thisisnttheway / nixie_clock

ESP32 based nixie clock with IN-14 tubes.

Overview

Nixie clock using IN-14 tubes, based on an ESP32 and programmed with the arduino framework.
Employs FreeRTOS for multitasking.

This project aims to implement the following basic features:

• Acquire time using NTP.
• Store time on external RTC.
• Display time (duh).
• WebGUI for configuring all of the above.

⚠️ Safety warning
These tubes use high voltage (140V+) in operation.
Proper handling and grounding of HV components is critical for personal safety.

Software libraries

This project uses the following libraries:

• ESPAsyncWebServer
  
• AsyncTCP
  
• LittleFS
  
• ArduinoJson
  

Hardware

Microcontroller: ESP32
Indicator tubes: 4x IN-14, 1x IN-3
Opto-isolator: 1x TLP 627-4
Shift register: 2x SN74HC595N (SIPO)
Driver IC: 4x K155ID1

Theoretically, any cylindrical 13 pin IN tube could be used.
However, the PCB will be designed with the dimensions of the IN-14.

Power

The circuit has an intake of 5VDC, which is used for the following purposes:

• Step-up to 170VDC to power all nixie tubes.
• Step-down to 3.3VDC to power all ICs.
  • Exception for the K155D1s as they are not CMOS-based.

ℹ️ The step-up circuit for the 170VDC is not included in the schematic.

Progress

Software-wise, the following features have been implemented so far:

• Implement webserver.
• Implement RTC.
• Implement config files.
• Implement HUE API.
  • Removed as of commit dbf017c67a21eaf4032c0a3266b7488ecc361137
• Change configs from webGUI.
• Implement proper manual time control.
• Implement nixie logic.
  • Test said implementation.
• Implement nixie config in webGUI.
• Store SSID and PSK in config files.
• Change WiFi settings from webGUI.
• Change network settings from webGUI.

Notes

A major code rewrite was conducted on 02.08.2021 that has completely overhauled the base system.
The system runs much more stable now and the codebase has become easier to maintain.

nixie_clock's Issues

Multiple definitions

After initially implementing classes, the compiler fails during the linking process due to multiple definitions:

Currently, #includes are nested like this:

main.cpp
	tasks.h
		nixie.h
			rtc.h
				sysInit.h
		rtc.h
			sysInit.h
	webserver.h
		rtc.h
			sysInit.h
		philipsHue.h
			sysInit.h
		nixie.h
			rtc.h
		utils.h
			sysInit.h

Websockets server stalls on WiFi scan

Due to its implementation, the websockets instance stops responding to client messages during a WiFi scan.
This is a low-priority fix.

Stack smashing protect failure on getTime() with websockets

The MCU sporadically crashes on a getTime() call initiated by the websockets module.

Websockets server broadcasts messages to all clients

Currently, the websockets server sends its messages to all clients.
Whilst this is not a real problem, it would be nice to have the server send their messages to the actual origin.

Crash on FS mount

This has occurred after OTA partition removal and implementation of config files for network settings:

(MCU START)
[i] Spawning tasks...  
[T] FS: Mounting...  
[i] Done with setup().  
[i] Free heap: [T] RTC: Starting setup...299568[T] Nixie: preparing nixie updater...  
.  
[io\lib  
deps\esp32doit-devkit-v1\LittleFS_esp32\src\lfs.c:998:error: Corrupted dir pair at {0x0, 0x1}  
E (80) esp_littlefs: mount failed,  (-84)  
E (83) esp_littlefs: Failed to initialize LittleFS  
[E][LITTLEFS.cpp:56] begin(): Mounting LITTLEFS failed! Error: -1

Time is sometimes invalid

Sometimes, RTClib produces invalid data, either because the RTC produces garbage or due to some other reason.
This leads to the nixie tubes not updating.