Assignement
add an output device to a microcontroller board you’ve designed and program it to do something
What i am going to do
I want to make a speedometer using LED Arrays using a Optical Encoders.
Output Devices
The output is what results from an electrical circuit.
Any of the following components may be used as outputs:
LED
Piezo buzzer
Servo motor
Stepper motor
LCD Display
LED
Light Emiting Diode (LED) it is the basic example of output device in electronics projects Blinking LED is called “Hello World” it is a Diode it works only in forward biase and it availble in diffrent colors and sizes.
Piezo Buzzer
Piezo buzzer is an electronic device commonly used to produce sound ,Piezo buzzer is based on the inverse principle of piezo electricity discovered in 1880 by Jacques and Pierre Curie ,It is the phenomena of generating electricity when mechanical pressure is applied to certain materials and the vice versa is also true. Such materials are called piezo electric materials
Servo Motor
A servomotor is a rotary actuator or linear actuator that allows for precise control of angular or linear position, velocity and acceleration. It consists of a suitable motor coupled to a sensor for position feedback
Stepper Motor
A stepper motor is a brushless, synchronous electric motor that converts digital pulses into mechanical shaft rotations. Each rotation of a stepper motor is divided into a set number of steps, sometimes as many as 200 steps. The stepper motor must be sent a separate pulse for each step.
LCD display
LCD (Liquid Crystal Display) screen is an electronic display module and find a wide range of applications. A 16x2 LCD display is very basic module and is very commonly used in various devices and circuits.
Charlieplexing
I want to display Motor RPM using a LED array for that iam using Charlieplexing Technique. a Charlieplexing is a technique for driving Multiplexed LEDs in which relatively few I/O pins Microcontrollers. ATtiny45 have only 6 IO pins if we need to control 6 LEDS normally we want 6 PINS , But if you are using Charlieplexing you can control (n2 − n) LEDs. where ‘n’ is no of available pins .
Charlieplexing Chart:
LED Array Circuit Diagram
I designed a 6 LED using 3 Pins Circuit in Eagle , in Eagle Layout You can see the LED Array arrangements . Charlieplexing ATtiny45: Eagle Layout:
Board
I arranged PCB Board in a circular shape for displaying LEDs in the form of a speedometer.
Eagle Board: Stuffed PCB :
Programming
I used Attiny45 + Arduino , Charlieplex Library available in arduino . That is very easy but you need to understand working of Charlieplexing Circuits .
First I Programmed a simple charlieplexing Running Light .
Code :
Final Video
ATtiny45 Charlieplexing -Output Devices Fab Academy 2016 from Jaseel on Vimeo.