{ Fab Academy 2015 : Koichi Shiraishi }

{ Home } { Final project } { Class } { Fab Academy }

- Week 13: Networking and Communications -

Weekly Assignment

• design and build a wired &/or wireless network connecting at least two processors

1: Engraving boards

I used the laser again to make the boards. I wrote How to generate a circuit board by laser. You can use “my site (Week 10)” as reference.

It was easy and smoothly by past parameter.

2: Soldering

I need to make few same boards in this week, therefore I decided to use the cream solder. But I do not have reflow oven. Consequently, I utilized a “Hot plate” which is used in cooking. It is very cheep one(about ¥2,400).

MAKING MASKS

Masking data is generated by eagle. Generating method is explained in this site(in Japanese).

The mask usually is made by vinyl cutter, however I think using laser is better way for delicate pattern. Consequently, I tested a few materials by laser.

1)synthetic paper

I used the “YUPO(???mm).” I tried several Parameters again to again. However it was not finished well. Principal ingredient of “yupo” is Polypropilene. It has high coefficients of thermal contraction. Consequently, I changed a material.

2)cotton paper

I tested the cotton paper(t???mm). It was finished better than a “yupo.” I decided to use this.

Parameters: 600dpi

Processing	Laser type	Power	Speed	Frequency	Path
Pattern cutting	C)2 laser(60W)	10%	1%	6000Hz	3 times
Outline cutting	CO2 laser(60W)	12%	1%	1000Hz	1 time

SQUEEGEEING

I used the video below as reference.

How to make a MOTIONER - 01 from YCAM InterLab on Vimeo.

1. Spray a spray adhesive to back of the mask for fixing.
2. Take slight solder from the bottle.
3. Squeegeed carefully. Fill The mask hole by cream solder.
4. Replace the mask slowly
5. Put the parts. Be care orientation of the parts.

HEATING

I used the diagrams below as reference.

Reflow soldering

I did not have a thermocouple. therefore I adopted as a simplified method in this case, I measured the time.

I checked short circuit around a IC.

Failure case

The pins melted on the Hot plate. Consequently, I soldered the pins by a iron after a reflow.

3: Burning the program

I downloaded the "hello.bus.45.c" and "makefile" code from here.

I used this site as a reference.

I need to change the line below in the hello.bus.45.c code. In my case, I defined the bridge as '0', one node as '1', and another node as '2'.

				
					#define node_id '0' 
				
			

I used “AVR ISP” to burn the code.

I connected the FTDI header to the bridge boards, and made the serial connection between the boards with a 4-pin serial cable. After then, I connected ISP to each circuit. I burned the code which was saved each address.

terminal

Move to "hello.bus.45.c" and "makefile" directory. And Type below.

				
					sudo make -f hello.bus.45.make program-avrisp2
				
			

Testing

After burning the code, I tested network communication.

1. Open a Arduino IDE
2. Open the serial monitor from the "Tools" menu > serial monitor
3. Make sure the baud rate is set to 9600.
4. Enter number of a note (pick a number) into serial monitor - press the "enter" key or the "send" button on the serial monitor.

results