Tutorial on schematics basics
The funny thing about schematics is that they are much easier to draw than they are to read. There are many common circuits. When an experienced engineer looks at them, it’s like a second language. When someone less experienced looks at them, it looks like random lines and symbols thrown together at the last-minute. (Or maybe that’s just the schematics *I* draw.)
Other than reading Schematic Symbols themselves, one of the basic skill necessary to read a schematic is recognizing series and parallel circuits.
In short if the same current flows through all the parts, they are in series. While if current has different paths, they are in parallel. Keep reading to dive into this tutorial on how ohm’s law applies to series and parallel circuits.
How to blink (or flash) a LED without delay() and detect button pushes
One of the limitations of the delay() function is that nothing else can really be done. This presents a problem when you want to flash a LED while waiting for a pushbutton to be pressed.
Flashing the LED with millis() and using a flag variable to find if the LED should be flashing solves this problem.
Consider this another example to my virtual millis() cookbook.
Learning to a breadboard is critical when adding electronics to a project. A skill often overlooked is how to use breadboard jumper wires correctly. For example, when I breadboard a circuit I only use Red, Green, or Blue for positive voltages and Black for ground. Other colors, it depends on the functions of the wire. The idea is to keep it clear when I look at the board, what each wire is doing.
This video from Make is a great overview of how to develop a skill, or habit, around using breadboard jumper wires in your circuit.
For more information, there is a short writeup on their web site as well.
Engineers make a schematic to explain their circuits.
One time I was looking for a non-tourist pub in Japan. I asked someone for help. She said, “I’m sorry, but I do not speak good English. I will bring my friend and she will draw you a map.” (Exact quote!) The map her friend drew, gave directions to a bar with a “Neon Yellow Sing.” She meant sign…
The map was the method we used to communicate with each other, even though we didn’t both speak English. With this crude but effective map, I could find my next
drinking place destination.
Schematics are the same as this map. Even if you don’t speak the same language, you can communicate how a circuit works when you make a schematic.
Use one of these five tools, when you need to a document a circuit or when you need to ask for help.
When learning to use an Arduino, you have two things to learn: programming and hardware. In the past, I’ve taught some classes on how to program the Arduino. These are the slides I used to explain what the Arduino “Language” is, basic debugging concepts, how to use variables, and basic structures.
An Open Source IDE for TI’s line of MSP430-based boards. Based on the same software as the Arduino project, Energia brings easy of use to an awesome family of microcontrollers.
Does Energia stack up as one of the Arduino alternatives?
Previously I wrote it off because of the Windows-centric software. In fact, I made my first “review” video based on it. (I’m a Mac / Linux guy.)
Arduino pinMode on Analog Inputs
All Arduino boards contain analog and digital pins. The Arduino functions have different calls depending on the pin type. For example, when analogWrite() is called, an analog input pin is automatically changed from a digital input (or output) into an analog input. For this reason, it isn’t actually necessary to call pinMode() on the pin. However, when I write Arduino Sketches, I still put a pinMode(INPUT, A0) in setup anyway.
Using a bread board Arduino see what happens when you skip a decoupling capacitor or two
To save time, breadboard pins, or just lack of knowledge people try to skip adding decoupling capacitors to a circuit. Either on IRC or in Forums you can almost always see it coming: “randomly, my stops working” And then, “what do you mean decoupling capacitors”, question.
This isn’t the most scientific testing, but here are some really unexpected measurements with just a breadboard Arduino. The only capacitors I started with were the two 22pF from crystal to ground and the capacitor connected to RESET for Auto-RESET.
Keep reading to find out what happen when I added a 100nF and a 1µF cap. A bunch of scope traces and surprising results follow.
March 29, 2015