Fab Academy 2014: Class Archive Fab Central

How To Make (Almost) Anything

by Tiago Figueiredo




Week 13: Networking and Communications




In this week assignment we had to network several boards together in the form of a serial bus. The purpose rests on the intention of making a networking communication between the boards from the computer. The computer will control which board goes ON and OFF at the time we want using Arduino Serial Monitor for the purpose.




The Bridge



After milling the board and solder the components it was time to start programming the board. As always, connection between your FabISP and your board will be required. The first board, the "bridge" board will be the first to have an ID:


  • For each node in our network, we need to modify the "hello.bus.45.c" code. The "bridge" board is also a "node"

  • Each node needs to have a different ID number (1, 2, etc).

  • In the c code, change the line: "define node_id '0'

  • Now save your C file and connect your board to your computer trough the FTDI header to provide power to the board, and using your FabISP, flash the bridge board as node 0:


    sudo make -f hello.bus.make program-usbtiny


    Now, repeat the same process for your other different nodes. In my case, the Output Device board is my other node so as I did with the last board, now I want to define this board ID as 1.


    After programming each node of your bus, it's time to open Arduino and the Serial Monitor to flash each board accordingly to the number you input on the software.


    I cannot understand why, but after defining the board IDs, whenever I input a different number on Arduino's Serial Monitor, both boards flash. I really tried to understand the reason for this to happen, but with no success. After resting a day on this matter, I tried to connect both boards again, but this time the bridge board is not receiving power from the FTDI. Besides that I cannot make them work again on Arduino's Serial Monitor. Here I will leave a video of the failed result:






    Project's Files


    Here you can download the files for this project:


    Schematics and Board Diagram



    Thank you for watching, stay tuned!

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