HONEST NUMBERS

Specifications

Every row is tagged. measured was taken on this board; datasheet is from the part maker; target is a design goal, not a field measurement.

Hardware

Item	Value
MCU	ESP32-S3-WROOM-1, 16 MB flash, 8 MB PSRAM	datasheet
Display	ED047TC1, 4.7″, 960×540, 16 grey levels, parallel bus	datasheet
GNSS	Quectel L76K at 9600 (this unit)	measured 2026-09-28
LoRa	SX1262, 915 MHz, U.FL pad (no SMA on this board)	datasheet
Battery	3.7 V 1500 mAh, MagSafe charging; BQ27220 gauge	datasheet
Touch	GT911	datasheet
Storage	microSD (SPI, 8 MHz kept after CRC-matched upload)	measured 2026-09-30
Missing	No compass, no barometer, not waterproof	datasheet

Operation	Time
Marker window MODE_DU (~84×64 / 80×80 class)	143 ms	measured 2026-09-28
Full-screen MODE_DU	178 ms	measured 2026-09-29
Full-panel MODE_GL16	891 ms	measured 2026-09-28
epd_fullclear	2762 ms	measured 2026-09-28
Warm map render, Bay sheet, zoom 12→16	446 / 391 / 298 / 299 / 257 ms	measured 2026-10-13
20 px marker move (100×80 DU)	145 ms	measured 2026-10-06

Diymore tester, 0.01 A / 0.01 W steps, battery full and charge done, so the reading is board load at 5 V. 2026-10-13.

State	Reading
Awake, GNSS hunting / LIVE / recording	0.46–0.52 W (≈0.09–0.10 A)	measured 2026-10-13
TRACK unlocked (light sleep ~50–60%)	≈0.30 W	measured 2026-10-13
TRACK locked at a weak-signal window	≈0.41 W	measured 2026-10-13
Front light High (added)	+0.35–0.4 W	measured 2026-10-13
LoRa RX / idle Wi-Fi	Below 0.01 A step	measured 2026-10-13
Deep sleep	Below tester resolution	measured 2026-10-13

State	Reading
Deep sleep	0.6–0.9 mA	measured 2026-10-13
Recorded walk, Auto, LoRa/light off (1 h 50 min, 1499→1354 mAh)	≈79 mA average → ~19 h continuous recording on the stock cell	measured 2026-10-13
Locked TRACK after Finish	≈48 mA	measured 2026-10-13
Multi-day TRACK with external power bank	~5 days	target
STATIC deep sleep, weeks on the stock cell	Weeks	target

The gauge may undercount small currents. A full battery-side table for every GPS mode is still open. Ledger: docs/power.md in the firmware repo.

Item	Value
Indoor hot fix after UART open	1.4 s to q=1 (7–8 sats used)	measured 2026-09-28
Cold-start TTFF outdoors	Not measured yet	open
L76K tracking current	18–29 mA	datasheet
Periodic NMEA after power-up	Must send $PCAS03; not assumed on	measured 2026-09-28

Item	Value
Sheet size	0.5° grid (~55 km N–S), typically 4–16 MB	measured
Device zooms	12–16 (native tiles at 12/14/16)	measured
Contours / DEM	20 m contours; 64×64 DEM blocks for profiles	measured
Wi-Fi upload (pipelined, 8 MHz SD)	331 KiB/s avg for a 6.6 MB sheet	measured 2026-09-30

Item	Value
Protocol	Meshtastic US LongFast	measured 2026-10-19
TX power (first field use)	2 dBm	measured 2026-10-01
Antenna	U.FL pad; no SMA on this store variant	datasheet
Default	Off	product