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  • Week 10 (Output Devices)
  • Week 11 (Machine Building)
  • Week 12 (Molding and Casting)
  • Week 13 (Input Device)
  • Week 14 (Composites)
  • Week 15 (Networking and Communications)
  • Week 16 (Interface and Application Programming)
  • Week 17 (Applications and Implications)
  • Week 18 (Invention, Intellectual Property, and Business Model)
  • Week 19 (Project Development)
• Final Project

WEEK 13 – INPUT DEVICE

Weekly assignment

Add a sensor to a microcontroller board that you have designed and read it

For this week's assignment I made the hello.HC-SR04 board

BOM

• ATtiny45 microcontroller

• 1uF capacitor

• 10K resistor

• 6-pin ISP header

• FTDI header

• 2x2 pin header

Designing the board

As usual I started designing it on Eagle

I only changed the pin header using a 2x2 to connect the sensor (HC-SR04 V1.0)

Programming the board

After soldered and connected the board to my FabISP I started to program. Before to do this I downloaded Neil's C code and .make file adjusting it to my project

When I moved to type the make-program I recieved an error

But I only had to repeat the command and it worked

I didn't set the fuses because this time I didn't use an external clock as I did in my previous boards, but the ATtiny45 internal clock (8MHz)

Programming With Python

Before this week I didn't know what Python was, so I needed to read something about it

My instructor suggested me this tutorial wich was foundamental. And with a big help of my classmate Simone I've been able to get the job done

First thing I downloaded Neil's python file and I made it executable by typing the command in my terminal

But when I moved to launch it I recieved an error...

The command is not found because I typed "./" as a link to the current folder, but in the .py file there wasn't the line wich defines that file as a python

Then I added that line on the top (the first blu line in the document)

Otherwise I could type the command "python dist_sensor.py" without that line and it would work well

But when I repeated the command I recieved another error...

The message ask to install the python-tk package. So I did it

Then I had to find the serial port wich the FTDI was connected...

...because when I tried to launch the python file I recieved a notification that told me that the right command to type includes the serial port

And also another one that asked for superior permission

Finally I was able to launch the python file and then to recieve a visual feedback of the device working

Eagle and programming files here