This is a YourDuino Robo1 which is an Arduino-compatible microcomputer board with some updated features.
We will be connecting many different devices to Arduino. On the left we show sensor inputs which bring information about the real world into Arduino. On the right side we show action outputs which Arduino controls to affect things in the real world and communicate to humans. In the center, is the software which will make the decisions which create the intelligence and behavior of a microcomputer system. Now we’ll look at the actual connectors where all these external devices attach.
Here’s a more detailed look at YourDuino Robo1. It can be used to make many different types of intelligent devices such as: robots, home control systems, artistic displays, etc. It is easier to use than the original Arduino because it has added connectors for plugging in a wide variety of input and output devices. Next we will look at ways of connecting external devices to Arduino.
This schematic diagram shows the way we think about the electrical reality of Arduino and the connections to external devices. At the top, we have a red line representing the +5V power for Arduino and other devices. At the bottom, we have a blue line representing the ground connections to Arduino and devices. All external devices must be connected in some way between the 5V rail and the ground rail. In this example, on the Left, an Arduino Input pin is connected to a pulldown resistor to ground (Low) and a push button switch to 5V (High). The pulldown resistor brings the Input to Ground (Low) until the switch is pushed which connects the Input to 5V (High). Software in the Arduino can notice that the Input signal has changed from Low to High and it can make a decision to take some action. In this example the software can switch the Output connection from Ground to High, which will turn on the LED. Next we will look at how to physically connect devices to Arduino.
Here is an Arduino connected to a Breadboard which we will later use to plug in and connect many different devices. Breadboard details later. The Red wire connects connects Arduino 5V to the Red 5V rail running across the top of the Breadboard. The blue wire connects Arduino Ground to the blue Ground rail. Next let’s look in detail at the Arduino connections and the details of the Breadboard.
Here’s a closer look at the upper section of 3-Pin digital I/O connectors. Arduino digital I/O pins can be used to connect to various different Digital Input devices such as: Push Buttons, Tilt Switches, Light Sensors, Motion Detectors, etc. The same pins may also be used to connect to various different Output Devices such as: LEDs, Buzzers, Lasers, Relays, etc. Each signal pin is in a 3-Pin group which includes Ground and +5V which may be connected easily to devices that need those connections.
This lower section of 3-Pin connections is for Arduino Analog I/O Pins which can measure voltages in the range of Ground to +5 Volts. These may be devices which return a value such as: Light level, Temperature, Pressure, Soil Moisture, etc. instead of simply HIGH or LOW. These pins may also be used as regular Digital I/O pins.
A breadboard is a reusable construction base for creating new electronics projects. Wires and electronic components with pins, such as Resistors, LEDs, Buzzers, etc. can be plugged into the holes in the Breadboard to create needed circuits. The internal connections are shown on the following slide.
This shows the back of a Breadboard with the usual insulating backing removed. Groups of holes in the Breadboard align with metal strips so that multiple components may be connected together by plugging them into the same strip. The horizontal strips which are marked Red and Blue are usually used for +5V and Ground. The Vertical strips which appear silver here, are used as common connection points for the components that make up a circuit. The term breadboard comes from early electronics experimenters who built vacuum tube radios on the wooden boards found in most kitchens in 1920.
This shows a typical breadboard. You can see the long Red and Blue columns which connect together and are marked + and – . The short rows of 5 holes each are independent tie points where 2 or more components connect together.
These are some of the connection devices used with Arduino, breadboards, etc. The ribbon cable has many wires that are lightly stuck together and can be easily striped off as individual wires or groups of wires to connect to various devices. The wires ends have female sockets that can plus onto the 3-Pin connectors on the Yourduinoor other devices that have male pins. When a wire needs to have a pin end such as those shown on the far left, a double ended pin like those shown on the pin strip on the right, is snipped off and plugged into the wire end. These male ends also plug into the breadboard holes.
Look again at this example diagram. Next we will show how to implement the Input circuit on the Left on a Breadboard.
This shows a Push button switch and Pulldown resistor connected between the +5V rail and the Ground rail. The connection point between the switch and resistor is connected to an Arduino Input pin.
