DF_DMC_2_MC

Dragonframe DMC v2 USB bridge for DIY motorized camera sliders — C++ / PlatformIO on a Waveshare RP2040-Zero, talking SliderMC ASCII over UART.

About

DF_DMC_2_MC lets Dragonframe Arc drive the same motion board as the physical panel (SliderCtrl). The PC speaks binary DMC v2 on USB CDC; this Zero translates millimetre moves, path play, GIO, camera, and live DMX onto SliderMC’s UART contract (VH, CG, MT, PG, …).

Use it instead of a UIC on that UART, not in parallel. Rail, motor, and housing stay yours.

Documentation: docs/README.md

Slider context (rail, panel, MC UART): SliderDoc.

Dragonframe (PC)
        USB CDC  — binary DMC v2  (device type dmc-lite)
DF_DMC_2_MC  (RP2040-Zero)
        UART 115200  GP12 TX / GP13 RX
SliderMC

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Features

• Connect as dmc-lite — hello name jDF-MC V1 <motors>M+<servos>S+6L+4O+4I+CT+DMX; Arc steps per unit = 1000
• Units — 1000 DMC steps = 1 mm or 1 deg (same for speed/accel)
• Live GIO — 4 out (GP1–4) / 4 in (GP5–8) on this Zero, not MC extenders
• DMX512 — 512 channels on GP0 (PIO UART + MAX485 for a real universe). Channels 1–6 also drive DMX1–DMX6 PWM at 18 kHz on GP29, GP28, GP27, GP26, GP15, GP14 (high-active, duty = level/255)
• MOVE — GP11 high while the verbose status letter is M, A, B, H, or P
• Camera / bloop — GP9 shutter + MC CT; GP10 buzzer + MC BE
• Path upload — DF frames → SliderMC PD / PG (0-based inclusive; reverse if start > end)
• Simulator — -DSIMULATE (default): 1-axis stand-in if no MC answers

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Flash a release

No compiler and no PlatformIO. Board: Waveshare RP2040-Zero.

1. Download DF_DMC_2_MC-<tag>-rp2040zero.uf2 from the Releases page.
2. Hold BOOTSEL, plug in USB, then release BOOTSEL.
3. Copy the UF2 onto the RPI-RP2 drive. The board reboots into the new firmware.

The file is the default firmware, including -DSIMULATE (a 1-axis stand-in only if no SliderMC answers). USB CDC is binary DMC, not a text console.

A new file is built when a v* tag is pushed. That tag's commit must already contain this workflow. Rebuild an existing tag from the Actions page with Run workflow.

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Quick start (VS Code)

1. Install VS Code and the PlatformIO IDE extension.
2. File → Open Folder → this repository (DF_DMC_2_MC).
3. PlatformIO: Build / Upload.
4. Dragonframe: Scene → Connections → device type dmc-lite → this COM port → Connect.
5. In Arc, set steps per unit = 1000.

Shared DMC framing, the path upload table, DMX, and GIO come from the sibling checkout DF_DMC_Common (../DF_DMC_Common). Clone it next to this repo before building.

USB CDC is binary DMC — do not use the PlatformIO serial monitor as a console. Details: docs/build.md.

PC smoke test (Dragonframe disconnected): python pc_dmc_test.py COM21 --sequence hi — see docs/build.md.

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Documentation

Topic	Document
Overview / Connect / units	docs/overview.md
Build / flash / PC test	docs/build.md
GPIO / UART / wiring	docs/pins.md
DMC opcode → MC map	docs/mapping.md
SliderMC UART	contract/protocol.md
Official DMC v2 (Dragonframe)	DMC-Protocol-2024-08-13.pdf

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Repository layout

src/config.h         Pins, limits, 1000 steps = 1 mm/deg
src/path_store       DF upload → PD samples (positions in DF_DMC_Common)
src/mc_client        SliderMC UART + simulator
src/status_led       WS2812 / classic LED
src/bridge           USB DMC dispatch
src/main.cpp         setup() / loop()
pc_dmc_test.py       Host DMC smoke test

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License

Copyright (c) 2026 Jochen Krapf <jk@nerd2nerd.org>

Licensed under the MIT License.

Company names and product names mentioned in this project are trademarks or registered trademarks of their respective owners. Use here is for identification only.