Please note: All our kits will be sold via The Curious Electric Company from now on. This page is for information only. Please visit our shop to see our current range of kits or contact us to discuss your project and how we might be able to help.

This is an all-in-one six digit 7-segment led display unit with an ATmega328 programmed with the Arduino bootloader. The displays can be used to count, time things or display numbers. The display is bright enough to use inside or out. The display is controlled using an SPI, which uses four digital pins from the microcontroller, leaving all the others free. Multiple displays can be connected together using the SPI bus.

This kit is available for £25 (inc P&P within the UK). This product is now out of stock and probably not going to be back in stock, but please email if still interested.

This post is for INFORMATION ONLY

Here at Renewable Energy Innovation, we have been asked to provide visible numeric displays, mainly to show power and energy. This kit came from one of those projects and we decided to create a PCB and put the parts together as a kit which might be useful to other folk.

The unit itself is based up the AS1107 8 digit 7-segment LED driver (which is a replacement part for the (more popular) MAX7219 IC). This does most of the hard work on the board, as it maintains the LED display with the data sent to it. It also controls the intensity of the display.

The AS1107 is interfaced via SPI (Serial Peripheral Interface) bus. This is connected to an ATMega328 with an Arduino Uno bootloader. This means we can communicate to it using programs written with the Arduino IDE. It is connected with the standard SPI connections of:

  • Serial Clock -> Arduino Pin 13
  • Master In Slave Out -> Arduino Pin 12
  • Master Out Slave In -> Arduino Pin 11
  • Chip Select -> Arduino Pin 10

The various standard Arduino Input/Output pins are all available as connector pads (D0-13 and A0-5). These can be used as inputs for counters and timers.

Note: To program the Arduino, a standard FTDI USB-Serial lead is required. Update 25/3/14: We now also sell a re-programming lead which works with this kit, here.

Also a number of these units can be interfaced to one Arduino (each with a different Chip Select) and hence lots of information can be displayed.

Here is the example code (available below) in action:

Buy one here:

This kit is available here, with payment via paypal. The cost is £25 (including p&p within the UK). This includes a programmed ATmega328 and 6 x 7segment LED units.

Update 25/2/15: This product is now out of stock and probably not going to be back in stock, but please email if still interested.

6 Digit LED Display Kit

Update 25/3/14: We now also sell a re-programming lead which works with this kit, here.

A GITHUB repository of the design files is linked here.

Kit Information

This is a relatively simple to put together kit, although it does have one surface mount IC to solder. The kit includes the following parts:

Note: You will need: soldering iron, solder, wire cutters.


The construction instructions are available here:

Download the PDF file .

Circuit Schematics

Here is the circuit schematic:

Download the PDF file .

Parts List

The kit includes the following parts: (As noted, you will also need an FTDI USB/Serial Cable)


Reference Description Reference Description
AFF1-6 Battery holder P4 Mounting hole
C1 100uf electrolytic capacitor P5 Mounting hole
C2 100uf electrolytic capacitor P6 Mounting hole
C3 100nf P8 FTDI header (6-pin)
C4 100nf P9 Analog 0-5 pads
C5 22pF P10 Digital 8-13 pads
C6 22pF P11 Digital 0-7 pads
IC1 AS1107 SPI LED Driver R1 10k resistor
IC2 ATMEGA328P-P – UNO boot-loader R2 10k resistor
28 pin DIL socket SW1 Reset switch
P1 SPI Input connector (not supplied) X1 16MHz Crystal
P2 Mounting hole PCB
P3 SPI Output connector (not supplied)

Arduino Code

The code for this project was written using the Arduino bootloader and IDE. (Note: It was written on version 1.05 of the IDE and is untested on other versions).

This project assumes some knowledge of the Arduino platform. If you do not have this then please start with the numerous examples available within the Arduino community.

Here are the examples, which you will need to download and add to your Arduino sketchbook:

The code has numerous comments and is based upon ShiftOut code from the Arduino reference website.

KiCAD design files

This is a fully open-source project. The PCB and schematic for this project were drawn using the open-source KiCAD electronics design package.

The full KiCAD PCB files (schematic and board) are available within this GITHUB repository. The direct Gerber files are also included.

Here is the PCB and layout design:

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