Downloading and Analyzing Data Logs in Mission Planner

Dataflash logs are stored on the autopilot and can be download after a flight. By default, they are created after you first arm the vehicle. This topic explains how to configure and access Dataflash logs.

Depending on the autopilot type and configuration, the dataflash logs may be saved on a SD card, dataflash chip or streamed over MAVLink telemetry ports. The MAVLink option does require a high-speed telemetry port, typically 921600 baud.

Note

Telemetry logs (also known as “tlogs”) collect similar information to dataflash logs (see Diagnosing problems using Logs for more information).

Note

If your vehicle is having trouble producing dataflash logs - including the infamous “No IO heartbeat” diagnostic message - try a different SD card. You may also choose to test the card using a dedicated tool, such as H2testw. Low board voltages are also known to cause logging issues.

Logging Parameters

Some commonly used parameters are:

  • LOG_BACKEND_TYPE: Bitmask for where to save logs to. Common values are “0” to disable logging, “1” to log to SD card file, “2” to stream over MAVLink and “4” to log to board dataflash memory, if equipped.

  • LOG_BITMASK: Bitmask for what items are logged. Normally, use default value, or “0” to disable logging.

  • LOG_DISARMED: Setting to one will start logging when power is applied, rather than at the first arming of the vehicle. Usefull when debugging pre-arm failures.

  • LOG_FILE_DSRMROT: Setting this bit will force the creation of a new log file after disarming, waiting 15 seconds, and then re-arming. Normally, a log will be one file for every power cycle of the autopilot, beginning upon first arm.

  • LOG_FILE_MB_FREE: This parameter sets the minimum free space on the logging media before logging begins. If this is not available, then older logs will be deleted to provide it during initialization. Default is 500MB.

  • LOG_FILE_RATEMAX: This sets the maximum rate that streaming log messages will be logged to the file backend to limit file sizes. A value of zero(default) means no limit is applied to normal logging, which depends on the SCHED_LOOP_RATE value ( 50Hz: Plane, 300Hz: QuadPlane/Rover, 400Hz: Copter, normally). Note that similarly, LOG_BLK_RATEMAX and LOG_MAV_RATEMAX perform the same optional limiting for the BLOCK logging and MAVLink logging streams, respectively.

Note

If you suspect that you are missing logging entries due to excessive logging speed, you can check the DSF.Dp log message for the amount of missed entries.

Note

Logging of the continuously streaming log messages, such as attitude, sensors, etc. can be paused by using the RCx_OPTION auxiliary function “164” on a transmitter channel. Switching this channel high will pause these messages, but not events, mode changes, warnings, etc. This allows autopilots with limited logging capabilites (ie using Block logging to chip memory and no SD card) to log only when desired during the flight, as during tuning phases or determination of TECs parameters, etc. You can also eliminate unneeded log messages using LOG_BITMASK to reduce log size

Automatic Analysis of logs

../_images/MissionPlanner_AutomaticLogAnalysis_Buttons.png

Mission Planner: Start LogAnalysis

The simplest analysis is to generate a basic automated report that will highlight common problem areas. For that, click on “Log Analysis” and select a log that you’ve already saved to the MissionPlanner/logs directory. They will be in folders named after the vehicle type, such as QUADCOPTER or ROVER. Once you pick the log you want, it will generate a report that looks like this:

../_images/Capture3.png

Manually review a log

For more detailed analysis, click on “Review a Log” and select a log that you’ve already saved to the MissionPlanner/logs directory. Once again, they will be in folders named after the vehicle type, such as QUADCOPTER or ROVER.

Steps to review a log downloaded from the internet, or your vehicle

For DataFlash logs, with a .bin or .log extension:

  1. Download the log file. Note the place on your computer to which it is downloaded. (For example, it might be C:\Downloads)

  2. Open Mission Planner

  3. Navigate to the “Flight Data” page (top left)

  4. Select the “Dataflash Logs” tab (mid-screen, left side)

  5. Select the “Review a Log” button.

  6. A standard Windows “select a file” box will let you go find the .bin file that you downloaded, at the place that you downloaded it. (Per the example above, it is in C:\Downloads) Choose that file.

