Electronics design

.

---

The weekly assignment focuses on modifying and inserting a button, a LED and a current-limiting resistor on a circuit board (starting board: echo hello-world board) using an electronics design software (in this case Eagle). I've learned to use Eagle, modify a schematic and a board, understand the functionality of the processor pins and I've improved my soldering techniques (surface mount) and my knowledge of component function.

---

REDRAWING THE ECHO HELLO-WORLD BOARD. A comparison between the orginal (right side) and the brand new (left side) board is showed in the following figure. The existing component have been moved (i.e. FTDI connection) and: new traces have been drawed, new component have been inported. (highlighted by the blue pen).

After a few trial test regarding the exporting options and the output png size (please remember to use an elevated number of DPI) have been designed. Tools 1/32 and 1/64 have been used in the Roland Modela SRM-20 respectively to cut the external edge of the board (right side) and the traces (left side).

As introduced before the milling has been performed using the Roland Modela SRM-20. Fab modules have been used in order to "transform" the png files into the RML file needed from the machine.

Completed the milling and fter the research of all the components, I start soldering (at home, during the night). The BOM (bill of materials) is composed of: - 2 Resistor 10 K - 1 Red Led 1.8 V - 1 Resistor 180 Ohm - Attiny 44 microcontroller - 1 Capacitor Uf - 1 Cer Resonator 20 MHz - Black Button Tactile Switch - Isp - FTDI

I experienced some problem, due to the very small pieces. Using the desoldering wire has been a constant during my work.

After approximately an hour, the edited board was finished.

As it can be stated from the previous picture, I forget the six pin header for the connection with the FabISP. After the weekly journey to the Fab Lab Frosinone I solder the last part and the board is now ready to be programmed. Go directly to page for programming details.

Download area

---

The following files are downloadable:

Type of file	Description	Link (Type of file)
Echo hello-world board (edge cut)	Image file	(PNG)
Echo hello-world board (traces)	Image file	(PNG)
Eagle file	Schematic	(sch)
Eagle file	Board	(brd)