PID? What is it?

Wikipedia says that a proportional–integral–derivative controller (PID controller) is a generic control loop feedback mechanism (controller) widely used in industrial control systems – a PID is the most commonly used feedback controller. A PID controller calculates an "error" value as the difference between a measured process variable and a desired setpoint. The controller attempts to minimize … Continue reading PID? What is it?

Using a Transistor to Control an LED or anything

For my LCC project I decided to use a 2N4401 NPN transistor to control status LEDs and AC Switches. I did this so that the power draw from the Arduino chip would be as low as possible. Below is a diagram of how this works. I used a 2N4401 NPN transistor that "turns on" when … Continue reading Using a Transistor to Control an LED or anything

Slow Button/Switch Reaction

On my last project- which still isn't done yet- the buttons for changing the temp display are very unresponsive. The reason of course is because the Arduino has to loop through all the main code before getting around to checking the button status. I found the cure! Interrupts! EngBlaze has a great write up on … Continue reading Slow Button/Switch Reaction

DHT11 Digital Temperature & Humidity Sensor

This was my first sensor. It's a digital temperature and humidity sensor. It uses three pins, two for power and one for data. It worked perfectly...except....the libraries provided by Virtuabotix ($9.99 via Amazon.com) didn't work with the Arduino IDE v1.0. So if fixed it! You can download the library from this post. Remember to place … Continue reading DHT11 Digital Temperature & Humidity Sensor

Code to Control Servo via Potentiometer

This example shows the code to control a servo on digital pin 2 via a potentiometer on analog pin 0. You can change the pins around via the variables in the beginning of the sketch. [php] #include <softwareservo.h> SoftwareServo myservo; // create servo object to control a servo int potpin = 0; // analog pin … Continue reading Code to Control Servo via Potentiometer