Week 11 - Output Devices

Learn to add an output device to a microcontroller board you have designed and program it to do something.


Design the Hello Servo board



Designing the schematick circuit in Eagle.

Routering the circuit in Eagle.


We should introduce a modification in the example board given. So I decided to introduce a four pin conector that will allow to conect the input board to another output board in the future (VCC, GND, TX and RX).



Output device board design.


I decided to use the pin PA1 to conect the RX (input) and the PA2 to conect the TX (output) in the ATtiny 44 microcontroller.


ATtiny 45 pins schema.






Programing a Servo

First of all I connected my FabISP via USB to my lapop, the Hello Servo via FTDI cable to another USB and then a communication cable between them.

I found some issues trying to program the board in Windows 8.1 so I decided to do it trough the Linux emulator CygWin 64 and it worked.

In CygDrive I navegated trough my laptop until I got to the hello.servo.44.make fileI wrote:

make -f hello.servo.44.make program-usbtiny

But I can not programmed it...so I try to do it through command line in Windows 8.1 but I can not either.


Hello Servo programming faliure with CygWind an C.


ls (Linux) = dir (Windows)

So I decided to use the Servo board made by Nuria at Fab Lab León that had already the firts servo program charged in it and when I connected the servo motor to the board it properly run.

I tried to program the second servo program in the Servo board made by Nuria with CygWin in my laptop in order to discard that it could be a fabrication problem and it allowed me to charge it properly.




Nuria´s Hello Servo sucssefully programmed.


Although I looked for connection problems in my board it did not worked so I tried three different ways:

05/2/15 - Networking and Communication assignment:

I repeated my Hello Servo board introducing slight changes in the traces.

But it did not allowed me to program it either...

DeployeHand DeployeHand DeployeHand

Milling redesigned Servo board.

Servo board components.

Soldering Servo board.


05/07/15 - Interface and Application Programming assignment:

1 I repeated my Hello Servo board redesigning it with thinner traces.

But it did not allowed me to program it either...


The three attempts of my Servo board design with the four pins connection to communicate.


2 I strictly reproduced Neil´s Hello Servo and I recovered the components from my firs servo board design to discard a component failure.

But it did not allowed me to program it either...



Desoldering components from my first Servo board design to solder them on Neil´s design.


05/16/15 - Applications and Implications:

Every time I try to load the program skips the same connection error message, so I milled again Neil´s and mine Servo design and I ask Nuria for helping me to solder the same recovered components on Neil´s and Fabricio´s boards.

And finally we could program my servo design board!



Fabricio´s Servo Board design sucssefully programmed.

Neil´s Servo Board design sucssefully programmed.


So I decided to load the hello.servo.44 program in Fabricio´s board and the hello.servo.44.2 in Neil´s to undestand the differece between each program.

Now I am ready to complete the next Communication assignment!


- - -


· hello servo fabricio (Eagle schematic)

· hello servo fabricio (Eagle board)

· hello servo (png traces)

· hello servo (png boundary)

· hello.servo.44.make

· hello.servo.44.2.make



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