assignment 15

networking and communications

15nd week

The aim for this week is design, mill and program a network between at least two processors.

At the beggining, i was wondering about creating a wireless network, but we didn´t had all the components at our lab, and without heat bomb is almost impossible to solder the bluetooth/wifi chips that we had.

So, the basic BUS protocol with two wires (tx/rx).


As for my final project I need to control a few bipolar stepper motors´speed with potentiometers, I can communicate the "control" board with the "actuactors" one. For this initial test, with one is enough

Bridge + potentiometer

I re-designed my Hello potentiometer board from input devices week, moving the input pin to have the tx/rx pins free to allow serial communication. According to the datasheet, at the Attiny45 those pins corresponds with PB3 and PB4

Stepper Motor

For the "slave", I redesigned the New Bipolar Stepper board that I made at the second/third chance at the output devices week, moving the connections to have the TX/RX Pins free.

I´ve used this board to solve Output devices assignment at the end.


As I saw in previous assignments, for Serial Communication is needed the SoftwareSerial library in Arduino IDE.

The "master" should write over Serial the desired value, and the "slave" reads it.

I had to remember the Attiny´s pinout correspondance with Arduino to identify the RX/TX pins. RX must be connected with TX in the other board and TX to RX as well.

My potentiometer board was giving me a short noisy range of values. Then, for test if the Serial Communication is working properly, I hand-shacked the values to send over serial between the two boards.

Serial test stepper from Marta Verde on Vimeo.

Input Pot board

Input Pot schematic

Input pot traces

Input pot outline


Output Motor board

Output Motor schematic

Output traces

Output outline


Send Arduino

Receive Arduino


Described your design and fabrication process using words/images/screenshots


Explained the programming process/es you used


Outlined problems and how you fixed them


Included original design files and code