Configuration

AstroNav Nano stores its main user configuration in Settings.ini.

Settings.ini

Connect through USB

Before connecting the board:

1. Disconnect the battery, E-match, pyro charge, and other hazardous hardware.
2. Connect the AstroNav Nano to the programming board with the flat cable.
3. Connect the programming board to your computer with a USB-C data cable.
4. Wait for the board startup checks to finish.
5. Open the AstroNav Nano USB drive in File Explorer.

The drive should contain:

• Howto.txt
• Settings.ini

Open Settings.ini from the root of the AstroNav Nano drive:

Settings.ini

Normal configuration values are stored under:

[settings]

Configuration scope

Only edit values in this section unless you specifically know why another section needs to be inspected.

Available settings

Setting	Description	Default
ESTIMATED_HEIGHT_M	Expected apogee height in metres	120.0
HEIGHT_MARGIN_M	Allowed height tolerance around the estimate	20.0
ESTIMATED_SPEED_MPS	Expected climb speed in metres per second	35.0
SPEED_MARGIN_MPS	Allowed speed tolerance around the estimate	8.0
LAUNCH_THRESHOLD_G	Acceleration threshold used for launch detection	1.35
FIRE_PYRO_APOGEE	Enables or disables automatic apogee pyro output	TRUE
MIN_PYRO_FIRE_HEIGHT_M	Minimum climb above the launch point before the pyro may fire, in metres. Dangerous setting, see below. Firmware v1.2.2 and later.	5.0

Recommended configuration workflow

For a new board:

1. Start with the default values.
2. Change only settings you understand.
3. Save Settings.ini.
4. Eject the drive: select Eject in the top bar of AstroNav MC, or in Windows File Explorer right-click the AstroNav Nano drive and select Eject.
5. Wait for the device to leave USB storage mode, then reconnect it if you need to check the file again.
6. Open Settings.ini again.
7. Confirm that your settings were saved.

FIRE_PYRO_APOGEE

Automatic apogee deployment

To allow automatic apogee deployment:

FIRE_PYRO_APOGEE=TRUE

Detection-only testing

To detect and log apogee without automatically activating the pyro output:

FIRE_PYRO_APOGEE=FALSE

This is useful for detection and sensor testing.

Physical disconnection

Disabling automatic firing in software is not a replacement for physically disconnecting hazardous hardware.

MIN_PYRO_FIRE_HEIGHT_M

The pyro never fires unless the rocket climbed at least this many metres above the launch point. The default is 5.0; the allowed range is 0 to 10000.

MIN_PYRO_FIRE_HEIGHT_M=5.0

This protects people handling an armed board. If a bump while carrying the rocket is mistaken for a launch, the pyro still cannot fire close to the ground. When the pyro is blocked by this setting, the flight log shows PYRO_BLOCKED_REASON=below_min_height.

Dangerous setting

MIN_PYRO_FIRE_HEIGHT_M=0 disables this protection. Only lower the value if you fully understand the consequence. Independently of this setting, the pyro never fires when the barometer is unreliable.

Firmware older than v1.2.2 does not have this setting. AstroNav MC then hides the field.

Other sections

[debug]

Contains diagnostic information generated by the firmware.

Generated diagnostics

Do not normally edit this section.

[checks]

Contains health-check information generated by the firmware.

Do not normally edit this section.

[profile]

Contains device identity and stored flight information.

AstroNav MC

AstroNav MC provides a graphical interface for working with AstroNav Nano.

It can be used for:

• Editing settings
• Reading flight logs
• Viewing flight summaries
• Simulating mission behavior
• Validating configurations

AstroNav MC complements the onboard firmware.

It does not replace onboard safety logic or physical flight-readiness checks.