Note: The "8-bit LED Thing" is supplied in Kitset form (assembly required). However, I do offer the option of assembling it for you. The base price is for one "8-bit LED Thing" Kitset. Optionally you can include a ST-LINK V2 Compatible Programmer (if you want to re-program the microcontroller). Also, I provide a 4-up discount, so you can save on a bundle of 4x 8-bit LED Things!

8-bit LED Thing - This is pretty cool!

A few years ago, when I was re-discovering my original digital electronics design and breadboard prototyping background, I decided there was a need for a better LED indicator solution.

As most enthusiasts know, it's quite common to hook-up LED's to your digital or microprocessor based creations, to easily see the status at key points within your circuit.

Often, Dual In-Line (DIL) LED Bar Graph displays are used, for displaying the state of parallel data and address Buses, or even individual register contents.

Now, although we love flashing lights and enjoy plenty of digital signal & register content visibility, there are a couple of problems with doing this.

Firstly, it seems quite common to simply hook-up an LED to a signal line (which we wish to monitor), via a current limiting resistor.

This, unfortunately, has the effect of significantly loading the signal that we are monitoring, quite often beyond the datasheet's maximum source or sink current specification.

In addition, if you add a number of LEDs to your creation, you can significantly add to your project's overall power consumption, also creating unplanned voltage-drops across your breadboard's power feed wiring.

Secondly, hooking-up multiple LED's and current limiting resistors, onto your circuit, can be quite a tedious process, with all of the resistors and hook-up wires needed, just to monitor a multi-bit bus or register.

This is where the Digicool Things "8-bit LED Thing" comes to the rescue. It solves all of these issues, along with adding some cool additional capabilities.

What Does the "8-bit LED Thing" Do?

On first look, the "8-bit LED Thing" is a breadboard friendly 8-bit LED Bar display in a wider 16 pin Dual In-Line package.

It is the same length as a Dual In-Line 16 pin IC package, with a 0.5" pin spacing. You can even place them end-to-end on your breadboard, to make 16-bit, or wider, LED Bar displays.

You might say: Huh? Why don't I just use a regular Dual-In-Line 16 pin 8 LED Bar display?

Well, if you did, you would then need 8 current limiting resistors, additional wiring, and face the signal loading and other issues I've just discussed!

The secret behind the "8-bit LED Thing" is that it actually contains the brains of a tiny microcontroller, making it a little smarter than your average LED Bar Display.

Firstly, to use it for displaying the status of up to 8 digital signals, you only need to connect up the two power pins. That is, Ground and your project's 5V or 3.3V power line.

Then, up to 8 digital signals can be monitored just by connecting to any of the 8 pins along one side of the "8-bit LED Thing".

Now, apart from the ease of connection, and no need for current limiting resistors etc, the magic here is that each input presents as only a 1 micro-Amp (1µA) load to the signal being monitored.

Yes, I said that correctly. Only 1 micro-Amp! Effectively, there is no load impact on the monitored signal!

This is due to the fact that these sensing inputs are actually floating, so there is no pull-up or pull-down resistors adding load, or having any impact on your circuit.

However, because of this, do note that if any of the 8 digital level sensing inputs remain unused, then they should by tied to Ground.

In addition to this ease of use, and virtually no load on the signals being monitored, the Display is also efficient, as all the illuminated LED's are charlieplexed.

Now, this is only the start of the 8-bit LED Thing's capabilities.

You see, this is just the "8-bit LED Thing" operating in its default mode, and there are another 7 modes of operation.

8 Modes of Operation!

On the other side of the Display we have some more pins. You already know about the Ground and Power pins.

There are also 2 pins to support microcontroller programming.

In addition, there are also 3 mode control input pins. These mode pins have internal weak pull-ups enabled, so by default (with the pins not connected), we are in mode 7 (with all 3 mode pins pulled high).

So, mode 7 is the default 8 pin digital level signal monitoring mode.

By controlling the mode pins, we can switch to other modes, including a mode that even turns the "8-bit LED Thing" into a Dice!

There are also various scanning display modes. All are explained on the handout that comes with the "8-bit LED Thing".

One common use would be to just pull the Mode 1 pin (M1) low, to cause the LED Bar Display to be a sweep scanner (like the Knight Rider car of the 80's TV series fame), for indicating periods when your project is in standby (for example). But, I'm sure you can use your own imagination!

Why am I Now Offering These?

I've actually been using a number of these 8-bit LED Things with my own projects, for several years now, without previously offering them as a solution for others to use.

You see, I designed and tweaked them before Covid hit. But, just when I was happy that they were complete, and ready for others to also use, Covid hit the global supply chain and the price of the microcontroller chips went up 10 fold!

Recently, I revisited making another batch, and I found that the component prices had since come back down, so the "8-bit LED Thing" was once again cost-viable to offer, for other users to have as much fun with, as I've had.

As an aside, the "8-bit LED Thing" also made a fun design project, as they also represent the physically smallest microcontroller project that I've ever made.

You can also consider the "8-bit LED Thing" as simply a tiny STM8 microcontroller board, which you could also program for your own projects.

As such, I've decided to offer these in Kitset form, so you have the choice of using the bare MCU board, for your own use, or you can simply solder on the supplied LED Bar Display and the gold plated round-pin header strips, to complete your own "8-bit LED Thing".

I've also added an "Assembled" option, where I can assemble them for you, for a small fee.

Re-Programming The Microcontroller

To re-program the microcontroller you can simply use a ST-Link V2 USB Programmer, which is connected to the board with just 4 wires. These are Ground, Power, Reset, and the ST single-pin SWIM interface. SWIM stands for Single Wire Interface Module.

If you don't already have a ST-Link V2 Programmer, and want one to play around with programming the microcontroller yourself, I've offered, as an option, the same ST-Link V2 compatible USB Programmer that I'm using, so you can get one with your "8-bit LED Thing".

Finally, because it's common to use multiple 8-bit LED Things on your breadboard projects (I know I do), I'm offering a 4-up price. So, you can have 4 for a reduced bundle price!

Be sure to watch the linked video, for a demonstration of the "8-bit LED Thing" in operation!

What You Get

These come in Kitset form, so you have the choice of using the bare MCU board (for your own use), or you can simply solder on the supplied LED Bar Display and the gold plated round-pin header strips, to complete your own "8-bit LED Thing".

Included:

• Assembled, Programmed & Tested "8-bit LED Thing" Microcontroller Board
• 8 Segment LED Bar Graph in DIP16 Package
• 20-pin Round-Pin Gold-Plated Header Strip (To cut into 8 + 4 + 3 strips)

Optional: Assembly

• Assembly - if you'd prefer I did it (and you just want the "8-bit LED Thing" ready to go!)

Optional: Programmer

• ST-LINK V2 Compatible STM8 & STM32 USB Programmer (Tested)

Note: To order 1x Programmer with multiple 8-bit LED Things, just add 1x 8-bit LED Thing to your Cart first (with Programmer), then add more 8-bit LED Things to your Cart (without the Programmer). The 4-up price applies for the total quantity in your Cart!

Your "8-bit LED Thing" Kitset order is shipped in a robust cardboard carton with packing, for safe delivery via New Zealand International Air Parcel (see example shipping photo).

Note: Please visit the Documentation link (below) for more information on DigicoolThings, and for details of the various other projects I've been working on (with the prototyping help from the "8-bit LED Thing"!).