kpucynski · kpucynski · Feb 12, 2026 · Feb 12, 2026 · Feb 12, 2026 · Feb 12, 2026
diff --git a/DOOM_README.md b/DOOM_README.md
@@ -0,0 +1,138 @@
+# DOOM on EdgeTX — RadioMaster TX15
+
+Port of the DOOM game engine to the latest EdgeTX codebase, targeting the RadioMaster TX15 (STM32H750, 480x272 LCD).
+
+Based on the earlier [edgetx-doom](https://github.com/DavBfr/edgetx-doom) proof-of-concept, updated to work with the current EdgeTX architecture and APIs.
+
+> **Note:** This port was heavily AI-assisted (GitHub Copilot / Claude). All code changes — API migration, build integration, runtime fixes — were produced in an interactive AI-assisted session.
+
+## What it does
+
+- Runs DOOM (shareware or full) on the TX15 hardware
+- Reads `DOOM1.WAD` from the SD card at `/DOOM/DOOM1.WAD`
+- Renders at 320×200 internal resolution, scaled to 480×272 via nearest-neighbor
+- **Sound effects** — all 109 SFX from the WAD, resampled and mixed in real-time
+- **Music** — MUS format playback via triangle/square-wave synthesis (chiptune style)
+- **Gimbal controls** — dual-stick layout (left: move/strafe, right: turn) for intuitive FPS gameplay
+- Hardware buttons mapped for menu navigation and alternate controls
+- Long-press power button to shut down
+
+## Prerequisites
+
+- ARM GNU Toolchain (tested with 14.2.rel1)
+- Python 3 with packages: `jinja2`, `pillow`, `lz4`, `clang`, `pyelftools`
+- A `DOOM1.WAD` file (shareware or registered)
+
+## How to build
+
+### Configure
+
+```bash
+cmake --preset firmware \
+  -DPCB=TX15 \
+  -DDEFAULT_MODE=2 \
+  -DGVARS=YES \
+  -DWITH_DOOM=ON
+```
+
+### Compile
+
+```bash
+cd build/fw
+make -j$(nproc) firmware
+```
+
+The output `firmware.uf2` is ready to flash.
+
+## How to flash
+
+1. Copy `DOOM1.WAD` to `/DOOM/` on the TX15 SD card
+2. Power off the TX15
+3. Hold trim buttons and connect USB to enter DFU/UF2 mode
+4. Copy `firmware.uf2` to the USB mass storage drive
+5. Radio reboots into DOOM
+
+## Controls
+
+### Gimbals (Analog Sticks)
+
+| Gimbal | DOOM Action |
+| -------- | ------------- |
+| Left stick vertical | Move forward / backward |
+| Left stick horizontal | Turn left / right |
+| Right stick horizontal | Strafe left / right |
+
+### Buttons
+
+| TX15 Button | DOOM Action |
+| ----------- | ----------- |
+| RTN | Move forward |
+| TELE | Move backward |
+| PAGE< | Turn left |
+| PAGE> | Turn right |
+| MDL | Fire |
+| ROLL (push) | Use (open doors, switches) |
+| SYS | Open menu (Esc) |
+| Power (long press) | Shut down |
+
+**Note:**
+
+- Gimbal controls are disabled in menus to avoid navigation conflicts
+- ROLL button acts as ENTER in menus for selection/confirmation, and as USE in-game for doors/switches
+
+## Changes to EdgeTX core
+
+All changes are gated behind `#if defined(WITH_DOOM)` — zero impact on normal builds.
+
+| File | Change |
+| ------ | -------- |
+| `radio/src/CMakeLists.txt` | `WITH_DOOM` option, include doom subdirectory |
+| `radio/src/tasks.cpp` | DOOM RTOS task (32KB stack) as alternative to menus/audio tasks |
+| `radio/src/edgetx.cpp` | Skip LVGL init when `WITH_DOOM` is defined |
+| `radio/src/model_init.cpp` | Skip COLORLCD layout factory when `WITH_DOOM` is defined |
+| `radio/src/sdcard.h` | `DOOM_PATH` definition |
+| `radio/src/audio.h` | `AUDIO_BUFFER_COUNT = 6` for DOOM builds (covers one game frame) |
