TechPower

FRC Team 334's post-match power review for FRC robots. Load a match's robot log and CANivore hoot logs to see battery sag, brownouts, whole-robot and per-motor current, motor temperature, and where the energy went.

Setup

Requires Python 3.10+.

pip install -r requirements.txt
python app.py          # → http://localhost:5000

Example logs are stored with Git LFS. If an example fails to open with a "Git LFS pointer" error, run git lfs pull.

Logs

Upload up to three .wpilog files from one match:

File	Pattern	Needed for
Robot log	FRC_*.wpilog	Required: battery voltage, PDH current, brownouts, match phases
Swerve CANivore	*_CC<serial>_<date>.hoot.wpilog	Swerve motor current / voltage / temperature
Subsystems CANivore	*_01<serial>_<date>.hoot.wpilog	Subsystem motor data

Hoot files must be converted to .wpilog first (Phoenix Tuner / owlet). The two-character prefix after the match name picks the bus (prefix_map in config.json).

Hoot logs run on the CANivore's clock, so TechPower shifts them onto the robot log's clock by matching the first robot-enable edge in each. If the robot never enabled, a warning is shown.

Using the dashboard

• Drag along the timeline bar to scrub. Click any chart to jump there.
• Drag across a chart to zoom into that span. The − / + buttons (or keys) zoom around the cursor; Ctrl + scroll and pinch also zoom. Double-click or Esc shows the whole match.
• Space plays, arrow keys step 1 s (Shift: 5 s).
• Click motors in Values at cursor to compare up to four in the motor charts.
• Click the brownout count to jump to the next brownout.
• The Field panel shows where the robot was at the cursor (Pose2d, blue origin, same view as AdvantageScope), with a 5 s trail shaded by current draw, the planned auto path, and red rings where brownouts happened. Select a ring to jump to it.
• Brownouts lists every brownout with its depth, the robot's draw and the three motors pulling the most supply current; select one to jump to it.
• Example matches can be linked directly: /#example=Q17&tab=energy.

Metrics

• Battery resistance / resting voltage — fitted from voltage sag vs. PDH current (with the PDH's CAN reporting lag removed). Includes main wiring, so compare across matches to spot weak batteries.
• Charge used (Ah) and energy (Wh) — whole robot, by match phase, and per motor (net of regen).
• Time under 8 V — how long the robot spent sagging toward brownout.
• RMS supply current / time over breaker per motor — what heats wiring and trips 40 A breakers; a sign supply current limits are too high.

Configuration

config.json maps log keys and motors:

• log_sources.wpilog.keys — robot-log entry names, including pose (struct:Pose2d), chassis_speeds and auto_trajectory (struct:Pose2d[]). Battery current comes from the PDH TotalCurrent (the SystemStats BatteryCurrent entry is only the roboRIO's own draw).
• log_sources.hoot.signal_keys — Phoenix 6 TalonFX signal names.
• thresholds — sag_voltage for the "time under" readout, breaker_amps for the per-motor "over breaker" time (match your PDH breakers).
• field — field image and its pixel calibration (copied from AdvantageScope's field config, scaled to the shipped image), and robot bumper size for drawing.
• motors — one entry per TalonFX: CANivore bus, CAN ID, PDH channel, subsystem.

API

Route	Method	Description
/	GET	Dashboard
/api/analyze	POST	Analyze uploaded logs (multipart field logs, 1–3 files)
/api/example/<id>	GET	Analyze a bundled example session (e.g. Q17)

Errors come back as {"error": "..."} with a 4xx/5xx status. Results are cached in memory, so reopening a match is instant.

TODO

• Video player
• View subsystem (hoot -> wpilog)
• AdvantageScope-style timeline

Credits

The 2026 field image comes from AdvantageScope by FRC 6328; see static/img/FIELD_LICENSE.txt.