Class BatteryLogger

java.lang.Object

frc.spectrumLib.telemetry.BatteryLogger

public class BatteryLogger
extends Object

Tracks and logs current draw, power, and cumulative energy consumption across subsystems each robot loop cycle.

Key derivation (splitting a channel name into its parent keys) and log-key construction are cached per channel name, so steady-state operation performs no string splitting or concatenation. The set of channel names is small and fixed after the first loop.

Current is published at 10 Hz (Telemetry.slowLogThisLoop()) and power and energy at SLOW_LOG_PERIOD_SECONDS. This class produced the most log records on the robot, and the loop period grows almost linearly with log volume. In the 2026-09-05 18:38 log it accounted for 32.3 of the 94 records written per loop, a third of everything, while the loop ran at 33 Hz with a median period of 27.4 ms. Current is the channel worth watching live. Power is current times pack voltage and energy is its integral, so neither needs 50 Hz to stay useful.

Constructor Summary

Constructors

Constructor	Description
BatteryLogger()

Method Summary

Modifier and Type	Method	Description
double	getTotalCurrent()	Running total of current draw accumulated since the last logPower() call, in amps.
double	getTotalEnergy()	Cumulative energy consumed over the entire enabled session, in joules.
double	getTotalPower()	Total power drawn on the most recent logPower() call, in watts.
void	logPower()	Appends control-overhead current consumers (roboRIO, CANcoders, Pigeon, CANivore, radio), integrates energy over the elapsed loop, then logs current every loop and power and energy every SLOW_LOG_PERIOD_SECONDS.
void	reportCurrentUsage(String key, double... amps)	Records the current draw for a named subsystem channel and accumulates it into the running totals.
void	setBatteryVoltage(double batteryVoltage)	Battery terminal voltage used to convert current to power, in volts.
void	setEnabled(boolean enabled)	When false all methods are no-ops, allowing the logger to be disabled at runtime.
void	setRioCurrent(double rioCurrent)	Estimated current drawn by the RoboRIO itself, in amps.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

BatteryLogger

public BatteryLogger()

Method Details

reportCurrentUsage

public void reportCurrentUsage(String key,
 double... amps)

Records the current draw for a named subsystem channel and accumulates it into the running totals. The key may use "/" or "-" as separators; parent keys are automatically aggregated.

Power and energy are computed from these currents in logPower(), which knows this loop's pack voltage and its true elapsed time.

Parameters:

key - Hierarchical name for the current consumer (e.g. "Drive/FrontLeft")

amps - One or more current readings in amps; absolute values are summed

logPower

public void logPower()

Appends control-overhead current consumers (roboRIO, CANcoders, Pigeon, CANivore, radio), integrates energy over the elapsed loop, then logs current every loop and power and energy every SLOW_LOG_PERIOD_SECONDS. Resets the per-loop current accumulators afterward; cumulative energy is preserved across calls.

setEnabled

public void setEnabled(boolean enabled)

When false all methods are no-ops, allowing the logger to be disabled at runtime.

getTotalCurrent

public double getTotalCurrent()

Running total of current draw accumulated since the last logPower() call, in amps.

getTotalPower

public double getTotalPower()

Total power drawn on the most recent logPower() call, in watts.

getTotalEnergy

public double getTotalEnergy()

Cumulative energy consumed over the entire enabled session, in joules.

setBatteryVoltage

public void setBatteryVoltage(double batteryVoltage)

Battery terminal voltage used to convert current to power, in volts.

setRioCurrent

public void setRioCurrent(double rioCurrent)

Estimated current drawn by the RoboRIO itself, in amps.