Pebble Darkroom is a specialized timer application designed for film and print development in darkroom photography. The app provides separate timers for each stage of the development process, with dedicated support for both RC (Resin Coated) and Fiber paper types. Each timer features distinct visual themes and stage progressions optimized for professional darkroom workflows.
- Dual Timer System: Run two independent timers simultaneously for managing multiple development processes
- Paper-Specific Modes:
- Timer 1: RC (Resin Coated) paper with 4-stage processing and light theme
- Timer 2: Fiber paper with 6-stage processing including hypo clear and extended wash cycles, with dark theme
- Film Mode: Traditional film development process available on both timers
- Extended Stage Support:
- RC Paper: Develop → Stop → Fix → Wash (4 stages)
- Fiber Paper: Develop → Stop → Fix → Wash1 → Hypo Clear → Wash2 (6 stages)
- Enhanced Visual Design: Larger fonts and improved readability for darkroom conditions
- Smart Mode Indicators: Clear display format showing paper type, mode, and current stage
- Customizable Timing: Independent timing configuration for RC and Fiber paper workflows
- Display Themes: Automatic light/dark themes with optional color inversion
- Haptic Feedback: Distinctive vibration patterns for each timer
- Pause/Resume: Full control over timer progression
- Manual Stage Advancement: Timers don't automatically start the next stage, giving you full control
- Screen Refresh: Force screen refresh to address screen tearing
Note: Screenshots below show the previous interface. The enhanced version features larger fonts, improved mode indicators showing paper types (RC/FB), and updated visual themes with Timer 1 defaulting to light mode and Timer 2 to dark mode.
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UP Button:
- Double-Click: Switch between Timer 1 and Timer 2
- Long Press: Force screen refresh (helps with screen tearing)
-
SELECT Button (Middle):
- Press: Open settings menu
-
DOWN Button:
- Press: Start/Pause/Resume the active timer
- Long Press: Reset the active timer
- Double-Click: Toggle between Film and Print modes
-
Starting a Development Process:
- Select desired timer (Timer 1 or Timer 2) using UP double-click
- Choose Film or Print mode using DOWN double-click
- Press DOWN button to start the first stage (Develop)
-
Paper Type Selection:
- Timer 1 (Print Mode): Automatically configured for RC paper processing
- Timer 2 (Print Mode): Automatically configured for Fiber paper processing
- Film Mode: Available on both timers with traditional 4-stage process
-
Between Stages:
- When a stage completes, the app will:
- Vibrate with a pattern specific to the active timer
- Timer 1: Single pulse
- Timer 2: Double pulse
- The app will automatically advance to the next stage but will wait for you to start it
- After 2 seconds, a reminder vibration occurs with the same pattern
- Press DOWN button to start the next stage when ready
- When a stage completes, the app will:
-
Pausing/Resuming:
- Press DOWN button once to pause a running timer
- Press DOWN button again to resume the timer
The app uses an enhanced display format: [Mode] | [Paper Type] | [Stage] | [Status]
- Mode Indicators:
P= Print modeF= Film mode
- Paper Type Indicators (Print mode only):
RC= RC (Resin Coated) paper (Timer 1)FB= Fiber paper (Timer 2)
- Stage Indicators:
- RC Paper:
Dev,Stop,Fix,Wash - Fiber Paper:
Dev,Stop,Fix,Wash1,HC(Hypo Clear),Wash2 - Film:
Dev,Stop,Fix,Wash
- RC Paper:
- Status:
RUNNING,PAUSED, or blank when stopped - Visual Themes:
- Timer 1: Light background with black text (default)
- Timer 2: Dark background with white text (default)
- Progress bar shows current stage position relative to total stages
- Timer display shows remaining time in minutes:seconds format with larger, more readable fonts
Access the settings menu by pressing the SELECT button.
