ELECTRONIC PROJECTS

A 4017 decade counter connected to a speaker via a 555 timer. The audio is being used as a trigger for the 555 timer, which in turn advances the counter circuit. I don't think it's wired quite right yet, as it mostly seems to react to the lower-frequency, louder audio.

A 4017 decade counter connected to a speaker via a 555 circuit.

Here's a 4017 decade counter set up without a 555 timer for sync. I'm just shaking it, and that's causing enough of a pulse to advance the count.

I'm also thinking of wiring 1/4" inputs into the switch boxes, that way various devices can be plugged in to override the timer circuit, like microphones or electric instruments. Pretty much anything that can create a pulse. That way I'll be able to have each controller running at a different rate.

It works! The combination LED matrix / keyboard matrix circuit board I made is working. Now that I know the basic concept is okay, I'll start making the parts for 10x10 LED boards controlled by 10x10 switches. Everything's going to be getting about eleven times more complicated.

This time, I scrubbed the heck out of the copper with some abrasive cleaner, and I used a page from a magazine to print the board pattern. I did have to touch up a few traces with a Sharpie. After about 45 minutes, the vinegar, hydrogen peroxide & salt solution worked!

My first attempt at the laser printer method of circuit board making - didn’t work out. I’ll try again tomorrow with some different paper and a more thorough cleaning of the copper board. I thought this might not turn out so good, so I used some leftover board that’s been in my project-box since the 1990’s. I can almost see some stubborn fingerprints in the problem areas.

/*   Blink   Turns on an LED on for one second, then off for one second, repeatedly.     This example code is in the public domain.  */   // Pin 13 has an LED connected on most Arduino boards. // give it a name: int led = 13; // the setup routine runs once when you press reset: void setup() {                   // initialize the digital pin as an output.   pinMode(led, OUTPUT);     } // the loop routine runs over and over again forever: void loop() {   digitalWrite(led, HIGH);   // turn the LED on (HIGH is the voltage level)   delay(1000);               // wait for a second   digitalWrite(led, LOW);    // turn the LED off by making the voltage LOW   delay(1000);               // wait for a second }

My generic Arduino showed up in the mail today - time to track down some tutorials!

I ordered some old Soviet 102-pin hermetic connections and they arrived in this box!

Here's a breadboard test for a 3x3 LED matrix controlled by a 3x3 keyboard matrix.