Kinetic installation software for a Raspberry Pi that drives stepper motors in response to live tide and wave data from Newfoundland.
Adam collected the eponymous object featured in Driftwood from the Atlantic Ocean off the coast of Newfoundland, his family’s homeland. In this kinetic installation, a microelectronic system controls the driftwood’s movement. This system receives transmissions of live data from a buoy located in the Atlantic ocean off the coast of Newfoundland. The electronics translate the data into motion, enabling the driftwood to respond in real-time to the movement of the ocean. Though we don’t see the ocean, the installation evokes it: the driftwood moves rhythmically through the negative space, just as it would in the water.
By separating the driftwood from its original context and presenting it as sculpture in a stark gallery setting, Adam draws a parallel to the Resettlement Acts that took place in Newfoundland after it became Canada’s 10th province in 1949. Resettlement entailed the relocation of people from remote locations with few economic prospects to areas the Canadian government deemed to have more potential for growth. As a result, the people from the resettled areas left their communities and their land behind to start over in new locations.
In Driftwood, Adam examines the notion of displacement, questioning the changes that occur when something—or someone—is uprooted from its native environment. Here, the driftwood is geographically distant from the ocean, but the ocean remains its lifeblood, carrying it along on invisible waves.
| Doc | Purpose |
|---|---|
| CONTRIBUTING.md | How to set up, develop, and submit changes |
| SECURITY.md | Reporting vulnerabilities and what not to commit |
| CHANGELOG.md | Notable project changes |
| viz/README.md | Optional browser visualization |
From the Pi (clones from GitHub):
curl -fsSL https://raw.githubusercontent.com/adamsimms/driftwood/master/deploy/install.sh | bashOr from a local checkout:
./deploy/install.sh --from-sourceDeploy the repo to /home/pi/driftwood on the Pi.
Requirements: Python 3.10+, Raspberry Pi OS (or similar Linux) on the Pi. Tested with Raspberry Pi 3 Model B.
flowchart LR
TideAPI[CHS IWLS API] --> DataStream[live_data_stream.py]
WaveAPI[SmartAtlantic ERDDAP] --> DataStream
DataStream --> CSV[data/tide_data.csv + wave_status.csv]
CSV --> Motors[project_log_live.py]
Motors --> Slush[SlushEngine + stepper motors]
Gallery[gallery_timings.py] --> Motors
scripts/live_data_stream.py— polls external APIs and writes CSV files todata/scripts/project_log_live.py— thin entry point; motor logic lives inmotor_*.pyscripts/check_apis.py— verify tide and wave data sourcesscripts/play_test.py— manual motor positioning for calibrationviz/— optional WebGL ocean simulation (browser only, not used by the Pi)
| Data | Source | Default |
|---|---|---|
| Tide | CHS Integrated Water Level System (IWLS) | Bonavista (station 00990) |
| Waves | SmartAtlantic ERDDAP | Holyrood Buoy 2 |
Note: The original Mouth of Placentia Bay buoy dataset was decommissioned in 2022. The default wave source is the nearest active SmartAtlantic buoy (Holyrood Buoy 2). Change
WAVE_ERDDAP_DATASETinconfig/data_input.pyto use another dataset if needed.
Install the SlushEngine Python library separately — it requires the motor driver hardware.
If you have not run the install step yet, do that first.
Verify data sources:
cd ~/driftwood/scripts && python3 check_apis.pyStart live tide and wave data:
cd ~/driftwood/scripts && python3 live_data_stream.pyStart motors:
cd ~/driftwood/scripts && python3 project_log_live.pyConfigure log position manually in cm (e.g. -10,15):
cd ~/driftwood/scripts && python3 play_test.pySee what Python processes are running:
ps -ef | grep pythonEdit config/data_input.py on the Pi:
| Parameter | Description |
|---|---|
lowest_tide |
Motor steps from home to lowest tide position |
tide_range |
Motor steps between lowest and highest tide |
multiplier |
Scales wave motion amplitude |
speed_multiplier |
Scales motor speed (max ~2) |
data_refresh_interval |
Seconds between API polls in the data stream |
TIDE_STATION_ID |
CHS IWLS station ID (default: Bonavista) |
WAVE_ERDDAP_DATASET |
SmartAtlantic ERDDAP dataset (default: Holyrood Buoy 2) |
Gallery hours are defined in config/gallery_hours.py. Update GALLERY_HOURS for your venue schedule (weekday keys: Monday=0 … Sunday=6).
Copy the unit files and enable them:
sudo cp deploy/systemd/driftwood-data.service /etc/systemd/system/
sudo cp deploy/systemd/driftwood-motors.service /etc/systemd/system/
sudo systemctl daemon-reload
sudo systemctl enable driftwood-data driftwood-motors
sudo systemctl start driftwood-data driftwood-motorsCheck status:
sudo systemctl status driftwood-data driftwood-motors| Problem | Things to try |
|---|---|
check_apis.py tide fails |
Confirm network access; verify TIDE_STATION_ID in config/data_input.py; check IWLS API status |
check_apis.py wave fails |
The ERDDAP dataset may be offline or decommissioned — try another dataset from SmartAtlantic ERDDAP and update WAVE_ERDDAP_DATASET |
Empty or missing CSVs in data/ |
Run live_data_stream.py and wait for a successful fetch; check check_apis.py first |
| Motors do not move | Confirm SlushEngine is installed; run play_test.py for manual calibration; check motor power and wiring |
ModuleNotFoundError: Slush |
Install the SlushEngine Python library on the Pi |
| Gallery closed message | Update config/gallery_hours.py for your schedule |
| Permission errors on Pi | Ensure scripts run as the pi user; systemd units assume /home/pi/driftwood |
Schedule a cron task via crontab -e:
45 11 * * * sudo reboot
Configure network access on the Pi through your OS network manager (e.g. NetworkManager for eduroam). Do not commit credentials or machine-specific network config to this repo. See SECURITY.md.
- Raspberry Pi 3 Model B
- Raspberry Pi Power Supply 5V 3A (optional)
- SlushEngine
- Nema 23 Stepper Motor — Bipolar 340oz.in, 1.8A, 4.95V
- 2.1mm Barrel Jack to terminal
- 8mm Aluminum Key Hub w/ Set Screw
- 12VDC 3A Wall Adapter Power Supply
- Heat sinks