programmable "Fill pattern" / pattern
• 16 Tracks of 354 measures each (1 - 4 x repeat support per measure)
• TR-909 based instrument tracks (bd, sd, lt, mt, ht, rs, hc, chh, ohh, cc, rc + total accent)
• TR-9090 compatible trigger circuit
• Shuffle
• Scales (1/16th notes, 1/32th notes, 1/8th triplets, 1/16th triplets)
• Individual accents and flams (4 variations) on each instrument
• Individual pattern length on each instrument
• Play and write modes changeable while the sequencer is running
• Programmable pattern chains in play mode (16 patterns)
• 16x2 LCD display
• Potentiometer controlled tempo (30 - 285 bpm)
• Roland compatible 24 ppqn din sync, input and output (3-pin compatible, does not support 'continue')
• MIDI input (sync) and output (sync & notes), firmware updateable via MIDI
• Converts MIDI sync to DIN sync and vice versa
• Low latency, uses 40MHz micro controller

Features planned for future releases:

• Optional 16x12 led matrix display for pattern triggers

Prototype

The front panel layout of the prototype is shown in the picture below (pdf):

(old version for firmware version 1.0 pdf)

Schematics & Hardware design

V1.0.x Schematics

v101schematicerrata.txt		V1.0.1 schematic errata.
v101_tobebuilt.pdf		V1.0.1 schematic of the circuitry needed for MR-9090. This is the actual circuitry needed to be built in addition to the TR-9090 boards.
v101_tobebuilt.sch		gEDA/gschem (version 20040111) file of the above.
v101_all.pdf		V1.0.1 schematic of the full sequencer circuitry including circuits present on the TR-9090 board. This basicly includes the TR-9090 trigger circuitry to the v10_tobebuilt.pdf.
v101_all.sch		gEDA/gschem (version 20040111) file of the above.
v10tov101errata.txt		Changes from v1.0 to v1.0.1.
v10_tobebuilt.pdf		V1.0 schematic of the circuitry needed for MR-9090. This is the actual circuitry needed to be built in addition to the TR-9090 boards.
v10_tobebuilt.sch		gEDA/gschem (version 20040111) file of the above.
v10_all.pdf		V1.0 schematic of the full sequencer circuitry including circuits present on the TR-9090 board. This basicly includes the TR-9090 trigger circuitry to the v10_tobebuilt.pdf.
v10_all.sch		gEDA/gschem (version 20040111) file of the above.

Firmware & Sources

Please wipe the flash memory before use. Hold the START button when starting up the sequencer and confirm the memory wipe with ENTER key.

src/		Online sources of v1.1 firmware
mulletrhythm9090v11.zip		Distribution package of v1.1 firmware and sources. CHANGES
mulletrhythm9090v10.zip		Distribution package of v1.0 firmware and sources. Includes MPLAB built .HEX-files for v1.0 firmware with and without bootloader.

Tools

syxconverter-1.0.zip

Java written tool to convert MPASM's HEX files to MIDI uploadable sysex files.