Week 9
Input
Keeping going with the electronics devices. I need to create a new board and programming to react to an input signal.
I decided to work with an Infrared sensor because it is the one that I will use on the seat of my final project.
Before start, I need to think how I can fit the infrared in the chair, pass the cable through and connect to the board. However, I wanted to hide as much as I can the sensor inside the pieces of the chair.
After that, I worked on the design of the board. The first ideas are to connect this input to another board that have to switch on a lamp and start a count down. So, what I add to the board:
I used EAGLE to draw the schematic part of the board. I really do not understand why EAGLE draws a very clear schematics (.sch)and become a mess lines of traces (.brd) Anyway, it is part of the process. The elements of this board are:
- 1x LED, to check is the board respond.
- 1x capacitor.
- 1x resistor 499 ohm.
- 1x ATTINY1614 fits perfectly and gives enough pins to connect and work with.
- 1x button.
- 1x regulator 5v.r
- 1x power supply (battery).
- 1x 6 PINS FTDI, to connect the bluetooth slave.
- 1x 2 PINS, to program.
- 1x 2x3 header, to connect the infrarred sensor.
Once it milled, I welded and after something was wrong, I could not program it. When I was drawing the sketch of the board the FTDI was rotated to fit the lines and when the board was connected to the computer burnt the chip. It was a good lesson. Never again.
Until I got the board, I check the code with an Arduino Kit:
Starting again the process with a right trace. I would like to stop a little to show all the option that you will have in Arduino when you use the microprocessor Attiny 1416.
After that, you are ready to write the code. This one is a simple one for the moment, it was just to check it.
I checked if it is working.
I could not find the picture exactly to show the pins name in Arduino and Attiny1614 but this one fit for me.
The sensor chosen is the infrared sensor with a power from 3v to 5v because it fit properly with the final project. His function is to read the obstacle, that with be when a person is sitting on the chair and send the message to the light connected by bluetooth.
You can know more about the communication between them on week 14
On the next picture, like a part of the group assignment, you can see how to measure the input with the oscilloscope.