  7. After reading the log, a Manual Log Review window will be open, which allows you to plot data from the log for inspection. (see below)

Reviewing the log data

Once you pick the log you want, you will get charts such as the below. The basic format of the dataflash is:

  • Line numbers appear on the very left side of the viewer

  • Software version and board type appear at the top

  • FMT messages are next which tell the mission planner the column headers for each message type

  • PARM rows which show each parameter (in the order in which they appear in the eeprom) along with their value at the beginning of the flight

  • Flight data messages including GPS, IMU, etc.

../_images/mp_dataflash_format.png

Graph any flight data by first clicking on the appropriate row, you should see the column headers update appropriately. Next find the column you wish to graph, click on it and then push the “Graph this data” button. In the example above the ATT’s Roll-In and Roll data have been graphed. The mouse’s scroll wheel can be used to zoom in or out. You may also select an area of the graph to zoom in on it. Zoom out by right-mouse-button clicking and selecting “Set Scale to Default”. Here’s a mini tutorial on using this feature. You may also filter on just the first column (the flight data message type) by clicking on the first column and selecting the message type from the drop-down. This is very useful especially for viewing the different flight modes (called “MODE” messages) used during the mission. Click the first column again but press “Cancel” to clear the filter.

../_images/MissionPlanner_CLI_openDataflashFilter.png

Setting what data you want recorded

The LOG_BITMASK parameter controls what messages are recorded in the logs. The bits differ between vehicles. The image above is for Copter.

../_images/mp_dataflash_log_bitmask.png

Bitmask Table (Rover)

Bit

BitMask Name

What is logged if bit is set

0

Fast Attitude

Attitude @ 400Hz

1

Medium Attitude

Attitude @ 10Hz

2

GPS

GPS

3

System Performance

CPU,etc. Performance monitoring

4

Throttle

Throttle/Speed Control Data

5

Navigation Tuning

Navigation Data

7

IMU

IMU (ACC/Gyro) Data

8

Mission Commands

Mission/GCS Commands

9

Battery Monitor

Battery Monitors Data

10

Rangefinder

Rangefinder Data (if present)

11

Compass

Compasses Data

12

Camera

Camera Data (if present)

13

Steering

Steering rates and targets

14

RC Input & Output

RC input/Servo output data

19

Raw IMU

Raw IMU data, unprocessed

20

Video Stabilization

GyroFlow Data logs

ATTITUDE logging will occur at highest rate of the selections.

Note

the logging of EKF3 data is controlled by the EK3_LOG_LEVEL parameter.

Message Details (Copter specific)

Note

Many messages are detailed in the Onboard Message Log Messages page in each vehicle’s wiki section.

ATT (attitude information):

DesRoll

The pilot’s desired roll angle in degrees (roll left is negative, right is positive)

Roll

The vehicle’s actual roll in degrees (roll left is negative, right is positive)

DesPitch

The pilot’s desired pitch angle in degrees (pitch forward is negative, pitch back is positive)

Pitch

The vehicle’s actual pitch angle in degrees (pitch forward is negative, pitch back is positive)

DesYaw

The pilot’s desired heading in degrees with 0 = north

Yaw

The vehicle’s actual heading in degrees with 0 = north

ErrRP

The average size of the roll/pitch error estimate (values between 0 and 1)

ErrYaw

The average size of the yaw error estimate (values between 0 and 1)

ATUN (auto tune overview):

Axis: 0 = Roll, 1 = Pitch

TuneStep

0 = Returning towards Level (before or after a test), 1 = Testing (i.e. performing a twitch to test response), 2 = Updating gains (twitch completed and gains adjusted)

