Data Logging

The microDRIVE LP units have automatic logging built-in, with a configurable rate. The log is circular, so it is constantly available for data acquisition and the oldest data being overridden. A completely full log can take 20-40 seconds to download off the microDRIVE over USB and several minutes over CAN bus.

Once loaded, they can be saved to a CSV or viewed with the log chart viewer. CSVs should be downloaded and sent for analysis when required. The configuration tool also supports an automatic upload feature to send files to the Hargrave team for further analysis and troubleshooting. The downloaded CSV will also store the configuration applied to the unit during log retrieval, including settings and firmware version.

Logged data is cleared between successful firmware updates by the unit automatically and when the logging rate is changed. Certain logging data fields can be disabled, this will increase the number of data points that can be logged before being overridden. Toggling a logging data field on or off will cause the logs to be cleared when the unit restarts.

Logged Data

The following data is logged, which may vary between firmware versions, along with a description:

Data Point	Unit	Description
Bus Voltage	Volts	The measured input voltage to the ESC.
Bus Current	Amps	The measured input current to the ESC.
Bridge Temperature	Degrees C	The temperature of the 3-phase bridge. This is the primary heat source with the ESC.
Electrical RPM	RPM	The current applied speed of the motor as electrical RPM. When viewing in the configuration tool it is displayed as mechanical RPM using the configured motor pole pairs.
Input Duty Cycle	%	The requested duty cycle, as reported by the input signal system, regardless of signal input type.
Output/Motor Duty Cycle	%	The current applied duty cycle to the 3-phase bridge. If this does not equal the input duty cycle, the ESC is actively limiting the output.
Phase Current	Amps	The output current to the 3-phase bridge. This is always higher than the bus current and should remain within the ESC limits.
Power	Watts	The measured input power to the ESC.
Voltage Ripple Deviation	%	The voltage ripple measured on the input to the ESC. Under steady-state loads, this should be below +-5% of the bus voltage. A higher voltage ripple is an indicator the system requires more input capacitance.
MCU Temperature	Degrees C	The measured temperature of the main processor within the ESC.
Motor Temperature	Degrees C	The measured temperature of the connected motor. Requires a motor with a compatible sensor (NTC or PTC).
Unit Uptime	Milliseconds	The time in ms since the unit powered on.

Recorded Status Flags

The unit stores several boolean flags inside bit-fields. These are parsed out into their boolean values by the configuration tool, the original bit-field values are stored for completeness but can be ignored.

The following status flags are recorded, which flags are present and their groupings will vary between firmware versions.

More advanced flags are hidden by default on the configuration tool. They can be viewed for assistance with diagnostics.

Status Flags

These flags indicate certain running states of the unit.

Flag Name	Description
Motor Started	The motor is currently running.
Motor Active Hold	The motor is parked and is actively being held in a stationary position with applied duty cycle.
Motor Parking	The motor is in the process of parking but has not yet parked.

Drive Warnings

These flags indicate warnings that can affect motor drive but may have not caused drive to be disabled.

Flag Name	Description
Bus Over Abs Voltage	The input bus is over the unit’s absolute voltage limit.
Bus Over Voltage	The input bus is over the unit’s configured voltage limit.
Bus Ripple Exceeded	Excess input voltage ripple is present.
Bus Under Voltage	The input bus is below the configured voltage limit.
Motor Saturated	The motor is approaching current saturation, motor output has been reduced for drive to remain reliable.
Over Temperature Limit	The unit is exceeding the configured over temperature limit.

Drive Errors

These flags indicate errors related to motor drive which have caused drive to stop.

Flag Name	Description
Bridge Over Abs Temperature	The absolute temperature limit is being exceeded.
Bus Voltage Abs High	The input bus is over the unit’s absolute voltage limit.
Bus Voltage User High	The input bus is over the unit’s configured voltage limit.
Bus Voltage User Low	The input bus is under the unit’s configured voltage limit.
HW Bridge Fault	A hardware fault was detected on the 3-phase bridge.

Device Flags

These flags cover errors and warnings that are not directly drive related.

