Using the data logger

You interact with the BODAQS data logger using a keypad and small display on the device. Optionally, you can connect a handlebar-mounted switch to make on-bike interaction more convenient. To download files or do detailed configuration, the device connects to WiFi and you access it from a web browser.

Display overview

The logger’s display shows current logger status and supports configuring and calibrating the logger through a menu system. The display shows the idle/status screen unless the menu is open.

The idle/status screen shows:

• In the top row, the current status. When not logging, this row shows the WiFi state.
• The sample rate.
• The number of active sensor channels.
• In the bottom row, the time and battery charge state.

When logging is active, the main idle information blinks periodically providing visible indication that the logger is recording. (If you are using the bar switch, the LED on the switch is also on to indicate logging).

Short messages appear in the middle of the screen after actions such as starting a log, stopping a log, marking an event, saving calibration, or encountering an error.

The OLED dims after a period of inactivity to save power. Using the controls wakes it back to normal brightness.

Navigation model

The user interface uses a simple menu model:

• Move up and down to change the highlighted row.
• Select or navigate right on the highlighted row to enter a submenu or apply an action.
• Navigate left to return to the previous screen.
• Navigate right from the idle/status screen to enter the menu. Navigate left from the top-level menu to return to the idle/status screen.

The selected row is shown with a leading > marker.

If a menu has more rows than can fit on the display, the visible list scrolls as you move through it.

The menu closes automatically after a period of inactivity. If that happens, reopen the menu and continue from the top-level screen.

Logging

Logging is of course the main function of the data logger. When logging starts, the logger creates a new log file on the SD card and begins recording samples from the active sensors at the set sample rate.

Starting a log

Start logging by pressing the ‘sel’ (middle) button on the logger when in the idle scree. Starting logging will stop WiFi and the web server if they are running. The logger shows Log start if the run starts successfully. If you are using the bar switch, a long press will toggle logging on.

Stopping a log

Pressing the ‘sel’ button again stops stops logging, closes the current log file, restores normal controls, and shows a Log stop confirmation. If WiFi was active when the log was started, the logger will attempt to restore the connection. If you are using the bar switch, a long press will toggle logging off.

Marking events

When logging is active, the user can mark an event of interest. A mark is written into the log stream so the event can be found later during analysis. Typical uses might include:

• Beginning or ending a test section
• A trail feature of interest
• Noting unusual or interesting bike behaviour during a run.

The display shows Marked when a mark is logged.

Requires bar switch

Marks are logged by a short press of the bar switch, if you have one. For safety reasons you cannot log marks using the logger keypad.

Main menu

The main menu provides access to on-device settings and actions. The top-level items are:

• WiFi: ON, WiFi: OFF, or WiFi: CONNECTING: toggles WiFi on and off
• Mute sensors: allows activation and deactivation of sensors
• Sample rate: <rate> Hz: sets the logger sample rate
• Calibration: runs calibration actions for sensors.
• Sleep: powers the logger down.
• Reset time: forces a re-sync of the real-time clock (RTC)
• Restart: re-boots the logger.

WiFi and web interface

Selecting or navigating right from the WiFi menu item starts or stops WiFi and the web interface. If using the bar switch, a double press on the switch will also toggle WiFi on or off.

When WiFi is off, selecting the row starts a connection attempt. The display changes to WiFi: CONNECTING while the logger tries to connect. If the connection succeeds and the web server starts, the row changes to WiFi: ON.

When WiFi is on, selecting the row stops the web server and disables WiFi. The row changes back to WiFi: OFF.

The idle screen shows WiFi status in the top row, including the name of the network and the logger’s IP address.

Network selection

The logger allows configuration of up to 5 WiFi networks. When connecting, it will prioritise the most network it was connected to, so long as it has sufficient signal.

Logging has priority

WiFi and logging are interlocked. The logger will not start the web server while logging is active. If WiFi is running when logging starts, it is stopped so that sampling has priority.

If WiFi cannot start, the display shows a short failure message such as WiFi fail or WiFi timeout.

