Three-Digit Seven Segment Display and Driver

Name: Three-Digit Seven Segment Display and Driver
SKU: 33488
Price: 8.00 USD
Availability: OutOfStock

A 3-digit seven segment display and I2C driver board

Designed by jamesfowkes in United Kingdom

Three-Digit Seven Segment Display and Driver 1

Three-Digit Seven Segment Display and Driver 2

Three-Digit Seven Segment Display and Driver 3

Three-Digit Seven Segment Display and Driver 4

Three-Digit Seven Segment Display and Driver 5

Three-Digit Seven Segment Display and Driver 6

Three-Digit Seven Segment Display and Driver 7

$8.00

Out of Stock

Sold out since Jan 28, 2024

A 3-digit seven segment display and I2C driver board

The Basics This is a driver board for the Kingbright BC56-12 LED display (14.2mm digit height). This is a common-cathode, 3-digit display which needs to be multiplexed. I designed a small interface b…

The Basics

This is a driver board for the Kingbright BC56-12 LED display (14.2mm digit height). This is a common-cathode, 3-digit display which needs to be multiplexed.

I designed a small interface board using an ATTINY26 microcontroller. The interface is I2C and has lots of different options for easy control of the display.

This makes it really simple to integrate a display into a project, compared to doing all the multiplexing and GPIO work yourself. Just attach to I2C and power and send some simple commands.

The commands can set the displayed number and decimal points using two different methods. The display can be set to blink on/off at varying rates and also enabled/disabled entirely while preserving the displayed data.

I2C

The I2C address is 0x10.

Each I2C command is a command byte followed by some data

Description	Command Byte	Data Length (Bytes)	Data
Set individual digits	0x00	3	One byte per digit (values 0 to 9)*
Set displayed number	0x01	2 or 3	16-bit integer, plus optional divisor**
Set blink on interval	0x02	2	16-bit integer for on time in milliseconds
Set blink off interval	0x03	2	16-bit integer for off time in milliseconds
Enable/disable display	0x04	1	1 for on, 0 for off

* In individual digit mode, the decimal point for a digit can be turned on by setting the highest bit (0x80) to 1. For example, to set a digit to 9 and also turn on the decimal point, send 0x89.

** In displayed number mode, send an optional divisor byte to turn on a decimal point. Send 100, 10 or 1 to indicate that either the first, second or third decimal points should be turned on.

Examples

0x00, 0x01, 0x02, 0x03 - Set the display to 123 using individual digit command

0x00, 0x01, 0x82, 0x03 - Set the display to 12.3 using individual digit command

0x01, 0x04, 0x1F - Set the display to 500 using display number command (note that 16-bit number is sent LSB first)

0x01, 0x04, 0x1F, 0x64 - Set the display to 5.00 using display number command (input number 500 is divided by 0x64, which is 100, so 5.00 is displayed)

0x02, 0xFA, 0x00 - Set the on time for display blinking to 250ms

0x03, 0xFA, 0x00 - Set the off time for display blinking to 250ms

0x04, 0x01 - Turn the display on

0x04, 0x00 - Turn the display off

Note that the on/off commands take priority over the blinking commands (the display has to be set on for blinking to work).

Firmware

The board comes pre-programmed with the firmware described above. You can view the firmware on my Gitlab. You will need an ISP programmer with a 1.27mm pitch header if you want to make any changes.