Two answers to "does the compass app matter for battery life", both yes-ish
and both now fixed.
The driver put the QMC6309 into normal mode at boot and left it there, so it
converted continuously from power-on whether or not anything read it: ~1 mA at
100 Hz / OSR 8, forever, on a 2300 mAh battery. It is now parked in suspend
after configuration and woken on demand, with m9CompassIdleTick() (called from
the M9's existing per-loop branch) suspending it again two seconds after the
last read. Waking is a single register write since suspend preserves the
configuration; the waking call reports "nothing fresh" and the caller's next
poll gets data, which callers already handle because the chip may be absent.
Separately, lv_timer_handler() runs unconditionally, so a Lua app's timer kept
firing while the display slept -- GPS Compass polled the magnetometer at 10 Hz
into a dark screen, which would have held the sensor awake even after the fix
above. The host now skips the tick while the screen is off and resumes on wake;
dt comes from millis(), so an app sees one long frame rather than a broken
clock. Documented on the SDK page.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The sensor's orientation on the board is documented nowhere, so it was
measured: held flat, logging the raw vector at four headings 90 deg apart
(M9_COMPASS_DEBUG, now off again) gives a hard-iron centre of
(-0.340, -3.378) and, after subtracting it,
N x'=-0.055 y'=+0.310 E x'=+0.268 y'=-0.018
S x'=+0.013 y'=-0.275 W x'=-0.225 y'=-0.016
so atan2(x, y) reads 350/94/177/266 at N/E/S/W -- 0/90/180/270 within a few
degrees, counting up clockwise. +Y is the device's top edge, +X its left.
That is now the default: correct after calibration alone.
This also explains the reversal reported on hardware. The auto-handedness
rule assumed a Z-out-of-screen sensor was the un-mirrored case; it is the
other way round -- held flat north of the magnetic equator, a Z-INTO-screen
sensor reads the downward field as POSITIVE z. Fixed, and the stored
orientation is versioned so values saved against the old formula are
discarded rather than pushing a correct default back off north.
The bias is real and large: ~-3.4 G on Y against a ~0.27 G horizontal
signal, which is why an uncalibrated device barely moves the dial, and why
the range is +/-32 G rather than +/-8 G. Meshtastic's implausible hardcoded
extrema were right after all.
Also: the satellite meter now sits beside the count instead of at the column
edge, and UITask::loop's coarse "ui:gps" stall bucket is split into
timers/threads/input/diag so a 450 ms hitch can be attributed.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
On the ThinkNode M9 every Lua app opened on a white page: the app body is a
clickable object (touch boards need its press events) on the top layer, so
navCollect harvested it as a leaf focus target and navFocusCb's reverse-video
fill painted it solid under the app's widgets -- the canvas on top stayed
dark, which is what gave it away. NAV_SKIP_FLAG would also hide an app's own
buttons from the d-pad, so this adds NAV_PASSTHRU_FLAG (AppPage.h, shared by
both TUs): clickable, never a target itself, children still collected.
M9 compass: low-pass depth 8 at 50 Hz (the datasheet's 0x61 example) read as
sluggish on the dial; now depth 4 at 100 Hz (CTRL1 0x41, CTRL2 0x30). The
app ticks at 100 ms with lighter smoothing to match.
GPS Compass app rebuilt in the RF Monitor's look: a dial with rings,
10/30/90-degree graduations, red north, a lubber mark and the heading in
the centre; a key/value panel (FIX/LAT/LON/ALT/SPD/TGT) with a 10-cell
satellite meter; compact strings where the column is narrow at large fonts.
Confirmed on the M9 by Chris: the dial turns and calibration holds
(gpscompass.sav persists across reboots).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Firmware
- variants/thinknode_m9/M9Compass.{h,cpp}: QMC6309 at 0x7C on the peripheral
bus. Probe by chip id, soft reset with the explicit clear, CTRL2 0x20
(50 Hz, +/-32 G, set/reset on), CTRL1 0x61 (normal, OSR 8/8), read-back
verified. Synchronous read from the Lua host bridge, 1 s cache, lazy
re-probe while the rail-powered part is still in POR, OVFL kept + flagged +
logged. HAS_M9_COMPASS=1 in the env -> new hardware gate CAP_COMPASS.
- src/helpers/WadaNmeaLocationProvider.h: Wadamesh-owned copy of the core
MicroNMEALocationProvider that also exposes RMC speed/course (the core
keeps its parser private; no libdeps patch). M9 target.cpp builds on it,
HAS_GPS_MOTION=1, wadaGpsMotion() for UITask.
- wada.sys.gps(): + alt (m), + speed_kmh/course where the board provides
them (course only while moving -- an empty RMC course parses as 0), and
nil while the user has GPS switched off. wada.sys.compass(): {x,y,z,ovfl}
Gauss, sensor frame, uncalibrated, registered only where CAP_COMPASS;
caps().compass. Calibration, axis mapping and the heading maths live in
the app so they can be adjusted per user without a firmware cut.
- Host: luaHostContactAt reads the RTC once per contacts() walk instead of
once per contact (an I2C transaction each on the M9); pressCb reports
press coordinates in body content space (scroll offset folded in).
App
- deploy/apps/gpscompass/1.0 + apps.json: rotating rose with a fixed index,
live fix readout, bearing/range to a selected contact, magnetometer
heading with hard-iron calibration (C), frame rotate/mirror (O/F, the
M9's sensor orientation is undocumented), GPS-course fallback on every
other board, saturation warning. Not baked into lua_builtin.h on purpose
(CAP_BUILTIN_LUA_APPS also removes the Store > Apps tab).
Verified: M9, V4, V4-R8, T-Deck compile (M9 flash +2 KB); two adversarial
review passes, all confirmed findings fixed; host Lua harness (vendored
Lua, LUA_32BITS) -- calibration recovers a simulated bias exactly, heading
error 0 deg, worst tick ~10k of the 100k budget. Hardware validation list
(axis orientation, bias magnitude, 0x7C ACK) in M9_PORT.md.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
