Adjusting Configuration File

This page describes the information about the configuration file

The DAQ-A contains a user-accessible micro SD (uSD) card which stores the sensor data log as well as a configuration file to adjust the DAQ-A settings.

If the configuration file is not found on the uSD card during system boot a new file will be created. If any parameters are missing on the uSD it will add the default parameters at boot.

If the logging is turned off and the uSD card is removed from the device, then the logging will only resume once the uSD card is reinserted and the configuration file is present. If the uSD or the configuration file is not present the logging will not resume.

Opening the Configuration File for Editing

You can easily edit the configuration file on your computer using most common text editing programs. On Windows OS an example is the included Notepad application. Simply open the file in the text editor, make your adjustments and save the file. The file extension should remain the same (.jsn).

Configuration File Parameters

Here is the default configuration file:

{
  "FIRMWARE": 1.0,
  "MODEL": "DAQ-A-SD",
  "SERIAL": "#############################################",
  "action_button_long": 1,
  "action_button_short": 1,
  "gps_interval": 0.25,
  "led_brightness": 10,
  "led_enabled": true,
  "log_events": [
    0,
    1,
    2
  ],
  "ls_autoexposure": true,
  "ls_integration_time": 20,
  "pwm_trigger_autostart": false,
  "pwm_trigger_interval": 3
}

Here are details about each parameter:

Parameter Name	Options	Description
FIRMWARE	values from hardware	The firmware version of the software running on the DAQ-A
MODEL	values from hardware	The DAQ-A model
SERIAL	values from hardware	The unique serial number for the DAQ-A
action_button_long	1	1 = start/stop data logging
action_button_short	1	1 = start/stop image capture
gps_interval	0.25 - ∞	Number of seconds between GPS log event
led_brightness	1,2,3,4,5,6,7,8,9,10	1 = Lowest Brightness 5 = Medium Brightness 10 = Max Brightness
led_enabled	true, false	Enables/disables the LED
log_events	0 = GPS event 1 = Trigger event 2 = Exposure event	Including the value (0,1,2) means the log event is included in the log. Not including turns it off.
ls_autoexposure	true, false	Light sensor auto exposure (True = Recommended)
ls_integration_time	0-500	The exposure time variable for the light sensor. If auto exposure is true then integration time is not used.
pwm_trigger_autostart	true, false	Autostart image capture on system boot
pwm_trigger_interval	0 - ∞	Number of seconds between Trigger log event. A value of 3 for 3s is recommended for Survey3 RAW+JPG capture mode.

Example Edits to the Configuration File

Adjusting Image Capture Interval

A very common edit to the configuration file is to change the time interval that the images are triggered at. The unit for the interval is seconds, and any number of decimal places are supported For example 3.75, for a 3.75 second interval between image trigger.

"pwm_trigger_interval": 3.75

For the MAPIR Survey3 cameras in RAW+JPG capture mode, the smallest interval we recommend for reliable triggering is a value of 3.0, for 3 seconds between capture. This is the value you would use if you are using the Survey3 camera on an aerial drone performing an autonomous mapping mission.

Automatic Capture at Boot

Perhaps you are controlling the power going to the DAQ and want it to start capturing as soon as it boots up. Then you will want to set the "pwm_trigger_autostart" parameter to true.

Timelapse Mode

For capturing images over a longer time typically you would want to increase the interval time to reduce the number of images captured. Common examples include 60 (capture every 60 seconds / 1 minute), 360 (capture every 360 seconds / 1 hour) and 86400 (capture every 86,400 seconds / 24 hours / 1 day).

If you are controlling the power to the DAQ and you auto-start the capture at boot, you can set an interval to capture any schedule.

Dimming or Turning OFF the Button LED

Most of the time you will probably not need to adjust the LED brightness. For the times you do need to dim the LED or turn it off you just need to edit the "led_brightness" parameter.

"led_brightness": 10

To turn the LED off, edit parameter "led_brightness" to a value of 0.

To dim the LED from the default max of 10 to half the brightness, change the "led_brightness" parameter to 5. To dim it to its lowest, change to a value of 1.

When the image capture sequence is on, the LED will fade between the max brightness set by the "led_brightness" parameter and 1 (most dim). For example, if "led_brightness" is set to 10, it will fade between 10 and 1 (10-1-10-1..).