Week 11: Output Devices
I week I learnt about charlieplexing, a multiplexing technique use to manage a matrix of LEDs
with few control pins on the microcontroller. I first made Neil's LED array board and created a paper prototype of
7- segment display
using ATTiny 85 and 14 LEDs. I used David Mellis's Tiny programmer to upload the program onto the chip.
I also tried to make a bug board with two tiny DC motors but it didn't work.
Making Hello array board
This helped me to understand how charlieplexing work.
I used my Hello ISP board to program the hello array board.
I used these steps to upload the program:
Open terminal
Go to the folder where you have saved the .c file and .make file
Type the following code
$ make -f hello.array.44.make
$ make -f hello.array.44.make program-usbtiny
I used my Hello ISP board to program the hello array board.
I used these steps to upload the program:
Open terminal
Go to the folder where you have saved the .c file and .make file
Type the following code
$ make -f hello.array.44.make
$ make -f hello.array.44.make program-usbtiny
Creating a 7 segment display using ATtiny 45
I liked the idea of creating your own 7 segment display and programming it using ATTiny microcontroller.
I used 4 pins on ATtiny as charlieplexed output.
I used this tutorial.
I made a paper prototype and soldered the components using copper tape.
I numbered the segments from 0 to 6 and marked it on the paper to help me create combination for different numerals.
I used the following combinations
For '0': 0,1,2,3,5,6
For '1': 1,2
For '2': 6,0,1,5,4,3
For '3': 0,1,5,2,3
For '4': 6,5,2 For '5': 6,0,5,2,3
For '6': 6,0,2,5,4,3
For '7': 0,1,2
For '8': 6,0,1,5,4,3,2
For '9': 6,0,1,5,2
The code on the website didn't work. David explained the code and helped me break down the code in the simpler version. I used Tiny Programmer to upload the program onto the ATTiny chip.
Here is the output
I am still working on the final board design.
I used this tutorial.
I made a paper prototype and soldered the components using copper tape.
I numbered the segments from 0 to 6 and marked it on the paper to help me create combination for different numerals.
I used the following combinations
For '0': 0,1,2,3,5,6
For '1': 1,2
For '2': 6,0,1,5,4,3
For '3': 0,1,5,2,3
For '4': 6,5,2 For '5': 6,0,5,2,3
For '6': 6,0,2,5,4,3
For '7': 0,1,2
For '8': 6,0,1,5,4,3,2
For '9': 6,0,1,5,2
The code on the website didn't work. David explained the code and helped me break down the code in the simpler version. I used Tiny Programmer to upload the program onto the ATTiny chip.
Here is the output
I am still working on the final board design.
Designing the Bug Board
This week I also wanted to experiment with designing the circuit board in different shapes. I want to make bugs that can crawl.
So I tried to draw a board with DC motors. After Making the board I realized that I was looking at the wrong reference sheet for DC motors.
Motors cannot be attached directly to the microcontroller. You need a transistor.
Here is my board. It was fun and time consuming. I will redo this.
Here is my board. It was fun and time consuming. I will redo this.