Mute sensors

The Mute sensors menu opens a list of configured sensors. This screen lets you enable or mute individual sensor channels without editing the configuration file.

Each sensor appears by name. Muted sensors show [M] beside the name.

Selecting a sensor toggles it between muted and active:

• Muted means the sensor is excluded from active logging output.
• Active sensors are included in the channel count and log data.

The display shows a short Muted or Unmuted confirmation after the change.

Sample rate

The Sample rate menu opens a list of supported sample rates.

Supported rates range from 10Hz to 1000Hz. The current rate is shown with [*]. Other available rates are shown with [ ].

Select a rate to apply it. The logger saves the new rate and returns to the main menu after showing a confirmation such as Rate: 500 Hz.

Calibration

The Calibration menu exposes calibration helpers that are specific to the type of sensor. For linear motion-type sensors, ZERO and RANGE calibration methods are supported.

The first calibration screen lists the configured sensors. Each row shows the sensor name and the calibration operations available for that sensor:

• [Z] means zero calibration is available.
• [R] means range calibration is available.
• [Z|R] means both zero and range calibration are available.
• [none] means the sensor does not currently expose on-device calibration actions.

Select a sensor to open its calibration detail screen.

Range calibration

Range calibration captures the sensor’s travel range between a start position and a finish position.

Typical range calibration workflow:

1. Put the sensor or suspension component at the range start position.
2. Open Calibration.
3. Select the sensor.
4. Select Start RANGE.
5. Move the sensor or suspension component through the intended travel to the finish position.
6. Select Finish RANGE.
7. Check the captured count shown on the display.
8. Select Save to keep the range, or Cancel to discard it.

While range calibration is active, the display shows live raw counts at the bottom of the screen. This helps confirm that the sensor is moving and that the logger is seeing the change.

Saving a range calibration writes the range values to the logger configuration. For sensors where direction matters, the logger also updates the sensor’s inversion setting based on the captured start and finish positions.

Range calibration definitely needed

Range calibration is important because it lets the logger translate sensor output into real-world units (like mm of travel). It should only have to be done once per sensor and can be done with the sensor off the bike - no letting air out or removing springs. Rejoice!

Zero calibration

Zero calibration captures the sensor’s current raw position and saves it as the installed zero point.

Typical zero calibration workflow:

1. Put the sensor or suspension component at the desired zero/reference position.
2. Open Calibration.
3. Select the sensor.
4. Select Zero.
5. Check the captured count shown on the display.
6. Select Save to keep the value, or Cancel to discard it.

After a zero capture, the display briefly shows the captured raw count. Saving writes the new calibration to the logger configuration.

Do I need to zero?

Having an accurately-set zero point is only necessary if you are applying output transformations in the logger - for example, if you are measuring shock movement and want the logger to output wheel movement. If you are not applying a transformation (say, for a fork) or you intend to do the transformation in the analysis software, the zero point can be detected automatically in the analysis software.

More on this topic in [link to transformations]

Sleep

The Sleep menu item puts the logger into sleep mode. Use sleep when you want to conserve battery without fully disconnecting power. The logger will wake up when ‘sel’ is pressed.

A long press on the nav-left button from the idle screen will also put the logger to sleep.

Proto-E funny

One of the foibles of the Proto-E PCB design is that the analog rail’s power supply is connected directly to the battery and is always on. If you leave the logger unattended for long enough, it will completely drain (and thereby kill) the battery. This is what is known as ‘not good design’ and is fixed in Proto-F and later PCBs. The work-around is to leave your logger plugged in to a charger when not in use.

Reset time

The Reset time menu item forces a time sync using WiFi.

When the logger boots, it attempts to connect to WiFi to set its internal real-time clock. If it cannot find a network connection, the clock status will remain not set. If this occurs, you can force a sync once you have WiFi access.

If the sync starts, the menu row changes to Time: SYNCING. If the sync fails, the display shows Time sync fail.

Restart

The Restart menu item restarts the firmware.

Use restart after configuration changes or if the logger is in an unexpected state. Restart is blocked while logging is active, so stop the current log first.