Week15 - networking and communications //////

Assignment:
* Design and build a wired &/or wireless network connecting at least two processors.





For this week I chose to do the asynchronous serial communication board.


MAKING THE BOARDS

I designed the boards in eagle looking the connections from Neal's boards:

Bridge:


Node:



BRIDGE:

* SCHEMATICS:




List of components that I used:

1X FTDI header: powers the board and allows board to talk to computer
Inventory: CONN HEADER 36POS .100 R-A SMD (S1143E-36-ND)
Fab library symbol: FTDI-SMD-HEADER

1X Resistor (value 10k)
Inventory: RES 10.0K OHM 1-4W 1% 1206 SMD (311-10.0KFRCT-ND)
Fab library symbol: RES-US1206FAB

1X 6-pin programming header: for programming the board
Inventory: 649-95278-101A06LF
Fab library symbol: AVRISPSMD

1X Microcontroller: attiny45. Once the microcontroller is programmed, the program stored in non-volatile memory. This means that it will remember the program.

Inventory: ATTINY45V-10SU-ND
Fab library symbol: ATTINY45SI

1X CAP 1uF
Inventory: CAP CERAMIC .1UF 250V X7R 1206-
Fab library symbol: CAP-US1206FAB

1 X 2X2 PIN HEADER SMD

1 X LED 1206 smd

1 X 1k RESISTOR RES-US1206FAB

* TRACES/OUTLINE:




NODE:

* SCHEMATICS:




List of components that I used:

1X Resistor (value 10k)
Inventory: RES 10.0K OHM 1-4W 1% 1206 SMD (311-10.0KFRCT-ND)
Fab library symbol: RES-US1206FAB

1X 6-pin programming header: for programming the board
Inventory: 649-95278-101A06LF
Fab library symbol: AVRISPSMD

1X Microcontroller: attiny45. Once the microcontroller is programmed, the program stored in non-volatile memory. This means that it will remember the program.

Inventory: ATTINY45V-10SU-ND
Fab library symbol: ATTINY45SI

1X CAP 1uF
Inventory: CAP CERAMIC .1UF 250V X7R 1206-
Fab library symbol: CAP-US1206FAB

1 X 2X2 PIN HEADER SMD

1 X LED 1206 smd

1 X 1k RESISTOR RES-US1206FAB



* TRACES/OUTLINE:




MILLING AND SOLDERING THE BOARD

For milling the bridge I used the Roland SRM-20 and folowed the steps from Week4 for doing the rml files.





For milling the node I used the Roland SRM-20 also, but we were reusing a broken mill, so we changed the values of the speed to 40mm/s and the number of offsets to 6.






It mills very quickly but some traces were not so good, therefore the soldering was not easy.




PROGRAMMING THE BOARD

At first I ran the make file and it gave me an error (error 1), it wasn't able to find the usb device connected. Therefore I checked all the connections and I found a bad connection in the FabISP :)

After fixing the FabISP, I first connected it with the bridge to program it, so I ran the make file again: sudo make -f hello.bus.45.make program-usbtiny.



Connections:



For the bridge i left #define node_id '0' in the c file, and for the node 1 we have to change it to #define node_id '1', saved and ran the make file, if you have another node would be #define node_id '2', but i didn't have the time to do another one.



Connections:



Programmed!





Once the boards were programmed, I connected them with a GND-VCC-TX-RX cable and powered through the FTDI cable. After that opened the Arduino serial port and typed 0 (bridge) and 1(node) to check the communication between the boards: the board whose identity corresponds to the number typed will flash a second time and send a message to the serial port.





hello-asynchronous from carovignoli on Vimeo



Download file





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