+| `radio/src/gui/colorlcd/mainview/view_statistics.cpp` | Guard stack display with `#ifndef WITH_DOOM` |
+
+## New files
+
+- `radio/src/doom/` — Full DOOM engine (chocolate-doom based), ~180 source files
+- `radio/src/doom/edgetx/` — EdgeTX integration layer:
+  - `display.cpp` / `display.h` — LCD framebuffer interface
+  - `doomgeneric.cpp` / `doomgeneric.h` — Hardware init, input, timing
+  - `doom_main.h` — Entry point declaration
+  - `sound.cpp` / `sound.h` — SFX audio module (`sound_module_t`)
+  - `music.cpp` / `music.h` — MUS music module (`music_module_t`)
+
+## Technical details
+
+- **Display**: DOOM writes directly to the LTDC framebuffer in RGB565, bypassing the LVGL GUI stack entirely
+- **D-Cache**: `SCB_CleanDCache()` after framebuffer writes so the LTDC peripheral sees CPU writes to SDRAM
+- **Watchdog**: `WDG_RESET()` in game loop, sleep/tick functions, and WAD I/O to survive the 500ms hardware watchdog
+- **Memory**: DOOM zone allocator uses 2MB from SDRAM heap via `malloc`
+- **WAD I/O**: Uses FatFS (`f_open` / `f_read` / `f_lseek`) to read WAD files from the SD card
+- **Scaling**: 320×200 → 480×272 nearest-neighbor, palette-indexed to RGB565 conversion per frame
+
+### Input
+
+- **Analog gimbals**: Read via `getADC()` / `evalInputs()` from `calibratedAnalogs[]` array (range: -1024 to +1024)
+- **Deadzone**: 6.5% of full range applied to eliminate stick drift
+- **Movement threshold**: 20% of full range triggers digital key events (forward/back/strafe)
+- **Turning**: Left stick horizontal mapped to DOOM joystick axis (`AD_RH`) for smooth analog turning (inverted: stick left → turn right)
+- **Digital buttons**: 16-entry keymap indexed by `EnumKeys` (0-15), supports press/release events
+- **Menu behavior**: Analog stick inputs disabled in menus to prevent navigation conflicts; buttons continue to work
+
+### Audio
+
+- **Hardware path**: EdgeTX AudioBufferFifo → DMA → SPI2 (I2S) → TAS2505 codec → speaker
+- **Format**: 32 kHz, 16-bit signed, mono
+- **SFX pipeline**: WAD lump loading → 8-bit unsigned to 16-bit signed conversion → linear-interpolation resampling (11025 → 32000 Hz) → up to 8-channel mixing → AudioBufferFifo
+- **SFX cache**: Up to 64 decoded/resampled sounds kept in memory to avoid re-processing
+- **Music pipeline**: MUS format parser → 140 tick/sec sequencer → per-sample waveform synthesis (triangle/square blend for melodic, filtered LFSR noise for percussion) → mixed into the same audio buffer as SFX
+- **Music voices**: 16 channels (0-14 melodic, 15 percussion), with per-channel volume, pitch bend, attack/release envelopes, and 1-pole low-pass filtering
+- **Music waveforms**: Melodic channels use a 75% triangle / 25% square blend for warm tone with audible bass; percussion uses filtered LFSR noise (±8000 amplitude with 1/2 old + 1/2 new low-pass) for smooth, non-crackly hi-hats and moderate decay
+- **Buffer strategy**: 6 × 10 ms buffers (320 samples each) to cover one game frame (~28 ms at 35 fps)
+
+## License
+
+DOOM engine source is licensed under GPLv2. See `radio/src/doom/` file headers for details.
diff --git a/radio/src/CMakeLists.txt b/radio/src/CMakeLists.txt
@@ -60,6 +60,7 @@ else()
   option(USBJ_EX "Enable USB Joystick Extension" ON)
 endif()
 option(AUDIO "Enable audio" ON)
+option(WITH_DOOM "Enable doom" OFF)
 
