Week 14
Interface and Application Programming
Software: Arduino(1.0.6), Processing(2.2.1)
This week I made an application program for the mic I made on week 10.
At first, I had problems with my mic board. Sometimes it worked, but most of the time I couldn't read it. For example, when I ran Neils python program, I got this error message.
python hello.mic.45.py /dev/tty.usbserial-FTGCKCJC
Traceback (most recent call last):
File "hello.mic.45.py", line 71, in <module>
ser = serial.Serial(port,9600)
File "/Library/Python/2.7/site-packages/serial/serialutil.py", line 282, in __init__
self.open()
File "/Library/Python/2.7/site-packages/serial/serialposix.py", line 289, in open
self.fd = os.open(self.portstr, os.O_RDWR|os.O_NOCTTY|os.O_NONBLOCK)
OSError: [Errno 16] Resource busy: ‘/dev/tty.usbserial-FTGCKCJC'
Even though I was not using the board with any other program, the message told me it was busy?? In addition to that my computer would abruptly shut down every time I disconnect the board’s FTDI cable :(
In terminal, I tried using fuser to list the ports that were used but nothing appeared. I couldn’t unmount the device using umount either. But eventually I was able to solve this problem by simply Burning the Bootloader in Arduino, and finally I could use my board.
For programming my board I used AnalogReadSerial which is an example code in Arduino. Since the Attinys (except for the ATtinyx313) don't have built-in support for serial communication, in stead of using the standard Serial I used the SoftwareSerial Library which allows serial communication on digital pins. I printlned the signal and viewed it using the Serial Monitor. (Once I was done checking the values I changed println to print)
I made the application using Processing. I had a hard time reading the signal, but adding a delay in the arduino program made a huge difference. I smoothed out the data by calculating its average and re-maped the value using map(). The line shows the value from the mic and the circle expands whenever noise is detected. I also added PrintWriter to save the data in a CSV file (which will be saved in the data folder).
