SparkFun Qwiic Alphanumeric Display Hookup Guide

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Contributors: Ell C, MAKIN-STUFF
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Introduction

Seven segment displays are SO 2020. I mean, we see them in our clocks, ovens, and microwaves on the daily. But what happens when you add more segments to each digit? You can upgrade your appliances and let everyone know how you REALLY feel. Introducing SparkFun's newest Qwiic-Enabled Alphanumeric Display in Pink, Green, Blue, Red, Purple, and White. Customize that microwave alert - "Your food is done, fool!" Or hack those oven messages - "I pity the fool that doesn't pre-heat!" These fourteen-segment digits allow you display all sorts of numbers, characters, and symbols. Let's jump in and have a look, shall we?

SparkFun Qwiic Alphanumeric Display - Pink

SparkFun Qwiic Alphanumeric Display - Pink

COM-16919
$9.95
SparkFun Qwiic Alphanumeric Display - Green

SparkFun Qwiic Alphanumeric Display - Green

COM-18566
$9.95
1
SparkFun Qwiic Alphanumeric Display - Red

SparkFun Qwiic Alphanumeric Display - Red

COM-16916
$9.95
SparkFun Qwiic Alphanumeric Display - Blue

SparkFun Qwiic Alphanumeric Display - Blue

COM-16917
$9.95
SparkFun Qwiic Alphanumeric Display - Purple

SparkFun Qwiic Alphanumeric Display - Purple

COM-16918
$9.95
SparkFun Qwiic Alphanumeric Display - White

SparkFun Qwiic Alphanumeric Display - White

COM-18565
$9.95

Required Materials

You will need a microcontroller to control the Qwiic Alphanumeric Display in order to follow along with this tutorial. Below are a few options that come Qwiic-enabled out of the box:

SparkFun Qwiic Pro Micro - USB-C (ATmega32U4)

SparkFun Qwiic Pro Micro - USB-C (ATmega32U4)

DEV-15795
$19.95
4
SparkFun RedBoard Qwiic

SparkFun RedBoard Qwiic

DEV-15123
$19.95
10
SparkFun Thing Plus - ESP32 WROOM

SparkFun Thing Plus - ESP32 WROOM

WRL-15663
$20.95
7
SparkFun RedBoard Artemis

SparkFun RedBoard Artemis

DEV-15444
$19.95
8

If your chosen microcontroller is not already Qwiic-enabled, you can add that functionality with one or more of the following items:

SparkFun Qwiic Adapter

SparkFun Qwiic Adapter

DEV-14495
$1.50
1
SparkFun Qwiic Shield for Arduino

SparkFun Qwiic Shield for Arduino

DEV-14352
$6.95
6

You will also need at least one Qwiic cable to connect your Alphanumeric Display to your microcontroller.

Qwiic Cable - 100mm

Qwiic Cable - 100mm

PRT-14427
$1.50
Qwiic Cable - 500mm

Qwiic Cable - 500mm

PRT-14429
$1.95
1
Qwiic Cable - 50mm

Qwiic Cable - 50mm

PRT-14426
$0.95

Qwiic Cable - 200mm

PRT-14428

Suggested Reading

If you aren't familiar with the Qwiic system, we recommend reading here for an overview:

Qwiic Connect System

We would also suggest reading through the following tutorials if you are not familiar with the concepts covered in them:

Serial Communication

Asynchronous serial communication concepts: packets, signal levels, baud rates, UARTs and more!

I2C

An introduction to I2C, one of the main embedded communications protocols in use today.

Hardware Overview

As mentioned in the introduction, the Qwiic Alphanumeric Displays use the VK16K33 LED driver chip to control the segments. In this section of the guide we'll go into more detail on the LED driver and the display, as well as the other components included on the board.

VK16K33 LED Driver

The Qwiic Alphanumeric Display boards use the VK16K33 LED driver chip to control the segments. The VK16K33 is a memory mapping and multifunction LED controller driver with a maximum display segment number of 128 patterns (16 segments and 8 commons) and a 13×3 matrix key scan circuit. There's an integrated RC oscillator and a 16-step dimming circuit as well. More information can be found in the VK16K33 Datasheet.

LED Driver on the back of the board

Alphanumeric Display

Look at all those beautiful segments ready to display (almost) whatever your heart desires!

Display screen on the front of the board

Qwiic

Our Qwiic Ecosystem makes sensors pretty much plug and play. There are two Qwiic connectors on either side of the Alphanumeric Display board to provide power and I2C connectivity simultaneously.

The default I2C address of the board is 0x70. Additional addresses are available - see the Jumpers section below.

Qwiic connectors on either side of the back of the board

I2C Address Jumpers

Two jumpers have been provided to allow you to choose the I2C address of the peripheral. See the table below for configuration details.

A0 and A1 jumpers are on the far right of the back of the board

Address A0 A1
0x70 Open Open
0x71 Closed Open
0x72 Open Closed
0x73 Closed Closed

I2C Bus Resistor Jumper

The Qwiic Alphanumeric Display Breakout has onboard I2C pull up resistors; if multiple sensors are connected to the bus with the pull-up resistors enabled, the parallel equivalent resistance will create too strong of a pull-up for the bus to operate correctly. As a general rule of thumb, disable all but one pair of pull-up resistors if multiple devices are connected to the bus. If you need to disconnect the pull up resistors they can be removed by cutting the traces on the corresponding jumpers highlighted below.

Jumper is on the lower left side of the back of the board

I2C Pins

If you've got mad soldering skillz and really want to access the I2C pins, we've made these bad boys available to you. Check it:

  • C - SCL
  • D - SDA
  • 3 - 3.3V
  • G - GND

Four pins on the back of the board are highlighted just to the right of the Driver Chip

Board Outline

Each Alphanumeric Display Breakout board measures 1.6" x 1.1".

The board measures 1.6" x 1.1"

Hardware Hookup

Using the Qwiic system, assembling the hardware is a breeze. All you need to do is connect your SparkFun Qwiic Alphanumeric Display to your chosen development board with a Qwiic cable or adapter cable.

Alphanumeric plugged into RedBoard via Qwiic cables

If you decide to use the PTH pins broken out on the display you will need to solder some headers to them. If you are not familiar with through-hole soldering take a look at this tutorial:

How to Solder: Through-Hole Soldering

September 19, 2013

This tutorial covers everything you need to know about through-hole soldering.

Pins are soldered to the extra PTH

With the display connected to your microcontroller it's time to get started using the SparkFun Alphanumeric Display Library!

Alphanumeric Display Arduino Library

Note: Make sure you are using the latest stable version of the Arduino IDE on your desktop. If this is your first time using Arduino IDE, library, or board add-on, please review the following tutorials.

Before we get started, we'll need to download and install SparkFun's Alphanumeric Display Arduino library. You can use the Arduino Library Manager by searching "SparkFun Alphanumeric Display" to automatically install. Or you can download the library and install it using the button below.

Before we get started developing a sketch, let's look at the available functions of the library.

  • bool setBrightness(uint8_t duty); --- This sets the brightness for all units
  • setBrightnessSingle(uint8_t displayNumber, uint8_t duty); --- This sets the brightness for a single unit
  • setBlinkRate(float rate); --- Set the refresh rate for all units.
  • setBlinkRateSingle(uint8_t displayNumber, float rate); --- Set the refresh rate for a single unit
  • displayOn(); --- Turn all display units on
  • displayOff(); --- Turn all display units off
  • displayOnSingle(uint8_t displayNumber); --- Turn a single display unit on
  • displayOffSingle(uint8_t displayNumber); --- Turn a single display unit off
  • setDisplayOnOff(uint8_t displayNumber, bool turnOnDisplay); --- Set or clear the display on/off bit
  • enableSystemClock(); --- Turn on the system oscillator for all displays on the I2C bus
  • disableSystemClock(); --- Turn off the system oscillator for all displays on the bus
  • enableSystemClockSingle(uint8_t displayNumber); --- Turn on the system oscillator for normal operation mode
  • disableSystemClockSingle(uint8_t displayNumber); --- Turn off the system oscillator for standby mode
  • illuminateSegment(uint8_t segment, uint8_t digit); --- Given a segment and a digit, set the matching bit within the RAM of the Holtek RAM set
  • illuminateChar(uint16_t disp, uint8_t digit); --- Given a binary set of segments and a digit, store this data into the RAM array
  • printChar(uint8_t displayChar, uint8_t digit); --- Print a character, for a given digit, on display
  • updateDisplay(); --- Push the contents of displayRAM out to the various displays in 16 byte chunks
  • defineChar(uint8_t displayChar, uint16_t segmentsToTurnOn); --- Update the list to define a new segments display for a particular character
  • getSegmentsToTurnOn (uint8_t charPos); --- Get the character map from the definition list or default table
  • decimalOn(); --- Turn the decimal on for all displays on bus
  • decimalOff(); --- Turn the decimal off for all displays on bus
  • decimalOnSingle(uint8_t displayNumber); --- Turn the decimal point on for a single display
  • decimalOffSingle(uint8_t displayNumber); --- Turn the decimal point off for a single display
  • setDecimalOnOff(uint8_t displayNumber, bool turnOnDecimal); --- Set or clear the decimal on/off bit
  • colonOn(); --- Turn the colon on for all displays on the bus
  • colonOff(); --- Turn the colon off for all displays on the bus
  • colonOnSingle(uint8_t displayNumber); --- Turn the colon on for a single display
  • colonOffSingle(uint8_t displayNumber); --- Turn the colon off for a single display
  • setColonOnOff(uint8_t displayNumber, bool turnOnColon); --- Set or clear the colon on/off bit
  • shiftRight(uint8_t shiftAmt = 1); --- Shift the display content to the right one digit
  • shiftLeft(uint8_t shiftAmt = 1); --- Shift the display content to the left one digit

Arduino Examples - The Basics

Now that we have our library installed, we're ready to run some examples. The library currently comes with a set of 10 examples to get you started on your way. Let's look at the first few examples!

Example_01_PrintString

Once the library is installed, go ahead and open up File->Examples->SparkFun Qwiic Alphanumeric Display Library->Example_01_PrintString.

Alternatively, you can copy and paste the code below to a shiny new Arduino file:

    language:c
/*****************************************************************************************
 * This example tests illuminating whole 4 letter strings on the 14-segment display.
 * 
 * Priyanka Makin @ SparkFun Electronics
 * Original Creation Date: February 3, 2020
 * 
 * SparkFun labored with love to create this code. Feel like supporting open source hardware?
 * Buy a board from SparkFun! https://www.sparkfun.com/products/16391
 * 
 * This code is Lemonadeware; if you see me (or any other SparkFun employee) at the 
 * local, and you've found our code helpful, please buy us a round!
 * 
 * Hardware Connections:
 * Attach Red Board to computer using micro-B USB cable.
 * Attach Qwiic Alphanumeric board to Red Board using Qwiic cable.
 * 
 * Distributed as-is; no warranty is given.
 ****************************************************************************************/
#include <Wire.h>

#include <SparkFun_Alphanumeric_Display.h> //Click here to get the library: http://librarymanager/All#SparkFun_Qwiic_Alphanumeric_Display by SparkFun
HT16K33 display;

void setup()
{
  Serial.begin(115200);
  Serial.println("SparkFun Qwiic Alphanumeric - Example 1: Print String");

  Wire.begin(); //Join I2C bus

  if (display.begin() == false)
  {
    Serial.println("Device did not acknowledge! Freezing.");
    while (1);
  }
  Serial.println("Display acknowledged.");

  display.print("Milk");
}

void loop()
{
}

Once you have the code, make sure you've got the correct port selected, and then go ahead and click on the upload button. If all goes well, you'll see your Display light up with "Milk"!

"Milk" is displayed on the alphanumeric board

Example_02_TurnOnOneSegment

This example lights up a single segment on the display. Head on back to your File Menu and open up File->Examples->SparkFun Qwiic Alphanumeric Display Library->Example_02_TurnOnOneSegment.

Alternatively, you can copy and paste the code below to a shiny new Arduino file:

language:c
/*******************************************************************************************
 * This example tests illuminating individual segments of the display. Pass in the segment
 * and digit you wish to illuminate to illuminateSegement().
 * 
 * Priyanka Makin @ SparkFun Electronics
 * Original Creation Date: January 31, 2020
 * 
 * SparkFun labored with love to create this code. Feel like supporting open source hardware?
 * Buy a board from SparkFun! https://www.sparkfun.com/products/16391
 * 
 * This code is Lemonadeware; if you see me (or any other SparkFun employee) at the 
 * local, and you've found our code helpful, please buy us a round!
 * 
 * Hardware Connections:
 * Attach Red Board to computer using micro-B USB cable.
 * Attach Qwiic Alphanumeric board to Red Board using Qwiic cable.
 * 
 * Distributed as-is; no warranty is given.
 *****************************************************************************************/
#include <Wire.h>

#include <SparkFun_Alphanumeric_Display.h>  //Click here to get the library: http://librarymanager/All#SparkFun_Qwiic_Alphanumeric_Display by SparkFun
HT16K33 display;

void setup()
{
  Serial.begin(115200);
  Serial.println("SparkFun Qwiic Alphanumeric - Example 2: Turn On One Segment");
  Wire.begin(); //Join I2C bus