RateMin

Minimum recorded rate during this test

RateMax

Maximum recorded rate during this test

RPGain

Rate P gain value being tested

RDGain

Rate D gain value being tested

SPGain

Stabilize P gain being tested

ATDE (auto tune step details):

Angle

Angle of the copter in centi-degrees for the axis being testedx

Rate

Rate of rotation of the copter for the axis being tested

CAM (time and position when camera shutter was activated):

GPSTime

The GPS reported time since epoch in milliseconds

Lat

The accelerometer + GPS latitude estimate

Lng

The accelerometer + GPS longitude estimate

Alt

The accelerometer + barometer estimated altitude in cm above ground

Roll

The vehicle roll angle in centi-degrees

Pitch

The vehicle pitch angle in centi-degrees

Yaw

The vehicle’s heading in centi-degrees

CMD (commands received from the ground station or executed as part of a mission):

CTot

The total number of commands in the mission

CNum

This command’s number in the mission (0 is always home, 1 is the first command, etc)

CId

The MAVLink message id

Copt

The option parameter (used for many different purposes)

Prm1

The command’s parameter (used for many different purposes)

Alt

The command’s altitude in meters

Lat

The command’s latitude position

Lng

The command’s longitude position

COMPASS (raw compass, offset and compassmot compensation values):

Field

Description

MagX, MagY. MagZ

Raw magnetic field values for x, y and z axis

OfsX, OfsY, OfsZ

Raw magnetic offsets (will only change if COMPASS_LEARN parameter is 1)

MOfsX, MOfsY, MOfsZ

Compassmot compensation for throttle or current

CURRENT (battery voltage, current and board voltage information):

FIELD

DESCRIPTION

Thr

Pilot input throttle from 0 ~ 1000

ThrInt

Integrated throttle (i.e. sum of total throttle output for this flight)

Volt

Battery voltage in volts * 100

Curr

Current drawn from the battery in amps * 100

Vcc

Board voltage

CurrTot

Total current drawn from battery

CTUN (Control, Throttle and altitude information):

FIELD

DESCRIPTION

TimeUS

Time stamp for messages in microseconds (can be ignored)

ThI

The pilot’s throttle in as a number from 0 to 1000

ABst

Angle Boost: throttle increase (from 0 ~ 1000) as a result of the copter leaning over (automatically added to all pilot and autopilot throttle to reduce altitude loss while leaning)

ThO

Final throttle output sent to the motors (from 0 ~ 1000). Normally equal to ThrI+ABst while in stabilize mode.

ThH

Estimated throttle required to hover throttle in the range 0 ~ 1

DAlt

The Desired Altitude while in AltHold, Loiter, RTL or Auto flight modes. It is influenced by EKF origin, which in 3.5.X is corrected by GPS altitude. This behaviour is turned off in 3.6.X and can be turned on with EKF_OGN_HGT_MASK.

Alt

The current EKF Altitude

BAlt

Barometer Altitude: The altitude above ground according to the barometer

DSAlt

Desired distance in cm from ground or ceiling (only visible if Sonar is available)

SAlt

Sonar Altitude: the altitude above ground according to the sonar (Only visible of Sonar is available)

TAlt

Terrain altitude (not used by default)

DCRt

Desired Climb Rate in cm/s

CRt

Climb Rate in cm/s

N

Harmonic notch current center frequency for gyro in Hz

D32, DU32 (single data values which are either signed 32bit integers or unsigned 32bit integers):

FIELD

DESCRIPTION

id

Identification number for the variable. There are only two possible values:

  • 7 = bit mask of internal state (The meaning of individual bits can be found in the def’n of the ap structure

  • 9 = simple mode’s initial heading in centi-degrees

EKF (Extended Kalman Filter):

Log information here (Dev Wiki). Overview here.

