---
description: "Vacuum fluorescent display with an ESP"
created: 2025-08-21
---

## Resources

- [WD202 User manual](https://www.touchdynamic.com/wp-content/uploads/2021/06/wd202.pdf)
- [WD202A User manual (contains RJ45 pinout)](https://manualzz.com/doc/html/11817581/digipos-wd-202a-customer-display-user-s-manual)
- [Link to code git repo](https://git.node5.net/firmware/vfd/)

![VFD from the front, one line showing a UNIX timestamp and another line showing a human readable datetime](main.webp)

Got an old VFD from a Point Of Sale device. The kind found in price tally displays in supermarkets.

It uses RS232 to communicate,
so you need a TTL to RS232 converter for the display to recognise the signal from a micro controller.
Which convents the ESPs from 3.3v logic -> -15 to 15 volt.

## --> Attribution: oliver@labitat.dk made the hardware awesome <--

![](back%20pcb%20full%20view.webp)
![](backside.webp)
![](barrel%20jack.webp)
![](dip%20switches.webp)
![](esp-01%20connection.webp)
![](modules.webp)
![](modules%20top.webp)
![](rj45.webp)

![](circuit_image.svg)

[Link to circuit diagram - cirkitdesigner.com](https://app.cirkitdesigner.com/project/05cf3635-211d-451e-8c80-614e9fb4ede3)

```cpp
#include <FastLED.h>
#include <ESP8266WiFi.h>
#include <ezTime.h>

Timezone CopenhagenTime;

void setup() {
  Serial.begin(9600);

  Serial.write(0x0C); // Clear display
  Serial.print("VFD display\n");
  Serial.print("Starting\n");

  WiFi.setHostname(HOSTNAME);
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);

  Serial.write(0x0C); // Clear display
  Serial.printf("Hostname: %s\n", HOSTNAME);
  Serial.printf("Connecting to: %s\n", WIFI_SSID);
  while (WiFi.status() != WL_CONNECTED)
  {
    delay(1000);
    Serial.print('.');
  }

  Serial.write(0x0C); // Clear display
  Serial.println("Connected, IP address: ");
  Serial.println(WiFi.localIP());
  delay(1000);

  waitForSync();
  CopenhagenTime.setLocation("Europe/Copenhagen");

  Serial.write(0x0C); // Clear display
}

void loop() {
  // Get Unix epoch timestamp
  char buffer [3];
  sprintf(buffer,"%03d",ms());
  String milliEpoch = String(now()) + buffer;
  Serial.println(milliEpoch);

  delay(50);
  // https://github.com/ropg/ezTime#getting-date-and-time
  // 16;36;15 Sat 16 Aug 33
  String time_formatted = CopenhagenTime.dateTime("H:i:s D d M");
  Serial.println(time_formatted);

  events(); // Needed to update time continuously
}
```