Debugging State Machines: LED Indicator??

Hi Everyone,

I'm working on a set of examples of the use of Finite State Machines in more complex projects. I have experience with doing this, and one difficulty in developing the code is tracing the sequence of states and state changes.

When printing stuff to the serial monitor is difficult or affects timing, I have used LED indicators to help understand the current state and see state changes.

A few years ago I found these nifty little plug-in LED strips that are perfect for this. See the example here (The LED strip at the top):


But I can't FIND the doggone things anywhere right now. And I would like to use them in online examples I want to publish, and help people doing this kind of work. Right now I'm deep in a Remote Generator Control project, helping an Engineer friend in Nigeria. I'm using 4 leds showing up to 16 states, and the two more for the critical START and STOP relays.

Anyone seen these? Know of a source?? 2 hours on Amazon / Ebay / Banggood didn't make it...

Any suggestions / pointers appreciated!!

They look like basic LEDs with limiting resistors with a common ground. Easy enough to make/solder with some perf board.

I’ve seen them. It started me thinking about what vertical boards you could do, in other words, using only one side of the pin rows. But there’s actually more important pins on the other side, like the power pins. You have the analog or digital pins there too. I now remember running such a vertical board plugged into the power pins and used some of A0-A5 to support a 433 MHz transmit and receive. The pins were the 90 degree kind, to make the board stand upright. One minor mod, that turned out to be great when debugging, was a hardware connected LED on the transmitter.

Hi Terry



$3.99 for 5

Ah, it does have the PWM's, doesn't it! :) Although, that photo looks like a missed opportunity, if the PWM pins are not the red, green, blue LED... which it looks like. It would give you full colour control of the combination.

Larry! The Guy with the Eyes and the Ideas.....


And now that we know WHAT to Search on: "Rapid Prototyping LED Breadboard" they're on Ebay etc etc...

I want to be able to include one in kits I am working on for Home Automation and Remote/Automatic Generator control.

I appreciate it!

See post #709

I have made the PCBs on the left side of the image, vertical LED helpers.


Larry has thought of (almost) everything in electronics / Arduino!