94 lines
2.9 KiB
Markdown
94 lines
2.9 KiB
Markdown
# DD3 LoRa Bridge Raspi Debugger
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Headless Raspberry Pi Zero W project:
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- WiFi client or fallback AP (`serial` / `serialserial`)
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- Web portal (`http://192.168.4.1/` in AP mode)
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- ESP32 USB serial bridge with live SSE stream and daily log files (`/home/pi/xxx_YYYY-MM-DD_HH-MM-SS.log`)
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- Stable symlink to active log (`/home/pi/xxx.log`)
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- RTC boot restore + NTP sync + RTC write-back
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- Autostart via systemd
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## Current State
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Current implementation status:
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- Boot flow restores system time from RTC (`hwclock -s`) before starting services.
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- RTC device auto-detection checks: configured device, `/dev/rtc`, `/dev/rtc0`, `/dev/rtc1`.
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- If WLAN is disconnected for ~60s, AP fallback starts on `wlan0`:
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- SSID: `serial`
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- Password: `serialserial`
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- AP IP: `192.168.4.1/24`
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- DHCP range: `192.168.4.10` to `192.168.4.200`
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- Web portal is available on port `80`:
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- `/` WiFi scan + connect UI + system actions (reboot/shutdown)
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- `/serial` live serial console (SSE via `/events/serial`)
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- `/api/status` polling is reduced/throttled (15s) for Pi Zero W performance
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- ESP32 serial bridge:
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- Auto-detects `/dev/ttyUSB*`, `/dev/ttyACM*`, `/dev/serial/by-id/*`
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- Reconnects automatically on unplug/replug
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- Daily log rollover at midnight with datetime filename
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- No log file is created while no serial device is connected
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- Once internet is available, NTP sync runs and writes corrected time back to RTC (`hwclock -w`).
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- After boot is ready, power/activity LED is set to 1 Hz blink (`timer`, 500ms on / 500ms off), if LED sysfs control is available.
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Note:
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- Reboot/shutdown actions in the web UI currently have no authentication. Restrict access to trusted networks only.
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Runtime check commands:
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```bash
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systemctl status serial-bridge
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journalctl -u serial-bridge -f
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ip a show wlan0
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ls -l /home/pi/xxx.log /home/pi/xxx_*.log
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sudo hwclock -r
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```
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## RTC GPIO Wiring (Raspberry Pi Zero W)
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Use I2C1 pins on the 40-pin header:
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| RTC module pin | Raspberry Pi pin | BCM GPIO | Notes |
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|---|---|---|---|
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| `VCC` | `Pin 1` | 3V3 | Use 3.3V |
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| `GND` | `Pin 6` | GND | Common ground |
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| `SDA` | `Pin 3` | GPIO2 (`SDA1`) | I2C data |
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| `SCL` | `Pin 5` | GPIO3 (`SCL1`) | I2C clock |
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Minimal pin marker (header top):
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```text
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Pin 1 (3V3) Pin 2 (5V)
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Pin 3 (SDA1) Pin 4 (5V)
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Pin 5 (SCL1) Pin 6 (GND)
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```
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Enable I2C + RTC overlay (example DS3231):
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```bash
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sudo raspi-config nonint do_i2c 0
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echo 'dtoverlay=i2c-rtc,ds3231' | sudo tee -a /boot/firmware/config.txt
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sudo reboot
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```
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Verify:
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```bash
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ls -l /dev/rtc*
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sudo i2cdetect -y 1
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sudo hwclock -r
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```
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## Quick install (on Raspberry Pi)
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```bash
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chmod +x install.sh
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sudo ./install.sh
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```
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Installer behavior:
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- First run: full install (apt packages, venv, pip deps, configs, services).
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- Re-run/update: fast path, skips apt and pip when not needed.
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- `pip install` runs only when `requirements.txt` hash changed (or venv missing).
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Optional reboot after first install or low-level config changes:
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```bash
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sudo reboot
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```
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