  //check if display will acknowledge
  if (display.begin() == false)
  {
    Serial.println("Device did not acknowledge! Freezing.");
    while(1);
  }
  Serial.println("Display acknowledged.");

  display.illuminateSegment('A', 0);
  display.illuminateSegment('L', 1);
  display.illuminateSegment('I', 2);
  display.illuminateSegment('G', 3);
  display.updateDisplay();
}

void loop()
{
}

As before, once you have the code, make sure you've got the correct port selected, and then go ahead and click on the upload button. You won't need your serial monitor for this one though, unless you want it. If all goes well, you should see your display light up like so:

One segment of each display bit is lit up

It looks weird, but it's one segment of each letter lit up.

Example_03_PrintChar

Let's print some stuff! Grab Example 3 by going to File->Examples->SparkFun Qwiic Alphanumeric Display Library->Example_03_PrintChar.

Alternatively, you can copy and paste the code below to a shiny new Arduino file:

language:c
/*****************************************************************************************
 * This example tests illuminating whole characters on the 14-segment display.
 * 
 * Priyanka Makin @ SparkFun Electronics
 * Original Creation Date: February 3, 2020
 * 
 * SparkFun labored with love to create this code. Feel like supporting open source hardware?
 * Buy a board from SparkFun! https://www.sparkfun.com/products/16391
 * 
 * This code is Lemonadeware; if you see me (or any other SparkFun employee) at the
 * local, and you've found our code helpful, please buy us a round!
 * 
 * Hardware Connections:
 * Attach Red Board to computer using micro-B USB cable.
 * Attach Qwiic Alphanumeric board to Red Board using Qwiic cable.
 * 
 * Distributed as-is; no warranty is given.
 *****************************************************************************************/
#include <Wire.h>

#include <SparkFun_Alphanumeric_Display.h>  //Click here to get the library: http://librarymanager/All#SparkFun_Qwiic_Alphanumeric_Display by SparkFun
HT16K33 display;

void setup()
{
  Serial.begin(115200);
  Serial.println("SparkFun Qwiic Alphanumeric - Example 3: Print Character");
  Wire.begin(); //Join I2C bus

  //check if display will acknowledge
  if (display.begin() == false)
  {
    Serial.println("Device did not acknowledge! Freezing.");
    while(1);
  }
  Serial.println("Display acknowledged.");

  display.printChar('W', 0);
  display.printChar('H', 1);
  display.printChar('A', 2);
  display.printChar('T', 3);

  display.updateDisplay();
}

void loop(){
}

Check your port, and then click on the upload button. Voila! Are you starting to get the picture?

"WHAT" is displayed

This is just the beginning - there are more examples to get you going with your SparkFun Qwiic Alphanumeric Display. We won't go through them all here, but feel free to tinker with these to see what all you can come up with!

If you haven't downloaded the library yet, get it either here or by clicking on the link below and get hackin!

Arduino Examples - The Fun Stuff

Okay. You got the basics done - you can light up segments, yes? Now lets do a couple of fun things!

Example_08_MultiDisplay

This example tests printing across multiple displays. In order to make this example work, you'll need to do some soldering on the jumpers on the back of the board. For this example, we'll use 0x70 and 0x71 as the addresses, so the jumpers for the second display should look like this:

A0 Jumper is soldered together


Once your jumper is soldered, go ahead and hook your boards together with your Qwiic cables and plug em on into your RedBoard.

Image of RedBoard daisy chained to two Alphanumeric boards via Qwiic cables

Once your hardware is ready to go, head back to your File Menu and open up File->Examples->SparkFun Qwiic Alphanumeric Display Library->Example_08_MultiDisplay.

Alternatively, you can copy and paste the code below to a shiny new Arduino file:

language:c
/**************************************************************************************
 * This example tests printing across multiple alpha displays.
 * 
 * Priyanka Makin @ SparkFun Electronics
 * Original Creation Date: February 26, 2020
 * 
 * SparkFun labored with love to create this code. Feel like supporting open source hardware?
 * Buy a board from SparkFun! https://www.sparkfun.com/products/16391
 * 
 * This code is Lemonadeware; if you see me (or any other SparkFun employee) at the
 * local, and you've found our code helpful, please buy us a round!
 * 
 * Hardware Connections:
 * Attach Red Board to computer using micro-B USB cable.
 * Attach Qwiic Alphanumeric board to Red Board using Qwiic cable. 
 *  Don't close any of the address jumpers so that it defaults to address 0x70.
 * Attach a second Alphanumeric display using Qwiic cable.
 *  Close address jumper A0 so that this display's address become 0x71.
 * 
 * Distributed as-is; no warranty is given.
 *****************************************************************************************/
#include <Wire.h>

