Microphone on I2S_NUM_0 (PDM hardware constraint), speaker moved to
I2S_NUM_1. Both init at boot, shut down before deep sleep.
Mic provides raw audio read and RMS level measurement.
Boot beep disabled (speaker confirmed working).
I2S audio output on GPIO 9/10/11 (BCLK/WCLK/DOUT). Sine wave tone
generator with predefined alert sounds: beep, alert, success, error.
Boot beep confirms speaker is working. Speaker shut down before deep
sleep to release I2S driver.
Touch driver via SensorLib TouchDrvCST92xx on I2C 0x1A with interrupt
on GPIO 12. Touch events unblank the display and reset the blanking
timer. Display blanks after 10 seconds of inactivity.
XL9555 TOUCH_RST now explicitly released at boot. Touch init runs
with explicit I2C_SDA/I2C_SCL pins (same fix as XPowersLib).
BHI260AP firmware upload (~260KB at 1MHz I2C) takes ~10 seconds and
blocks the main loop. Moved init from setup() to a deferred check in
the main loop that runs once after 5 seconds when hw_ready is true.
This allows the radio and serial to come up immediately while the
sensor firmware uploads in the background.
Also restores XL9555 DRV_EN and DISP_EN enables at boot (lost during
earlier git checkout/stash operations).
Minimal I2C driver for the DRV2605 ERM vibration motor. 117 built-in
effects via the ERM effect library. Named constants for watch use
cases (click, bump, alert, buzz, tick, etc.).
Boot: sharp click on startup. Sleep: soft bump before entering deep
sleep. XL9555 DRV_EN and DISP_EN now explicitly enabled at boot.
Updated Makefile upload-twatch_ultra to set firmware hash after JTAG flash.
Three critical fixes:
- Remove PMU->enableSleep() which bricked AXP2101 I2C across resets
- Remove I2C pins (GPIO 2/3) from OPEN_DRAIN list — gpio_reset_pin()
already sets INPUT mode, and OPEN_DRAIN persists in battery-backed
RTC domain, corrupting the I2C bus
- Use esp_reset_reason() == ESP_RST_DEEPSLEEP for reliable cold boot
vs timer wake discrimination
Extracted twatch_enter_deep_sleep() shared helper used by both
sleep_now() and beacon_wake_cycle(). Adds co5300_sleep() call
before SPI.end() to properly shut down display controller.
Tested: sleep via long-press, wake via button, radio reconnects,
display re-initialises, I2C bus intact across multiple cycles.
Root cause: XPowersAXP2101(Wire) constructor defaults to SDA=8, SCL=9
(from generic esp32s3 variant pins_arduino.h). Its begin() method then
calls Wire.begin(8, 9), overriding our Wire.begin(3, 2). All I2C
traffic went to the wrong GPIO pins.
Fix: pass explicit I2C_SDA, I2C_SCL to the XPowersAXP2101 constructor
so it uses GPIO 3/2 (the T-Watch Ultra's actual I2C pins).
Also removed I2C diagnostic/recovery code that was debugging the
wrong problem.
Three photos from disassembly session:
- PCB overview with back cover removed
- PCB closeup showing component labels
- Battery connector detail
Factory firmware reflashed to verify hardware integrity. I2C bus and
display confirmed working under LilyGo firmware. RNode firmware I2C
init needs debugging — Wire.begin succeeds but no slaves respond.
Key finding: deep sleep GPIO OPEN_DRAIN configuration persists in the
battery-backed RTC domain, corrupting the I2C bus across reboots.
Wire.begin() returns false after deep sleep has been entered once.
I2C bus recovery attempt added (SCL clock-out + STOP condition) but
Wire (I2C0) peripheral remains stuck. Wire1 (I2C1) works on same pins
but no slave devices respond — bus lines may be held by stuck slaves.
Found from schematic: XL9555 DOES control VC_EN (display VCI power).
Display QSPI pins confirmed correct from schematic (sheet 4).
BHI260AP SensorLib removed (was causing boot failure due to firmware blob size).
Beacon wake cycle still disabled pending I2C fix.
Critical TODO: fix deep sleep to not set I2C pins to OPEN_DRAIN,
or add robust I2C bus recovery in early boot before PMU init.
Added SensorLib dependency (v0.3.1) with BHI260AP GPIO firmware
for controlling display power gate, haptic driver, and touch reset
via the sensor's auxiliary GPIO pins.
Fixed beacon wake cycle triggering on cold boot — disabled pending
proper deep sleep vs cold boot discrimination.
Display status: BHI260AP begin() returns false (firmware upload
failing). CO5300 QSPI driver still cannot reach display controller.
Both issues under investigation.
Standalone GPS beacon mode: when no KISS host is connected for 15s,
the RNode transmits position and battery telemetry over LoRa.
Two beacon paths:
- LXMF (recommended): encrypted per-packet messages with announces,
compatible with Sideband and any LXMF application. Supports IFAC
network authentication.
- Legacy JSON: plaintext or encrypted raw packets for simple collectors.
Key changes:
- GPS support for T-Beam Supreme S3 (L76K) and Heltec V4 (external)
- SX1262 radio fixes: IQ polarity, DCD preamble lockup, RX reliability
- LXMF identity management with NVS-backed Ed25519/X25519 keys
- IFAC authentication (CMD_IFAC_KEY 0x89) for private networks
- Per-channel serial isolation (USB, BLE, WiFi)
- GPS status page in OLED display rotation
- Provisioning via rnlog: provision-lxmf, provision-ifac
- Documentation in Documentation/BEACON.md