ERR (an error message):

SubSystem and Error codes listed below

Subsys ECode and Description
2 = Radio
  • 0 = Errors Resolved

  • 2 = Late Frame : no updates received from receiver for two seconds

3 = Compass
  • 0 = Errors Resolved

  • 1 = Failed to initialise (probably a hardware issue)

  • 4 = Unhealthy : failed to read from the sensor

5 = Radio Failsafe
  • 0 = Failsafe Resolved

  • 1 = Failsafe Triggered

6 = Battery Failsafe
  • 0 = Failsafe Resolved

  • 1 = Failsafe Triggered

8 = GCS Failsafe
  • 0 = Failsafe Resolved

  • 1 = Failsafe Triggered

9 = Fence Failsafe
  • 0 = Failsafe Resolved

  • 1 = Altitude fence breach, Failsafe Triggered

  • 2 = Circular fence breach, Failsafe Triggered

  • 3 = Both Alt and Circular fence breached, Failsafe Triggered

  • 4 = Polygon fence breached, Failsafe Triggered

10 = Flight mode Change failure

Vehicle was unable to enter the desired flight mode normally because of a bad position estimate

See flight mode numbers here

11 = GPS
  • 0 = Glitch cleared

  • 2 = GPS Glitch occurred

12 = Crash Check
  • 1 = Crash into ground detected. Normally vehicle is disarmed soon after

  • 2 = Loss of control detected. Normally parachute is released soon after

13 = Flip mode 2 = Flip abandoned (not armed, pilot input or timeout)
15 = Parachute
  • 2 = Not Deployed, vehicle too low

  • 3 = Not Deployed, vehicle landed

16 = EKF Check
  • 0 = Variance cleared (position estimate OK)

  • 2 = Bad Variance (position estimate bad)

17 = EKF Failsafe
  • 0 = Failsafe Resolved

  • 1 = Failsafe Triggered

18 = Barometer
  • 0 = Errors Resolved

  • 4 = Unhealthy : failed to read from the sensor

19 = CPU Load Watchdog
  • 0 = Failsafe Resolved

  • 1 = Failsafe Triggered (normally vehicle disarms)

20 = ADSB Failsafe
  • 0 = Failsafe Resolved

  • 1 = No action just report to Pilot

  • 2 = Vehicle avoids by climbing or descending

  • 3 = Vehicle avoids by moving horizontally

  • 4 = Vehicle avoids by moving perpendicular to other vehicle

  • 5 = RTL invoked

21 = Terrain Data 2 = missing terrain data
22 = Navigation
  • 2 = Failed to set destination

  • 3 = RTL restarted

  • 4 = Circle initialisation failed

  • 5 = Destination outside fence

23 = Terrain Failsafe
  • 0 = Failsafe Resolved

  • 1 = Failsafe Triggered (normally vehicle RTLs)

24 = EKF Primary changed
  • 0 = 1st EKF has become primary

  • 1 = 2nd EKF has become primary

25 = Thrust Loss Check
  • 0 = Thrust Restored

  • 1 = Thrust Loss Detected (altitude may be prioritised over yaw control)

26 = Sensor Failsafe (Sub)
  • 0 = Sensor Failsafe Cleared

  • 1 = Sensor Failsafe Triggered

27 = Leak Failsafe (Sub)
  • 0 = Leak Failsafe Cleared

  • 1 = Leak Detector Failsafe Triggered

28 = Pilot Input Timeout Failsafe (Sub only)
  • 0 = Pilot Input Failsafe Cleared

  • 1 = Pilot Input Failsafe Triggered

29 = Vibration Failsafe
  • 0 = Excessive Vibration Compensation De-activated

  • 1 = Excessive Vibration Compenstaion Activated

EV: (an event number). The full list of possible events can be found in AP_Logger.h but the most common are:

Event No

DESCRIPTION

10

Armed

11

Disarmed

15

Auto Armed (pilot has raised throttle above zero and autopilot is free to take control of throttle)

18

Land Complete

25

Set Home (home location coordinates have been capture)

28

Not Landed (aka Takeoff complete)

GPA: (Global Position Accuracy)

FIELD

DESCRIPTION

VDop

Vertical dilution of precision, a unitless measure of precision https://en.wikipedia.org/wiki/Dilution_of_precision

HAcc

Horizontal Accuracy as reported by the GPS module, in meters

VAcc

Vertical Accuracy as reported by the GPS module, in meters

SAcc

Speed accuracy as reported by the GPS, in m/s/s

VV

Flag to indicate if the GPS is reporting vertical velocity

0 No vertical velocity data 1 GPS has vertical velocity data

SMS

The autopilot time in milliseconds that the accuracy/GPS position data is associated with.