#include <SparkFun_Alphanumeric_Display.h>  //Click here to get the library: http://librarymanager/All#SparkFun_Qwiic_Alphanumeric_Display by SparkFun
HT16K33 display;

void setup() {
  Serial.begin(115200);
  Serial.println("SparkFun Qwiic Alphanumeric - Example 8: Multi Display");
  Wire.begin(); //Join I2C bus

  //check if displays will acknowledge
  //The first address in the begin() function should be the left-most display, traveling to the right from there
  //This is how the string will print across displays, reading from left to right.
  if (display.begin(0x70, 0x71) == false)
  {
    Serial.println("Device did not acknowledge! Freezing.");
    while(1);
  }
  Serial.println("Displays acknowledged.");

  display.print("Get Milk");
}

void loop() 
{
}

Once you've got your code, make sure you've got the correct port selected, and then go ahead and click on the upload button. You should see the following:

GET Milk is displayed on multiple boards

Example_09_ScrollingString

This example SCROLLS! Let's start by plugging your Alphanumeric board into your RedBoard with your handy dandy Qwiic cables.

Once your hardware is ready to go, head back to your File Menu and open up File->Examples->SparkFun Qwiic Alphanumeric Display Library->Example_09_ScrollingString.

Alternatively, you can copy and paste the code below to a shiny new Arduino file:

language:c
/**************************************************************************************
 * This example tests scrolling functionality of alphanumeric displays.
 * 
 * Priyanka Makin @ SparkFun Electronics
 * Original Creation Date: February 26, 2020
 * 
 * SparkFun labored with love to create this code. Feel like supporting open source hardware?
 * Buy a board from SparkFun! https://www.sparkfun.com/products/16391
 * 
 * This code is Lemonadeware; if you see me (or any other SparkFun employee) at the
 * local, and you've found our code helpful, please buy us a round!
 * 
 * Hardware Connections:
 * Attach Red Board to computer using micro-B USB cable.
 * Attach Qwiic Alphanumeric board to Red Board using Qwiic cable. 
 *  Don't close any of the address jumpers so that it defaults to address 0x70.
 * Attach a second Alphanumeric display using Qwiic cable.
 *  Close address jumper A0 so that this display's address become 0x71.
 * 
 * Distributed as-is; no warranty is given.
 *****************************************************************************************/
#include <Wire.h>

#include <SparkFun_Alphanumeric_Display.h>  //Click here to get the library: http://librarymanager/All#SparkFun_Qwiic_Alphanumeric_Display by SparkFun
HT16K33 display;

void setup() {
  Serial.begin(115200);
  Serial.println("SparkFun Qwiic Alphanumeric - Example 9: Scrolling String");
  Wire.begin(); //Join I2C bus

  //check if displays will acknowledge
  if (display.begin(0x70) == false)
  {
    Serial.println("Device did not acknowledge! Freezing.");
    while(1);
  }
  Serial.println("Display acknowledged.");

  display.print("MILK");
}

void loop() 
{  
  delay(300);
  display.shiftLeft();
  //Alternatively - you could also shift the string to the right
  //display.shiftRight();
}    

Once you've got your code, make sure you've got the correct port selected, and then go ahead and click on the upload button. You should see the following:

GIF of scrolling "Milk"

Troubleshooting

Resources and Going Further

Congratulations! Now that you've got your Alphanumeric Display(s) up and running, you can hack that boring ol' microwave message with something more "fool" proof! YES!

If you want or need information on your Alphanumeric Display, check out some of the resources below:

Need inspiration? Check out some of these Qwiic related tutorials:

I2C

An introduction to I2C, one of the main embedded communications protocols in use today.

Qwiic Shield for Arduino & Photon Hookup Guide

Get started with our Qwiic ecosystem with the Qwiic shield for Arduino or Photon.

Pi Servo pHAT (v2) Hookup Guide

This hookup guide will get you started with connecting and using the Pi Servo pHAT on a Raspberry Pi.

Qwiic SHIM Kit for Raspberry Pi Hookup Guide

Get started with the Serial LCD with RGB backlight and 9DoF IMU (ICM-20948) via I2C using the Qwiic system and Python on a Raspberry Pi! Take sensor readings and display them in the serial terminal or SerLCD.