- Vibration: Toggle vibration alerts on/off
- Backlight: Toggle screen backlight on/off
- Invert Timer 1: Toggle color inversion for Timer 1
- Invert Timer 2: Toggle color inversion for Timer 2
- Invert Menu: Toggle color inversion for settings menu
Customize seconds for each film development stage:
- Develop (default: 5:00)
- Stop (default: 1:00)
- Fix (default: 5:00)
- Wash (default: 5:00)
Customize seconds for each RC paper development stage:
- Develop (default: 1:00)
- Stop (default: 0:30)
- Fix (default: 5:00)
- Wash (default: 5:00)
Customize seconds for each Fiber paper development stage:
- Develop (default: 2:00)
- Stop (default: 0:30)
- Fix (default: 2:00)
- Wash1 (default: 5:00)
- Hypo Clear (default: 2:00)
- Wash2 (default: 15:00)
- Double-click UP to select Timer 1 (light theme)
- Double-click DOWN to set Print mode
- The display will show
P | RC | Dev |indicating RC paper mode - Follow the 4-stage process: Develop → Stop → Fix → Wash
- Timer 1 uses optimized timing for RC paper's faster processing
- Double-click UP to select Timer 2 (dark theme)
- Double-click DOWN to set Print mode
- The display will show
P | FB | Dev |indicating Fiber paper mode - Follow the 6-stage process: Develop → Stop → Fix → Wash1 → HC → Wash2
- Timer 2 includes hypo clear stage and extended wash cycles for proper fiber processing
- Set Timer 1 to Print mode for RC paper
- Set Timer 2 to Print mode for Fiber paper
- Start Timer 1 for RC paper development
- Double-click UP to switch to Timer 2
- Start Timer 2 for Fiber paper development
- Switch between timers as needed - each maintains its own stage progression
- Visual themes help distinguish between the two processes at a glance
RC (Resin Coated) Paper - Timer 1:
- Faster processing with 4 stages
- Shorter wash times due to resin coating
- Light theme for easy identification
- Typical workflow: 1 min develop, 30 sec stop, 5 min fix, 5 min wash
Fiber Paper - Timer 2:
- Extended processing with 6 stages
- Requires hypo clear treatment to remove residual fixer
- Longer wash cycles for archival processing
- Dark theme for easy identification
- Typical workflow: 2 min develop, 30 sec stop, 2 min fix, 5 min wash1, 2 min hypo clear, 15 min wash2
- Select either Timer 1 or Timer 2 using UP double-click
- Set to Film mode using DOWN double-click
- Both timers support traditional 4-stage film development
- Use both timers for different film types or simultaneous processing
- Enable Backlight setting if needed
- Timer 1 (light theme) and Timer 2 (dark theme) provide visual distinction
- Consider inverting display colors for better visibility
- Use haptic feedback to track timer completion
- Larger fonts improve readability in low-light conditions
- Docker
- Make
- Pebble smartphone app installed on your device
- Rebble web services setup (optional)
- Clone the repository:
git clone https://github.com/toozej/pebble-darkroom.git
cd pebble-darkroom- Build the app using Docker:
make build copy- Enable Developer Mode in the Pebble smartphone app, noting your phone's IP address
- Ensure your phone and Pebble watch are connected
- Run the following command:
cd pebble-darkroom/
pebble clean
pebble install --phone <YOUR_PHONE_IP>- Build the app as described above
- Locate the
.pbwfile in thebuilddirectory - Send this file to your phone
- Open the file with the Pebble app to install
The app saves your settings between sessions, including:
- Vibration and backlight preferences
- Color inversion settings
- Custom timer durations for each stage
If you experience screen tearing (horizontal lines across the display):
- Long-press the UP button to force a screen refresh
- If the issue persists, try this fix
If the timer completes but doesn't seem to advance to the next stage:
- Check that vibration is enabled in settings
- Remember that you need to manually start each stage with the DOWN button
- Verify that the watch hasn't entered power-saving mode
- Note that RC paper has 4 stages while Fiber paper has 6 stages - ensure you're expecting the correct number of stages for your paper type
If your custom settings aren't persisting between app launches:
- Make sure to fully exit the settings menu before closing the app
- Check that your Pebble has sufficient storage space available
- Try rebuilding and reinstalling the app
- Note that RC and Fiber paper settings are stored separately - changes to one won't affect the other
If you're unsure which paper type is active:
- Check the mode indicator:
RCfor Timer 1,FBfor Timer 2 in print mode - Timer 1 defaults to light theme, Timer 2 to dark theme
- RC paper shows 4 stages, Fiber paper shows 6 stages in the progress indicator
- Fiber paper includes
HC(Hypo Clear) andWash2stages that RC paper doesn't have