Flag Name	Description
Ignore Factory Calibration	Saved calibration values are not being used, current and voltage readings may be less accurate.
Input Signal Lost	The throttle control signal is lost and drive has been stopped.
3V3 Brownout	The voltage on the 3.3V line deviated below acceptable levels.
3V3 Deviation	The voltage on the 3.3V line deviated outside the normal range.
Bootloader Error	An error was detected on the firmware, recovery or bootloader sections of memory. This will occur after a firmware update.
Calibration Corrupt	The saved calibration values on the unit were corrupted and cannot be used. Please contact the Hargrave Technologies team.
Can Buffer Out of Memory	The CAN sub-system encountered a low memory situation and is unable to process messages. If this occurs it is advised to review telemetry settings and bus traffic.
CAN Off	The CAN sub-system is in an off state due to encountering too many errors.
Corrupt Settings	The settings saved on the device were corrupted. Default values have been loaded but motor drive is disabled, please reset the settings on the configuration tool.
Error Flash Corrupt	The on device errors were corrupted and reset.
External Oscillator Failure	The primary device clock source has failed. This is indicative of unit failure. Please contact support.
External Oscillator Fallback	The unit has resorted to using the fallback clock source. Please contact support.
Firmware Corrupt	The firmware partition was corrupted and firmware was restored from the recovery partition.
Firmware Error	The system encountered an invalid state or configuration and has shut off drive.
Firmware Updated	The firmware of the device was updated on start-up.
Logging System Error	The logging system has encountered an error.
Logs Force Cleared at Boot	Due to a firmware update or logging configuration change the logging data was cleared.
Motor Temperature Error	The connected motor temperature sensor is returning invalid readings and is not operating correctly.
Recovery Corrupt	The recovery partition was corrupt and was overwritten with firmware.
Watchdog Overrun	A software crash was detected, causing unit to restart.

Bridge Limiters

These flags indicate that the firmware intervened to limit the motor duty cycle output or its rate of change to protect the system.

Flag Name	Description
Limiter: Bus Current Limit	Motor duty cycle is being restricted to not exceed the bus current limit.
Limiter: Phase Current Limit	Motor duty cycle is being restricted to not exceed the phase current limit.
Limiter: Ramp Down Rate	The motor duty cycle ramp has been limited from decreasing down faster than the ramp down rate.
Limiter: Ramp to Stop Rate	The motor duty cycle ramp has been limited from ramping down to a stop faster than the ramp to stop rate. This is the rate at which the duty cycle will decrease when zero duty cycle is requested.
Limiter: Ramp Up Rate	The motor duty cycle has been limited from increasing faster than the ramp up rate.
Limiter: Bus Regen Current	The rate of decrease of the motor duty cycle has been limited to prevent excessive regeneration current.
Limiter: Bus Voltage High	The rate of decrease of the motor duty cycle has been limited to prevent excessive regeneration current which could cause voltage spikes on the bus.
Limiter: Bus Voltage Low	The rate of increase of the motor duty cycle has been limited to 0. The duty cycle is unable to increase from the current value.
Limiter: Maximum RPM	The motor duty cycle has been limited to prevent the RPM limit from being exceeded.
Limiter: Minimum Duty	The motor duty cycle has been limited to not go below the configured minimum duty cycle.
Limiter: Motor Over Temp	The motor duty cycle is being restricted to prevent the motor exceeding the temperature limit.
Limiter: Over Temperature	The motor duty cycle is being restricted to prevent the motor controller temperature from exceeding the limit.
Limiter: Phase Regen Current	The rate of decrease of the motor duty cycle has been limited to prevent excessive regeneration current.

ESC Signal

These flags indicate the state of the ESC throttle signal.

Flag Name	Description
ESC Signal Acquired	The motor controller has a valid throttle signal.
ESC Signal Armed	The throttle signal to the motor controller is ‘armed’.
Arming Switch On	The secondary arming switch is in the ‘armed’ position.
DroneCAN Signal Acquired	The motor controller has a valid DroneCAN signal.
DroneCAN Signal Armed	The system has received a DroneCAN arming message within the timeout period.
Serial Signal Acquired	The motor controller has a valid serial throttle signal.

Advanced Flags

These flags are for more advanced troubleshooting.

Flag Name	Description
AFW Engaged	Regenerative braking/Active Freewheeling (AFW) is engaged.
Demag Immeasurable	The motor controller is unable to accurately measure demagnetization of the motor. If this flag is active under steady state conditions the motor may be unfit for the system.

Additional Data

There are additional field and status flags recorded that are only available to the Hargrave Technologies support team. Please contact us for further diagnostics support if required.