 if(NATIVE_BUILD)
   option(ALL_LANGUAGES "Enable runtime language selection" ON)
@@ -204,6 +205,10 @@ if(LUA)
   include(lua/CMakeLists.txt)
 endif()
 
+if(WITH_DOOM)
+  include(doom/CMakeLists.txt)
+endif()
+
 if(HELI)
   add_definitions(-DHELI)
 endif()

diff --git a/radio/src/audio.h b/radio/src/audio.h
@@ -90,6 +90,8 @@ constexpr uint8_t AUDIO_FILENAME_MAXLEN = (AUDIO_LUA_FILENAME_MAXLEN > AUDIO_MOD
 
 #if defined(SIMU)
   #define AUDIO_BUFFER_COUNT           (10) // simulator needs more buffers for smooth audio
+#elif defined(WITH_DOOM)
+  #define AUDIO_BUFFER_COUNT           (6)  // DOOM needs enough buffers to cover one game frame (~28ms)
 #elif defined(AUDIO_SPI)
   #define AUDIO_BUFFER_COUNT           (2)  // smaller than Taranis since there is also a buffer on the ADC chip
 #elif defined(STORAGE_USE_SPI_FLASH)

diff --git a/radio/src/doom/CMakeLists.txt b/radio/src/doom/CMakeLists.txt
@@ -0,0 +1,18 @@
+
+set(SRC ${SRC}
+  doom/doomdef.c doom/hu_lib.c doom/i_timer.c doom/m_fixed.c doom/p_lights.c doom/p_switch.c doom/r_sky.c doom/w_checksum.c
+  doom/am_map.c doom/hu_stuff.c doom/i_video.c doom/m_menu.c doom/p_map.c doom/p_telept.c doom/r_things.c doom/w_file.c
+  doom/i_cdmus.c doom/icon.c doom/m_misc.c doom/p_maputl.c doom/p_tick.c doom/s_sound.c doom/w_main.c
+  doom/d_event.c doom/doomstat.c doom/i_endoom.c doom/m_random.c doom/p_mobj.c doom/p_user.c doom/sha1.c doom/w_wad.c
+  doom/d_items.c doom/dstrings.c doom/i_input.c doom/info.c doom/memio.c doom/p_plats.c doom/r_bsp.c doom/sounds.c doom/wi_stuff.c
+  doom/d_iwad.c doom/dummy.c doom/i_joystick.c doom/m_argv.c doom/p_ceilng.c doom/p_pspr.c doom/r_data.c doom/st_lib.c doom/z_zone.c
+  doom/d_loop.c doom/f_finale.c doom/i_main.c doom/m_bbox.c doom/p_doors.c doom/p_saveg.c doom/r_draw.c doom/st_stuff.c
+  doom/d_main.c doom/f_wipe.c doom/i_scale.c doom/m_cheat.c doom/p_enemy.c doom/p_setup.c doom/r_main.c doom/statdump.c
+  doom/d_mode.c doom/g_game.c doom/i_sound.c doom/m_config.c doom/p_floor.c doom/p_sight.c doom/r_plane.c doom/tables.c
+  doom/d_net.c doom/gusconf.c doom/i_system.c doom/m_controls.c doom/p_inter.c doom/p_spec.c doom/r_segs.c doom/v_video.c doom/edgetx/display.cpp doom/edgetx/doomgeneric.cpp doom/edgetx/sound.cpp doom/edgetx/music.cpp
+)
+
+message(STATUS "Build DOOM firmware")
+
+include_directories(doom/include doom/edgetx)
+add_compile_definitions(WITH_DOOM)