This shows the Output circuit which you saw on the Right side of the diagram. Here an LED and resistor are connected in series to the Ground rail and the LED is connected to an Arduino Output pin. Software such as the “Blink” sketch can switch the Output pin back and forth from LOW to HIGH, (Ground to +5V) and blink the LED. Now let’s look at some LEDs and how they are connected.
LEDs are Light Emitting Diodes. The longer leg is positive and the shorter leg is negative. The LED pins can plug into a breadboard, the end of a wire connector, or be soldered to some more complex circuit.
This shows the internal construction of a typical LED. The small semiconductor die (chip) puts out light from its edges and so it is placed in a tiny reflective mirror to direct the light out of the end of the LED.
Electronic circuits often have sections in which electrical current needs to be controlled. Examples are: driving LEDs and pulling Input pins to +5V or Ground. Resistors are components that have a well-controlled electrical resistance. Resistance values often cover a wide range from a few Ohms to millions of Ohms. Typical values might be 220 Ohms to control the current through an LED, or 10,000 Ohms to lightly pull a digital input up to +5V or down to Ground. The photo above shows how resistors are marked with a series of color coded bands.
The color codes on a resistor are used to show its resistance value. Resistors are made with different power handling ability. Physically smaller resistors have a lower power rating.
Resistors are used to control the current in a circuit. It has electrical resistance created by the material inside it which is usually made up of carbon. The carbon mixture can be changed to produce a wide range of resistances.
These push button switches have 2 connections which do not conduct electricity until the button is pressed and the circuit is completed. These particular buttons have 4 physical pins so that they will fit securely in a circuit board or breadboard.
The color bands on this resistor are brown-black-black-red, which means 1-0-0-2. However, the last number is a multiplier which tells how many zeros to add to the number. So this is 1-0-0 and 2 more zeros, or 10,000 Ohms. This resistor is typically used with Push Button switches.
Here is the type of Photo Resistor used in typical Arduino kitsas a light sensor.This particular photo resistor has a resistance of 10,000 Ohms when illuminated with a light intensity of 1 lux.
A photoresistor is made from a special material called Cadmium Sulphide, which has the property of decreasing its electrical resistance when light falls on it.To include a lot of contact area in a small space, it is shaped like interlocking fingers.
These 2 devices make sound from electrical signals. They are different in that the Buzzer makes a continuous sound when a voltage (usually 5V) is applied. The Beeper is a simpler device which moves its speaker in response to an applied voltage. Applying a voltage once will make a single click. However, Arduino can send a series of pulses to a Beeper and make many different sounds.
A Potentiometer is a mechanical device whose resistance changes with the physical rotation of an input shaft. (Which often has a knob attached to it for people to turn, such as the volume control on your stereo) A Potentiometer is a resistor which is made in a circular shape.
Rotating the shaft connects the wiper to the resistor in different places along its circumference.
This is an electronic thermometer which has high accuracy over a wide range (accurate to ±0.5°C over the range of -10°C to +85°C). You can locate these thermometer chips up to 100M away from your Arduino. Shorter cables can be just 2 wires. Digital signals are sent to and from the chip by Arduino to control it and read the temperature.
A relay is a switch. The switch is flipped by an electromagnet that is controlled by the Arduino. The switch is electrically isolated from Arduino and can control large amounts of power to lights, motors, pumps, etc. The photo above shows 2 relays, (the blue boxes) mounted on a printed circuit board that makes connecting easy.
Servos are small box-shaped electro-mechanical devices that contain a DC motor, electronics to control the motor from a signal, a gear system to produce slow/strong output to a shaft, and a position feedback potentiometer. There are a variety of sizes and weights, of similar construction. They are widely used in Model cars and airplanes, and can cost as little as $3.50
8 Servos and some plastic parts make up this Quadruped Robot. Add an Arduino to control the Robot’s walking, sensors to control its activities in it’s environment, batteries for power and other options you might think up.
Arduino 101 powerpt
Welcome to Arduino 101By Terry King and Mary Alice Osborne at http://YourDuino.com
The parts described in this presentation are from the YourDuino Basic Starter Set