Week 11: Input device

Light sensor: board fabrication

The board is here from Neil page

The traces are taken directly from Neil page Having already milled the hello board, I took this opportunity to learn from Vincent Dupuis how to etch boards (although it is strongly disapproved by Neil). The board is then prepared with soldering paste. I use a stencil (rhodoid 0.1mm - laser cutted) to spread the paste. All component (but plastic connectors) are placed, and the board is reflow soldered. The connectors are finally manually soldered. Here is the final board:

Board programming

The board is connected as follows:

Obviously using avr-gcc installed stand-alone would be elegant. Although the version installed from Fink is working fine up to know, it does not work with the input board for ATtiny45. Our instructor suggested to use the avr-gcc version from Arduino IDE, since it can be kept up to date regarding library, boards and programmers. Then :

PATH=/Applications/Arduino-1.6.6.app/Contents/Java/hardware/tools/avr/bin/:$PATH

But, it is also mandatory to use the right config file. Modify the Makefile to use -C /Applications/Arduino-1.6.6.app/Contents/Java/hardware/tools/avr/etc/avrdude.conf

Then everything works fine !

Board testing

Here is the execution test. Initially, the figure stayed at zero, even when masking the sensor with the finger, whatever I did...

After numerous trials, after double checking all soldering, reprogramming and so on, I found the solution !

Take a few seconds to look at the previous picture, and then click "here for the answer, and to see it working.

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