Delta

The time between when the previous GPS message and the current GPS message was parsed by the autopilot, in milliseconds

GPS:

FIELD

DESCRIPTION

Status

0 = no GPS, 1 = GPS but no fix, 2 = GPS with 2D fix, 3 = GPS with 3D fix

Time

The GPS reported time since epoch in milliseconds

NSats

The number of satellites current being used

HDop

A measure of gps precision (1.5 is good, >2.0 is not so good) https://en.wikipedia.org/wiki/Dilution_of_precision

Lat

Latitude according to the GPS

Lng

Longitude according to the GPS

RelAlt

Accelerometer + Baro altitude in meters

Alt

GPS reported altitude (not used by the autopilot)

SPD

Horizontal ground speed in m/s

GCrs

Ground course in degrees (0 = north)

IMU (accelerometer and gyro information):

FIELD

DESCRIPTION

GyrX, GyrY, GyrZ

The raw gyro rotation rates in radians/second

AccX, AccY, AccZ

The raw accelerometer values in m/s/s

Mode (flight mode):

FIELD

DESCRIPTION

Mode

The flight mode displayed as a string (i.e. STABILIZE, LOITER, etc)

ThrCrs

Throttle cruise (from 0 ~ 1000) which is the autopilot’s best guess as to what throttle is required to maintain a stable hover

Rsn

Reason for mode change (TX command, failsafe, etc) . The meaning of code values can be found in ModeReason

NTUN (navigation information):

FIELD

DESCRIPTION

WPDst

Distance to the next waypoint (or loiter target) in cm. Only updated while in Loiter, RTL, Auto.

WPBrg

Bearing to the next waypoint in degrees

PErX

Distance to intermediate target between copter and the next waypoint in the latitude direction

PErY

Distance to intermediate target between copter and the next waypoint in the longitude direction

DVelX

Desired velocity in cm/s in the latitude direction

DVelY

Desired velocity in cm/s in the longitude direction

VelX

Actual accelerometer + gps velocity estimate in the latitude direction

VelY

Actual accelerometer + gps velocity estimate in the longitude direction

DAcX

Desired acceleration in cm/s/s in the latitude direction

DAcY

Desired acceleration in cm/s/s in the longitude direction

DRol

Desired roll angle in centi-degrees

DPit

Desired pitch angle in centi-degrees

PM (performance monitoring):

FIELD

DESCRIPTION

NLon

Number of long running main loops (i.e. loops that take more than 20% longer than they should according to SCHED_LOOP_RATE - ex. 3ms for 400Hz rate)

NLoop

The total number of loops since the last PM message was displayed. This allows you to calculate the percentage of slow running loops (which should never be higher than 15%). Note that the value will depend on the autopilot clock speed

MaxT

The maximum time that any loop took since the last PM message. This shouldn’t exceed 120% of scheduler loop period, but will be much higher during the interval where the motors are armed

Mem

Available memory, in bytes

Load

Percentage (times 10) of the scheduler loop period when CPU is used

RCOUT (pwm output to individual RC outputs):

RC1, RC2, etc : pwm command sent from autopilot to the esc/motor/RC output

Viewing KMZ FILES

When you download the dataflash log files from the autopilot it will automatically create a KMZ file (file with extension .kmz). This file can be opened with Google Earth (just double click the file) to view your flight in Google Earth. Please see the instructions on the Telemetry Logs Page for additional details.

Video tutorials