Upgrade ArduinoHA from 1.3.0 to 2.1.0 and rewrite mqtt.ino for it. The clock now shows up in Home Assistant (discovery prefix "homeassistant") with: - switches Tubes (blank the display, runtime only) and Auto dim - numbers Day/Night brightness - light Backlight (on/off, brightness, RGB mapped to the colour wheel) - select LED effect, button Cathode protect - sensors Light (LDR) and WiFi signal, plus the upstream sensors when the clock has them; master-clock subscriptions are kept Settings changed from HA are saved to EEPROM 3 s after the last change. Fixes the unbounded memcpy in the MQTT message handler. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
98 lines
5.8 KiB
Markdown
98 lines
5.8 KiB
Markdown
# Nixie clock: notes for Claude
|
|
|
|
An AliExpress WiFi nixie clock (4x IN-12 + 2x IN-3 neon dots, 8x WS2812) that is being
|
|
moved from its closed stock firmware to ESP_UniClock (https://github.com/gpeter62/ESP_UniClock)
|
|
with ArduinoOTA and Home Assistant (MQTT) support.
|
|
|
|
## The device
|
|
|
|
- On the network at **10.1.1.97** (WiFi `dlink-iot`). Since 2026-10-25 it runs ESP_UniClock
|
|
(`firmware/uniclock/`, CLOCK_90): web UI on port 80 (JSON at `/getConfiguration`,
|
|
`/getCurrentInfos`), ArduinoOTA on UDP 8266 (hostname `nixie-in12`, no password yet).
|
|
- Board: RetroModding (Konstantin Repnikov) "NixieIN12v2 HV2.0", stock firmware **SV1.3**
|
|
(©2020). ESP-12 (ESP8266, MAC 30:83:98:99:BF:DE, Espressif).
|
|
- **Powered by USB-C 5 V only** (no DC jack). Most likely the maker's "v2.0L lightweight
|
|
5 volt version". The user says the PCB looks different from the 12 V v2 board.
|
|
- **No buttons fitted**, only the light sensor.
|
|
- Stock settings (2026-10-25): time zone +01:00, EU DST on, NTP `time.euro.apple.com`,
|
|
brightness auto, 24 h. Stock DST might not work: check in late March.
|
|
|
|
## Stock firmware (from the flash dump)
|
|
|
|
- `firmware/stock/nixie_stock_SV1.3_full_4MB.bin` (gitignored), SHA-256
|
|
`b069f4eb93cf1e9063a30374db4d70508211f07b0a17049bcf9ebdeda65f2985`, verified against the chip
|
|
with `verify-flash`. Flash: 4 MB, DIO, 40 MHz.
|
|
- Arduino ESP8266 core 2.x (NONOS SDK 2.2.2-dev), built for board `ESP8266_NODEMCU`. App
|
|
at 0x1000 (~1 MB slot), SPIFFS at 0x200000. Settings live in SPIFFS as JSON
|
|
(`/config.json`, `/wifi.json`, `/light.json`, `/leds.json`, `/alerts.json`, `/hardware.json`).
|
|
- **Hidden pages**: `/d` = "Hardware setting" (hidden from the menu by default). It has
|
|
checkboxes to hide/show menu items and a **Debug mode** (`dev`) checkbox. With Debug
|
|
mode on, `/u` serves the standard ESP8266HTTPUpdateServer upload form, which is web OTA
|
|
for `.bin`/`.bin.gz`. `/r` reboots on a plain GET; don't GET unknown paths blindly.
|
|
- No pin numbers are visible as strings; confirming the pinout needs disassembly or the
|
|
bit-stepping test sketch.
|
|
|
|
## Pinout
|
|
|
|
From the 12 V v2 schematic (`docs/schematic_v2_12V.jpg`), checked against the stock firmware
|
|
by disassembly (`docs/stock-firmware-pins.md`, tools in `tools/`). "Hardware" = also works
|
|
on the clock with UniClock; "Binary" = only confirmed in the stock SV1.3 code.
