Wheek 14: Networking and Communications

Networking Hello Serial Buss

This week I used the hello world board example to connect several boards together
on a network using the serial bus protocol. The bridge is connected to a computer with FTDI.

Fig 1. FTDI to comunicate the boards to the computer.

All the designs of the boards were once again made using the EAGLE software. All the boards have one led to indicate that tey’re being energized.

Fig 2. The brigde schematic on EAGLE software.

Fig 3. The brigde board on EAGLE software.

Fig 4. The node schematic on EAGLE software.

Fig 5. The node board on EAGLE.
The bridge and nodes will have an attiny45 embedded.
The datasheet shows on this link:

Fig 6.The boards made with modela mdx 540 by Roland.

Fig 7. The pictue shows the soldering of the Attiny 45.

Fig 8. The temperatue on the air from the solder gun was 350C.

Fig 9. The final soldered Attiny 45.

Fig 10. Two nodes finished.
The firs step was to burn the boolader on the respective boards: one brigde and two nodes.

Fig 11. Done burning bootloader.
Get the board files and code:

The Link code with Neil’s code:

I made two nodes and one brigde. I modified the “c” code; for example on the brigde de id number was “0” (# define node_id “0”) and the nodes “1” (# define node_id “1”) and “2” (# define node_id “2”).

Fig 12. Change on # define node_id “1”.

Fig 13. Change on # define node_id “2”.

Fig 14. The tree boards on the picture are connected via RS-232 port. For this assigment I use two prograsm to received the data via usb FTDI. For the first program I used Labview. I made a routine that make changes on the delay and the LED on the red changed the frecuency.

Fig 15. FTDI connect with the program. In this case: Labview the serial port Com 11.

This video shows the the led on the red RS-232, change the frecuency and regulated the intency of leds.
Right mouse button to play video
For the second example, I used the Arduino Ide monitor, when I write on the panel the number for example 2 and send, the led blinks twice.

Fig 16. The serial monitor on the arduino Ide. In order to get the led blinking we have to press the ID button of each board on the PC (1 or 2 for the nodes). In this example I was actived the node 1 through the monitor serial.

This video shows the blink on the node 1.
Right mouse button to play video

  • Download files here:
    node board
    node Schematic
    bridge board
    bridge Schematic
    Labview program.