IV-22 3-BaseBoard

Description

IV-22 3-BaseBoard is a compact, STM32-based driver board designed specifically for IV-22 3-digit vacuum fluorescent displays. It provides a clean and flexible solution for driving multiplexed IV-22 tubes while offering a simple UART text protocol for easy integration into embedded systems, test setups, or retro-inspired projects.

The board is built around an STM32F030 microcontroller and uses hardware timers for multiplexing, ensuring stable, flicker-free operation. Display content and brightness can be updated in real time over UART using human-readable ASCII commands with CRC protection.

This baseboard is ideal for:

• Embedded developers and hackers
• Retro / VFD / nixie-style display projects
• Bench instruments, clocks, counters, or status displays
• For automotive digital instrument clusters
• UART-controlled displays from PCs, SBCs, or microcontrollers

✔ IV-22 tubes are included
✔ Open protocol, firmware available on GitHub (https://github.com/Sgw32/iv22_baseboard)
✔ No vendor lock-in – easy to extend or reflash

Key Features

• Drives 3 multiplexed IV-22 VFD digits

• STM32F030 microcontroller

• UART control (38400 baud, 8N1)

• ASCII command protocol with XOR CRC

• Floating-point value display support

• Optional leading-zero suppression

• Uses STM32 HAL (CubeMX-generated project)

• Firmware source code provided

Supported UART Commands

• SETVAL:<float> – display numeric value

• SETVNZ:<float> – display value without leading zeros

• SETPWM:<int> – set PWM value (0…65535)

Firmware & Development

• STM32CubeIDE compatible

• Makefile build supported

• Flash via ST-Link / CubeProgrammer

• Example Python and PyQt5 host tools included

This product is intended for electronics-savvy users. Basic knowledge of UART communication and STM32 flashing is recommended.

Device contains 28V source.

IMPORTANT! No warranty is provided to lamps(assumed as “working”, even if lamps failed), as it is a DIY module for fun and experiments. Use at your own risk!

(all other conditions apply to the main module)