The device has no magnetometer (issue #16): north is given by the course
over ground while walking, or by aiming at the sun, and the gyroscope
follows the turn around the vertical in between. With the sun's position
from the time and the place, the bearing to a point, the 16 points and
distances as text. Host-tested.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0162FokPdvY2KsS4NBfwyWPk
Settings had grown to 21 rows in one list. It opens on five groups (This
device, Display, GNSS and radio, Network, System); Enter opens one, Back
returns to the groups, and Back from the groups leaves Settings.
SettingsMenu holds the groups and which one is open (host-tested: every
setting is in exactly one group). The guide, the how-tos, the README,
the scripts' messages and the firmware's own name the new paths, such as
"Settings > System > Firmware".
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0162FokPdvY2KsS4NBfwyWPk
`r` in the GNSS App (or `gnss track start|stop`) records a Track to
/gnss/tracks/YYYYMMDD-HHMMSS.gpx: a point every 5 s once moved 5 m
(lib/gnss/track, 7 tests: haversine, the rule, GPX text, the file name).
It keeps recording with the App closed, shows REC in the Status Bar, and
announces start and stop with a Toast. It needs a card and the time;
switching GNSS off stops it. Tracks are written like Captures: past 90 %
card usage, until full. Storage Clean-up gets a GNSS tracks category.
A Track cut short by a reset or power loss has no GPX footer; the GNSS
Service closes such files at the next boot.
Verified on the device: a recorded Track and one interrupted by a reset
both parse as GPX 1.1 on the PC.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT
Position: the Fix line (or how long it has been searching), latitude and
longitude in decimal degrees or degrees-minutes-seconds (Settings ->
Coordinates), the Maidenhead locator, altitude, speed and course, HDOP
and UTC. Sky: the satellites by azimuth and elevation, coloured by
constellation, filled when used in the Fix, with used/in-view counts.
Tab switches. lib/gnss/geo_format holds the formatting, the locator and
the sky projection, host-tested (6 tests; locators checked against
FN31pr and JN58td).
Verified on the device by a window: 3D Fix from GPS, GLONASS, Galileo
and BeiDou.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT
The GNSS Service reads the receiver (UART 15/13, 115200, 1 KB buffer)
from its 50 ms tick and feeds the NMEA parser. With a Fix it sets the
clock (GNSS is the most trusted TimeSource) and refreshes it every 10
min. Settings gets GNSS On/Off and the coordinate format (Q64).
Off puts the receiver in standby with $PCAS12,65535, renewed hourly; On
wakes it with a hot start, $PCAS10,0. Both measured on the device: the
output stops within a second, and a command wakes it within a second.
Commands: gnss status (Fix, satellites per constellation, bytes and
sentences), gnss nmea on|off, gnss send <sentence>, gnss restart. The
probe is gone; never drive GPIO 15 (the receiver's output): the first
probe's swapped-pin attempt silenced it until a power cycle.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT
lib/gnss: RMC, GGA, GSA and GSV into one GnssState: Fix type, position,
altitude, speed, course, HDOP, UTC time (trusted only with a Fix) and the
satellites in view across constellations. GSV sequences are kept per
constellation and signal band and merged per satellite with the stronger
SNR; GSA's system ID marks which satellites are used. 16 tests, using
lines captured from the device.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT
twislaandClaude Opus 5.5