Tuesday, May 14, 2013

Fab Academy: Input Devices

For the Fabacademy inputs assignment I decided to make a phototransistor board and a thermistor board, thus being able to sense light and temperature. I milled both boards using the 2 profile method described in the electronics production assignment here. I used the standard .png layouts given in the lecture notes here, both of which milled successfully. I then stuffed both boards simultaneously, which saved a good amount of time - definitely getting quicker at boards. Here is the phototransistor board:

And here is the thermistor board:

Light Sensor Board

I started with the phototransistor board, programming it from the C code given. At first I got some communication errors with the board, and found some continuity problems, which were easily solved with a little solder braid.

At first I couldn't get the Python code to detect the serial port, but that was easily solved using the advice in the Providence tutorial here- simply a case of finding the right name for the serial port using ls /dev/tty.usb* in the Terminal and appending it to the Python command, eg: python hello.light.45.py /dev/tty.usbserial-FTF53NJC.

Having done that, I had a working light sensor, here the computer output shown with the sensor in shadow:

and here in sunlight:

Temperature Sensor board

I used the exact same method on the temperature board and got good results without any problems. Here is the computer output at ambient temperature:

and here shown after breathing on the thermistor:

No comments: