Published May 1, 2021 © GPL3+

Easiest Way to Connect Any VFD Serial Display to Arduino

This is a nice retro-look weather station and clock that I made with a POS VFD display for which I did not have any data and information.

IntermediateFull instructions provided7,854

Easiest Way to Connect Any VFD Serial Display to Arduino

Things used in this project

Hardware components

Arduino Nano R3

MyOctopus i2c Barometric Air Pressure Sensor BMP280

Maxim Integrated DS3231M - ±5ppm, I2C Real-Time Clock

Serial VFD POS display

Software apps and online services

Arduino IDE

Hand tools and fabrication machines

Soldering iron (generic)

Solder Wire, Lead Free

Story

The device is very simple to build and contains only a few components:

- Arduino Nano microcontroller

- BMP180 barometric sensor, which is mounted outside the box for more accurate temperature measurement

- DS3231 realtime clock module

- and POS customer VFD display

In this video I will describe how to connect any unknown serial VFD display to the Arduino microcontroller, where the text from the serial monitor is shown on the display.

First we need to connect it to the power supply. For this purpose I reviewed the datasheets for most chips on the board and it is seen that the supply voltage should be 5V. It was easiest and safest to solder the power cords directly to pin 4 (Gnd) and pin 6 (Vcc) of MC 34063 chip. After connecting the power supply, the basic information appears on the display, and we are most interested in Baud Rate, who in this case is 4800.

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Next we need to find out how this display will communicate with the Arduino. Almost every serial display has RS-232 line driver/receiver chip usually max 232 or equivalent. Specifically in this case it is SIPEX SP232 ACP. The datasheets show that the TTL input to the circuit is pin 11. We also need to shorten pins 14 and 13, Transmit data and Receive data. Now we need to connect the TX output from the Arduino to the TTL input of the MAX232 chip pin11. In this case, everything we see on the Arduino serial monitor will be displayed on the VFD display.

For example I made a simple weather station with BMP180 which also contains a clock with DS3231 board. As we can see, the information on the serial monitor should be in one row, and not longer than 40 characters. We do this in the code with the help of Serial.print and Serial.println commands and with a combination of spaces. Finally, the device is mounted in a suitable box made of 5mm PVC board and coated with colored wallpaper.

Code

Arduino Code

#include <Wire.h>
#include <SFE_BMP180.h>
#include <DS3231.h>
SFE_BMP180 bmp180;
DS3231  rtc(SDA, SCL);
int Altitude = 713; //current altitude in meters in my town

void setup() {
  Serial.begin(4800);
  rtc.begin();
  // The following lines can be uncommented to set the date and time
  //rtc.setDOW(WEDNESDAY);     // Set Day-of-Week to SUNDAY
  //rtc.setTime(17, 47, 0);     // Set the time to 12:00:00 (24hr format)
  //rtc.setDate(3, 7, 2021);   // Set the date to January 1st, 2014
  
  bool success = bmp180.begin();

  if (success) {
    Serial.println("BMP180 init success");
  }
}

void loop() {

  char status;
  double T, P;
  bool success = false;

  status = bmp180.startTemperature();
delay(1000);
  if (status != 0) {
  
    status = bmp180.getTemperature(T);

    if (status != 0) {
      status = bmp180.startPressure(3);

      if (status != 0) {
        delay(status);
        status = bmp180.getPressure(P, T);

        if (status != 0) {
          int comp = bmp180.sealevel(P, Altitude);

          Serial.print(" ");
          Serial.print(comp);
          Serial.print(" hPa");

          Serial.print(" * ");
          Serial.print(T);
          Serial.print(" C ");


  // Send date
  Serial.print(rtc.getDateStr());
  Serial.print(" ");
 
  // Send time
  Serial.println(rtc.getTimeStr());
  
        }
      }
    }
  }
}