R36S M8 Tracker Handheld

Overview

This project turns an R36S handheld console into a compact, pocketable music tracker running the Dirtywave M8 Tracker software. It uses the R36S handheld running the DarkOS Linux distribution, paired with a Teensy 4.1 running the M8 Tracker firmware.

The goal of the project was to create a cleaner and more portable version of a common DIY M8 Tracker setup. Many existing builds leave the Teensy attached externally as a dongle, often hanging from the side of the R36S, with extra cables routed around the device. This build instead integrates the Teensy internally and replaces the original rear shell with a custom slim back case.

Hardware Used

• R36S handheld console
• DarkOS Linux distribution
• Teensy 4.1
• Dirtywave M8 Tracker software
• Custom 3D-printed rear shell
• USB micro-USB-C cable
• Original R36S front buttons and controls

Design Goals

The main design goals were:

• Make the R36S M8 Tracker setup pocketable
• Remove external dongles and loose USB-C cables
• Route wiring internally
• Provide a secure internal mount for the Teensy 4.1
• Improve ergonomics for handheld music tracking
• Reduce the overall thickness of the device

Custom Rear Shell

A new rear case was designed in Fusion 360. The original R36S shoulder triggers, including R1, R2, L1, and L2, were removed in favor of a much slimmer housing.

The custom back includes:

• A new battery compartment
• Internal wire routing space
• A dedicated seat for the Teensy 4.1
• A port for the Teensy heatsink
• A slimmed-down profile for better pocketability

The Teensy 4.1 can get quite warm during use, so the case includes an opening for the heatsink to help with thermal management.

Internal Wiring

One of the biggest improvements over typical builds is the internal USB routing. Since the R36S USB-C OTG port is located at the bottom of the device, external Teensy builds often require awkward cable placement. By redesigning the rear shell and battery compartment, the wiring can be routed inside the handheld instead.

This keeps the final device self-contained and much cleaner to use.

Front Panel Experiment

A custom front panel and revised button arrangement were also designed. The new layout looked and felt promising, and the physical design turned out well.

However, wiring the new buttons to the existing R36S PCB proved difficult because the traces on the board were extremely small. Because of this, the final build uses the standard R36S buttons instead of the custom front button arrangement.

Although the custom front panel was not used in the final version, it remains a useful part of the design process and could be revisited in a future revision.

Current Status

The project successfully creates a compact R36S-based M8 Tracker with the Teensy mounted internally. The custom rear shell makes the device slimmer, cleaner, and more portable than typical external Teensy builds.

The standard front controls are retained for reliability, while the redesigned rear housing provides the main improvement: a practical, handheld tracker with no dongle or loose external cabling.

Notes for Future Revisions

Potential improvements for a future version include:

• Revisiting the custom front panel
• Get proper buttons, not 3d printed buttons as they printed rough, and can snap off inside the switches
• Improving thermal ventilation around the Teensy
• Refining the internal cable routing - the teensy micro usb cable side could benefit from a flat 90 degree angled cable
• Counter sinking screws

Credits

This project is based on the wider community practice of running Dirtywave M8 Tracker software on a Teensy 4.1 with an R36S handheld as the host device. This version focuses on making the build cleaner, slimmer, and more pocketable through a custom rear shell and internalized wiring.