twislaandClaude Opus 5.5
544bd726df
Tab goes on from the Sky to a third view (issue #16): a rose that turns with the device, the heading, where north came from and how long ago, the sun on the rose, and a level. m marks where you stand as a Place, t picks one as the target: an arrowhead on the rose, its distance and bearing. The sensor's directions were checked by hand on the device. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_0162FokPdvY2KsS4NBfwyWPk
4.2 KiB
+++ title = "GNSS" description = "Where you are, which satellites you can see, and a compass that leads back to a place you marked, from the Cap's receiver, with Tracks saved to the SD card as GPX." weight = 3 [extra] tag = "GNSS" screens = ["sky.png"] +++
GNSS needs the Cap LoRa-1262, an antenna with a view of the sky, and Settings → GNSS and radio → GNSS switched On. Otherwise the App says GNSS is off (or paused, when "Pause GNSS for LoRa" has put the receiver on standby while the radio listens). A first fix outdoors can take a while: the App says how long it has been searching.
Position
The first view shows the fix (No Fix, 2D Fix or 3D Fix, and how many satellites it uses), then:
- Lat and Lon, in decimal degrees or degrees, minutes and seconds (Settings → GNSS and radio → Coordinates);
- the Locator, the Maidenhead grid square;
- Altitude, Speed and the direction you are moving;
- HDOP, the horizontal precision: a smaller number is better;
- the Time, in UTC.
Once there is a fix, the device's clock follows it.
Sky
Tab goes from Position to Sky: a circle with N, E, S and W, where each satellite is a dot, coloured by constellation, and filled when the receiver uses it. A legend counts, for each constellation (GPS, GLONASS, Galileo, BeiDou), the satellites used and in view.
Compass
Tab once more shows the Compass: a rose that turns with the device, so that its red N and the bright half of its needle stay to the north. The mark at the top of the rose is the top of the device, and the number beside it is where that points, in degrees and as one of 16 points (247° WSW).
The device has no magnetometer, so it cannot find north by itself. It learns it in one of two ways, then follows your turns with its motion sensor:
- Walk. At a walking pace (3 km/h or more) the receiver knows which way you are going, and the Compass takes that as where the device points. Hold it pointing ahead of you.
- Aim at the sun. Hold the device flat, point its top edge at the sun, and press s: the Compass works out where the sun is from the time and your position. It needs a fix, and the sun above the horizon.
Until one of these has happened the rose is dim and the screen says North is not known. After that, the line under the heading says where north came from and how long ago (the sun, 40 s ago). The motion sensor drifts by a few degrees a minute, so north should be given again now and then: after three minutes the line changes colour. Laying the device down for a few seconds lets the sensor steady itself and drift less. Leaving the GNSS App forgets north.
A yellow dot on the rose is the sun, where it is now: if the dot is not towards the sun, north is off.
The circle at the bottom is a level: its bubble is in the middle, and green, when the device is flat.
Places
m marks where you are standing as a Place, under a name you type (the car, the tent), and makes it the target. With a target, the rose carries a cyan arrowhead that points to it, and the screen shows its name, how far it is and its bearing (340 m 285°): turn until the arrowhead is at the top and walk.
t lists the Places with their distances, to pick another target, or none; d in that list removes one. The Places are kept on the SD card in /gnss/places.gpx, as GPX waypoints: a map program opens the file, and waypoints you put in it from one show up in the list (50 at most).
Tracks
r starts recording a Track: the route is saved as a GPX file on the SD card, in /gnss/tracks (named by date and time), and the Status Bar shows REC. Press r again to stop. A Track keeps recording with the App closed. It needs a card and a clock (a fix or Wi-Fi sets it); if it cannot start, the App says why: GNSS is off, No SD card or Waiting for the time. The Storage App opens a .gpx file and shows its points, start, duration and distance.
The keys, as the device lists them
What Fn + h shows on these screens. These tables are generated from the firmware's own lists, so they are always the current ones.
{{ keys(scopes=["gnss", "gnss-compass", "gnss-places"]) }}