|
|
|
|
| Function | GPIO | Source |
|
|
|---|---|---|
|
|
| 74HC595 DATA / CLOCK (OE tied to GND) | 13 / 14 = HSPI MOSI / SCK (hardware SPI, MSB first) | Hardware |
|
|
| 74HC595 LATCH | 15, plain `digitalWrite` (has 1k pull-down) | Hardware |
|
|
| WS2812 data | 12 (NeoPixel bit-bang, GRB 800 kHz; 8 fitted, stock assumes 12). `SPI.begin()` turns GPIO12 into MISO: set it back to OUTPUT afterwards | Hardware |
|
|
| Photoresistor (LDR, 10k to GND) | ADC (A0) | Hardware |
|
|
| BTN1 / BTN2 (not fitted) | 0 / 2, INPUT_PULLUP. Stock: GPIO0 is a button, GPIO2 a motion/presence input that wakes the display | Binary |
|
|
| DFPlayer Mini (stock feature) | UART0: GPIO1 TX / GPIO3 RX, 9600 Bd | Binary |
|
|
| DS3231M RTC SDA / SCL | 4 / 5: **no I2C device answers** (UniClock scan), so no RTC on this board; NTP only | Hardware |
|
|
|
|
Two chained 74HC595s make one 16-bit word, all bits active-high (confirmed from the binary;
|
|
the high byte is sent first and goes to U2):
|
|
- U1 QA..QH = cathodes 0..7 (bits 0..7), U2 QA = cathode 8 (bit 8), QB = cathode 9 (bit 9)
|
|
(via 2x ULN2003, shared by all tubes)
|
|
- U2 QC = P1 (bit 10) drives **both** IN-3 neon dots. QD..QG = anodes A1..A4 (bits 11..14,
|
|
MMBTA42/92). QH = P2 (bit 15) drives the IN-12B **decimal points** on this board (JP2 closed),
|
|
not a neon.
|
|
- The display is multiplexed: one anode on at a time. **A1 = leftmost tube (hour tens),
|
|
A4 = rightmost (minute ones)** (verified on the tubes). The dots are lit in the minute-tens
|
|
slot only, as on stock.
|
|
|
|
## Programming header
|
|
|
|
Header on the PCB: GND, GPIO0, RST, RXD, TXD, 3.3V. The USB-C port only supplies power.
|
|
Flashing is done with a CH340C board on **COM7** (COM3 is another device; leave it alone).
|
|
Wiring: GND-GND, adapter TXD -> clock RXD, adapter RXD -> clock TXD, adapter 3.3V not
|
|
connected (the clock is powered from its own USB-C). No auto-reset: to enter flash mode, hold
|
|
GPIO0 to GND, tap RST to GND, then release GPIO0.
|
|
|
|
- esptool is installed for the user (`python -m esptool`, v5.6.0). After `--after no-reset`
|
|
the stub keeps running at the new baud rate and the next esptool call can't connect: do
|
|
everything in one call, or re-enter flash mode.
|
|
- Normal updates go over WiFi: `pio run -e nixie_in12_ota -t upload` in `firmware/uniclock/`.
|
|
ArduinoOTA does not answer after the clock switched from AP mode to WiFi without a reboot
|
|
(first setup); a power cycle fixes it.
|
|
- `firmware/stock/` holds the stock flash dump. **Never overwrite or delete it**; it is the
|
|
only way back to SV1.3 (`write-flash 0 <dump>`). Dumps are gitignored because the flash
|
|
holds the WiFi password; never commit them.
|
|
|
|
## Constraints
|
|
|
|
- The 170 V tube supply is live whenever USB-C is connected.
|
|
- Hardware is only reachable via the user: anything that needs RST/GPIO0 or looking at the
|
|
tubes must be asked of them. Builds can be checked here, but runtime behaviour can't.
|
|
- Show the exact plan before making changes to the device (flashing, saving settings).
|
|
|
|
## Plan
|
|
|
|
1. Done: dump and inspect the stock firmware.
|
|
2. Skipped (the disassembly was enough): bit-stepping test sketch.
|
|
3. Done: 74HC595-multiplex driver (`nixie595.ino`) + CLOCK_90 in ESP_UniClock, ArduinoOTA,
|
|
EU DST fix. Runs on the clock.
|
|
4. Done: Home Assistant over MQTT (broker 10.1.1.175, discovery prefix `homeassistant`).
|
|
`mqtt.ino` rewritten for ArduinoHA 2.1.0: switches Tubes/Auto dim, numbers Day/Night
|
|
brightness, light Backlight (on/off, brightness, RGB -> UniClock colour wheel), select LED
|
|
effect, button Cathode protect, sensors Light/WiFi signal. Broker settings are read at boot.
|
|
5. Open: OTA password via `secrets.h`; ArduinoOTA after the AP -> WiFi switch.
|