meshtastic/docs/software/settings/gps.md

id	title	sidebar_label
gps	GPS Settings	GPS

import Tabs from '@theme/Tabs'; import TabItem from '@theme/TabItem';

:::caution Altering/disabling the GPS functionality does not mean that you will be unable to be found. Via triangulation of your radio, location may be given up to someone if they are determined enough. :::

Overview

GPS is provided by either the device or your paired phone. More than likely, you will want to keep GPS functionality operational. It is not required, but does assist in some of the time calculations at a bare minimum.

Settings

Setting	Acceptable Values	Default
fixed_position	true, false	false
gps_attempt_time	integer (seconds)	0 (see note)
gps_operation	GpsOpUnset, GpsOpStationary, GpsOpMobile, GpsOpTimeOnly, GpsOpDisabled	GpsOpUnset
gps_update_interval	integer (seconds)	0 (see note)
location_share	LocUnset, LocEnabled, LocDisabled	LocUnset
position_broadcast_secs	integer (seconds)	0 (see note)
position_broadcast_smart	true, false	false

:::note On gps_attempt_time, gps_update_interval, & position_broadcast_secs when you set these to 0 you are not disabling these features.

On gps_attempt_time and gps_update_interval, the value 0 will be interpreted by the device as the default of 30 seconds. On position_broadcast_secs the value 0 will be interpreted as the default of 15 minutes.

If you wish to disable any GPS features, see below for more information. :::

fixed_position

If set, this node is at a fixed position. The device will generate GPS updates at the regular gps_update_interval, but use whatever the last lat/lon/alt it saved for the node. The lat/lon/alt can be set by an internal GPS or with the help of the mobile device's GPS.

gps_attempt_time

Determines the amount of time that a GPS fix should be allowed to take. The default is every 30 seconds. If you increase this value, it will allow the device that amount of time in seconds to acquire coordinates. If the device is unable to get a fix, it will turn off until the next interval. GPS coordinates are updated every gps_update_interval seconds.

gps_operation

How the GPS hardware in the device is operated.

:::note This is independent of how our location is shared with other devices. For that see location_share. :::

Value	Description
GpsOpUnset	Default: operates the same as GpsOpMobile.
GpsOpStationary	Note: This mode was removed, because it is identical go GpsOpMobile with a gps_update_interval of once per day This node is mostly stationary, we should try to get location only once per day, Once we have that position we should turn the GPS to sleep mode This is the recommended configuration for stationary 'router' nodes
GpsOpMobile	This node is mobile and we should get GPS position at a rate governed by gps_update_interval
GpsOpTimeOnly	We should only use the GPS to get time (no location data should be acquired/stored) Once we have the time we treat gps_update_interval as MAXINT (i.e. sleep forever)
GpsOpDisabled	GPS is always turned off - this mode is not recommended - use GpsOpTimeOnly instead.

gps_update_interval

Determines how often should the device should attempt to acquire a GPS position (in seconds). The length of time the device is allowed to attempt to acquire GPS coordinates each interval is set using gps_attempt_time. The default is every 30 seconds.

location_share

Determines whether location is shared with other nodes. See more details.

Value	Description
LocUnset	Default: operates the same as LocEnabled
LocEnabled	The device is sharing its location (or the paired phone's location)
LocDisabled	The device is not sharing its location (if the unit has a GPS it will default to only get time - i.e. GpsOpTimeOnly)

position_broadcast_secs

How often our position is sent to the mesh (but only if it has changed significantly).

The GPS updates will be sent out every position_broadcast_secs, with either the actual GPS location, or an empty location if no GPS fix was achieved. This defaults to broadcast every 15 minutes.

position_broadcast_smart

position_broadcast_smart will send out your position at an increased frequency only if your location has changed enough for a position update to be useful.

Complements position_broadcast_secs (doesn't override that setting) but will apply an algorithm to more frequently update your mesh network if you are in motion and then throttle it down when you are standing still. If you use this feature, it's best to leave position_broadcast_secs at the default.

position_broadcast_smart will calculate an ideal position update interval based on the data rate of your selected channel configuration.

As an example, if you configure your radio to use Long Range / Fast, if you have traveled at least 144 meters and it's been at least 61 seconds since the last position update, a new position broadcast will be sent out. If you've moved less than 144 meters, we will broadcast the position based on the value of position_broadcast_secs.

The table below is a summary computed values from the algorithm.

Long Name	Update every x-seconds	Update distance traveled (meters)
Long Range / Slow	88	150
Long Range / Fast	61	144
Medium Range / Slow	30	41
Medium Range / Fast	30	30
Short Range / Slow	30	30
Short Range / Fast	30	30

Note: A person walking in a straight line will take about 90 seconds to travel 150 meters. That walking speed estimate was used as the baseline for the formula used.

Examples

Disable GPS Completely

<Tabs groupId="settings" defaultValue="cli" values={[ {label: 'CLI', value: 'cli'}, {label: 'Android', value: 'android'}, ]}>

meshtastic --set gps_operation GpsOpDisabled

TODO

:::note gps_operation GpsOpTimeOnly is preferred to gps_operation GpsOPDisabled because it allows the device to get a hi-res time. :::

Disable Location Sharing

<Tabs groupId="settings" defaultValue="cli" values={[ {label: 'CLI', value: 'cli'}, {label: 'Android', value: 'android'}, ]}>

meshtastic --set location_share LocDisabled

TODO

:::note Disabling location sharing does not disable the GPS functionality, only the location sharing via the mesh. :::

Set Fixed Position – Current Lat/Lon

<Tabs groupId="settings" defaultValue="cli" values={[ {label: 'CLI', value: 'cli'}, {label: 'Android', value: 'android'}, ]}>

meshtastic --set fixed_position true

TODO

:::note The device will continue to acquire GPS coordinates according to the gps_update_interval, but will use the last saved coordinates as its fixed point. :::

Set Fixed Position – Specify Lat/Lon

<Tabs groupId="settings" defaultValue="cli" values={[ {label: 'CLI', value: 'cli'}, {label: 'Android', value: 'android'}, ]}>

meshtastic --setlat 37.8651 --setlon -119.5383

TODO

Unset Fixed Position

<Tabs groupId="settings" defaultValue="cli" values={[ {label: 'CLI', value: 'cli'}, {label: 'Android', value: 'android'}, ]}>

meshtastic --set fixed_position false

TODO

:::note It may take some time to see that the change has taken effect. The GPS location is updated according to the value specified on gps_update_interval and the mesh will be notified of the new position in relation to the position_broadcast_secs value. :::