Post on 09-May-2015
description
ARDUINO
Open Source
Open Hardware
A simple computer which can gather input from reality and interface outputs with the
environment however you instruct it to
http://arduinothedocumentary.org/
Fundamentals Of Arduino
• Write sketches or modify existing ones to suit your needs
• Wire an electrics circuit• Upload the sketches to the Arduino (via
USB connection) and connect the electrics circuit to the arduino, by joining wires to the sockets on the Arduino board
• 5V & GND : sources of power• Inputs and Outputs• Data transmission
Nomenclature
• On board sockets = Pins• Any numbered pin = input
or output• TX = transmitting
RX = receiving• Arduino AKA microcontroller
What is Arduino?
fig (i)
Sources of Power
The arduino has three GND pins and one 5V out The pins can be used to create a 5v DC circuit, _sufficient to illuminate an LED (fig ii, above) A resistor is necessary to ensure the current does not _burn out the LED
fig (ii)
Breadboard: An Arduinos Companion
The breadboard holds components external to Arduino Each socket on a breadboard connects to a conductive _horizontal or vertical strip
Electrical Circuits
The yellow trail indicates the positive pole of this circuit The green trail indicates the common or negative pole When both trails are linked by the LED, the circuit is _completed
fig (iii)
The Logic of Switches
The LED does not complete the circuit this time – _instead a button links the positive and negative poles _of the circuit A button can be pressed (ON) or not pressed (OFF) Depending on the buttons state (ON/OFF) the circuit is _complete or open
fig (iv)
Digital Pin :: input & output Digital means two possible
states HIGH/LOW = ON/OFF
5v – 0v = ON/OFF Programmed code tells the
arduino whether each pin is HIGH/LOW (aka on/off)
(The arduino assumes a pin to be off until told otherwise)
Input & Output: Digital
fig (v)
Digital Switches
This circuit is the same as fig (ii) This time the HIGH signal from digital pin 13 _supplies the 5v positive pole to the circuit
fig (vi)
Digital pins detect whether a circuit is in an ON or OFF state
When arduino measures voltage in a circuit it will register0 – 2.5v equal to LOW2.5v – 5v equal to HIGH
LOW == OFFHIGH == ON
Digital Sensors
fig (vii)
* Not just HIGH/LOW* Instead 0 – 5v is a wider
spectrum of values to measure
0 – 5v = 0 – 1023 in Arduino
Input & Output: Analog
* Analog Pin(s) :: input only* Analog is different to digital
*Analog equals continuous*Digital equals discreet
fig (viii)
Multimeter: Good Electronics Practice
• Multimeter reads resistance, voltage and ampage
• Multimeter is a big help to making sure you’re electronic circuit works the way it should:
• a circuit should always work the way you expect it before writing/amending arduino code
Other Variable Resistors
• LDR = Light Dependant Resistor
• Thermistor= heat dependant resistor
• GSR = Galvanic Skin Response
• FSR= Force sensitive resistor
Galvanic Skin Response
Thermistor
Serial Port Communication
Serial Port is how the Arduino Communicates with other Digital Devices (E.G. the computer or a digital SD card)
All computer tethered communications go via the serial port which arduino is connected to
Serial Port data can be accessed by software other than Arduino programming software (most readily via Processing)
Arduino can save data to SD cards using the TX and RX facilities (advanced feature)