Buttons on Bald Engineer

5 Voltage divider circuits that go beyond dividing

Wed, 23 Aug 2017 13:19:15 +0000

Hey Newsletter Readers: Looking for Best Resistor Sorting Method? My Bad! Here are some ideas of what you can do with the humble voltage divider. This elementary circuit has a few inventive uses. To be upfront, one of these uses is NOT as a voltage regulator. If you need a voltage regulated, get a voltage regulator! At some point or another, I’ve built all five of these voltage divider circuits. For me, the voltage level shifter is the most common.

Detect short and long button press using millis

Wed, 19 Apr 2017 12:00:48 +0000

To detect a short and long button press using millis can give your project more functionality without adding more buttons. In this line-by-line example, I show how to react to a user pressing a button for a short period (100ms) or a long period (over 500ms). My example changes the blink rate of an LED on short presses. A long button press turns off the LED. In the code, I make use of a struct so that a single variable can be used to track multiple parameters. The benefit of this method is that adding multiple buttons is easy. You could create an array of these tyepdef’d variables.

Arduino: De-Bounce a Button with micros() or millis()

Fri, 13 Dec 2013 12:25:45 +0000

The Arduino is fast, humans are slow. When you push down a button, what seems like a single change to slow humans is really multiple presses to an Arduino. This is known as “bouncing.” Figure 1 is an oscilloscope screenshot showing what could happen when a button is pressed. Figure 1 - All the bouncing! The top trace shows the high-low-high transition of the button press. But notice all of the activity at the start of the high-to-low transition. The bottom trace is a “zoomed-in” view of that area. The button is actually transitioning multiple times before staying low. Internally the contacts are “bouncing.” This could result in false reads. In software, we can ignore these bounces by waiting some period of time after the first transition.

Arduino Internal Pull-Up Resistor Tutorial

Fri, 30 Dec 2011 07:31:32 +0000

When hooking up switches or buttons to an Arduino I/O pin, sometimes the results might appear completely random. Sometimes it will appear as though there is a delay from when the button is pressed until the state of the pin actually changes. Other times the pin’s value will seem to randomly fluctuate from HIGH to LOW. Even more maddening might be as your finger gets closer to the switch, the pin’s state changes! The fix to these problems is simple: use the Arduino Internal Pull-up Resistor. Here’s how they can fix this problem and how you can use them with an Arduino board.

Video Tutorial: Buttons and Pull-Ups

Mon, 19 Dec 2011 05:20:26 +0000

This is a 4-minute video version of the Arduino Pull-Up Tutorial: