VFD Display Setup (Noritake GU140x32F-7000B)

EAS Station™ supports the Noritake GU140x32F-7000B vacuum fluorescent display for showing alert status, system metrics, and scrolling messages. The display connects via RS-232 serial and is managed by the hardware_service.

Supported Hardware

Component	Details
Display	Noritake GU140x32F-7000B (140×32 pixel VFD)
Interface	RS-232 serial (DB9 or USB-serial adapter)
Baud rate	Configurable (default: 38400)
Protocol	Noritake Itron command set
Brightness	8 levels (0–7, 7 brightest)

The GU140x32F uses Noritake's character and graphics display protocol. Other VFD models may work but are not officially supported.

Physical Connection

Direct RS-232 (DB9 Connector)

Connect the VFD's DB9 female connector to your computer's serial port (or a USB-to-RS232 adapter):

VFD Pin	Signal	Computer Pin
2	RXD	TXD (pin 3)
3	TXD	RXD (pin 2)
5	GND	GND (pin 5)

Note: This is a null-modem style connection. If using a straight-through cable, you may need a null-modem adapter.

USB-to-Serial Adapter

For systems without a native serial port (such as Raspberry Pi), use a USB-to-RS232 adapter:

# Verify the adapter is detected
ls /dev/ttyUSB*

# Check kernel driver
dmesg | grep tty | tail -5

Common device paths: /dev/ttyUSB0, /dev/ttyUSB1, /dev/ttyS0.

Grant the eas-station user access to the serial port:

sudo usermod -a -G dialout eas-station

A logout/login or service restart is required for group changes to take effect.

Configuration

Via the Web Interface

Navigate to Admin → Hardware Settings.
Enable the VFD Display toggle.
Set the VFD Serial Port (e.g., /dev/ttyUSB0).
Set the VFD Baud Rate (default: 38400).
Click Save Settings.

Restart the hardware service:

sudo systemctl restart eas-station-hardware.target

Note: VFD settings are stored in the database (hardware_settings table) and managed through the web UI shown above. The eas-config TUI no longer edits hardware settings — its Hardware Integration entry points to the web UI. Legacy VFD_* environment variables in .env are imported once during the initial migration and are not read at runtime afterwards.

VFD Control Dashboard

The VFD control interface is available at /vfd_control in the web UI.

Features

Live status — shows current display content and connection state
Send message — type text to display immediately on the VFD
Brightness control — select a level from 0 (dimmest) to 7 (brightest)
Clear display — blank the VFD
Message history — view the last 10 messages sent to the display
Graphics — draw pixels, lines, rectangles, and progress bars directly

API Endpoints

Method	Path	Description
`GET`	`/api/vfd/status`	Current VFD status and content
`POST`	`/api/vfd/text`	Send text to VFD at a given `(x, y)`
`POST`	`/api/vfd/image`	Display an image on the VFD
`POST`	`/api/vfd/clear`	Clear the display
`POST`	`/api/vfd/brightness`	Set brightness level (`level`, 0–7)
`POST`	`/api/vfd/graphics/pixel`	Draw a single pixel
`POST`	`/api/vfd/graphics/line`	Draw a line
`POST`	`/api/vfd/graphics/rectangle`	Draw a rectangle
`POST`	`/api/vfd/graphics/progress`	Draw a progress bar
`GET`	`/api/vfd/displays`	List recent display history entries

There is no dedicated "test pattern" endpoint — use /api/vfd/text to confirm the connection is working.

Send a message via API:

Note: API-key authentication (X-API-Key) is planned but not yet implemented — see API Key Management. Until it ships, these endpoints require an authenticated browser session (log in first and reuse the session cookie).

curl -X POST \
  -H "Content-Type: application/json" \
  -d '{"text": "TORNADO WARNING", "x": 0, "y": 0}' \
  https://your-eas-station.example.com/api/vfd/text

Alert Display Integration

When the VFD is enabled, the hardware_service automatically displays incoming EAS alerts on the VFD:

Alert received — event code and area description scroll across the display
During broadcast — "ON AIR" indicator shown
Idle — clock, station callsign, or custom message rotates

Alert display behavior is configurable via Admin → Hardware Settings → VFD Alert Display.

Brightness Levels

Level	Enum Name
0 (dimmest)	`LEVEL_0`
1	`LEVEL_1`
2	`LEVEL_2`
3	`LEVEL_3`
4	`LEVEL_4`
5	`LEVEL_5`
6	`LEVEL_6`
7 (brightest)	`LEVEL_7`

Brightness can be changed at any time from the VFD control dashboard or via the API without disrupting the current display content.

Troubleshooting

VFD shows no output

Confirm the serial port path is correct:
```
ls -la /dev/ttyUSB* /dev/ttyS*
```
Verify the baud rate matches the VFD's DIP switch settings (check the hardware manual).
Check the displays service logs (VFD is managed by eas-station-displays.service, not the GPIO service):
```
journalctl -u eas-station-displays.service -f
```

"VFD not available" in the control dashboard

The app_core.vfd module requires pyserial. Verify it is installed:

source /opt/eas-station/venv/bin/activate
python -c "import serial; print(serial.VERSION)"

Install if missing:

pip install pyserial

Display shows garbage characters

Baud rate mismatch is the most common cause. Try 2400, 4800, 9600, and 19200.
Verify RXD/TXD wiring is not swapped.
Check for null-modem vs. straight-through cable mismatch.

Permission denied on serial port

sudo usermod -a -G dialout eas-station
sudo systemctl restart eas-station-hardware.target

VFD works from command line but not from service

The eas-station user may not be in the dialout group when running as a systemd service. Check:

groups eas-station

And confirm the systemd unit does not override the user's supplementary groups.

Serial Adapter Recommendations

For Raspberry Pi deployments, the following USB-to-RS232 adapters are known to work well:

FTDI-based adapters (e.g., StarTech ICUSB232FTN) — most reliable driver support on Linux
Prolific PL2303 adapters — widely available and well-supported
CH340/CH341 adapters — works but requires ch341 kernel module

Avoid chipsets with known Linux compatibility issues (some Prolific knockoffs may have driver problems on newer kernels).

Back to Documentation Index

This document is served from docs/hardware/VFD_DISPLAY_SETUP.md.md in the EAS Station™ installation.