I designed electric circuit based on a sample and made circuit board using it.
I drew the circuit for the echo hello-world board being added a button and LED. I choiced the EAGLE as a schematic design software because there were many tutorials and it was free.
C:\EAGLE 8.0.2\lbrSelect [Library] menu from the side bar and right click on the [fab.lbr] and select [use].
[File]→[New]→[Project]Right-click on an "Echoboard" in the side bar and select [New] and [Schematic].
Add: Select a necessary component from the window and push the [OK] button.Rotate right click Move:Click a + mark on the component and drag a mouse to move each component. Net:Connect each component or terminal. Label:Label each component or terminal. Name:Name the label. Value:Set a value to the label.
Displey and set a grid [View]→[Grid]→[Display:on] At first, I set a grid pitch to 0.05 inch. But finally,I set it to 0.01 inch because I wanted to adjust the distance of some lines finely. Move:Click a + mark on the component and drag a mouse to move each component. In the case of moving multiple parts at the same time: [Move]→[Group]→[Move]→select components→Right Click→Drag Route:Connect each component or terminal. When I make a mistake, I use a Ripup command. Line:Draw an outline.
Push a layer setting button and Select a necessary layer.
Trace: [Top][Bottom][Pads][Vias][Unrouted] Outline: [Dimension]
Export as "image". Settings was as follow.
I used SRM-20 for milling a circuit board. After shaping the surface, I set a material (FR1) on it with double sided tape.
EndmillsI used the endmills as follow.
I set the tool pass with Fab Modules. I tried several times because it did not work at once.
tool diameter (mm): 0.4mm number of offsets:4 offset overlap (%):50Failed: The area where the line distance was narrow was not cut.
Move the component (6 pin header) . Change the width of line that connected to each other in the first trial. （0.016 inch →0.008 inch）I change the parameter of Fab Modules.
tool diameter (mm): 0.2mm number of offsets:3 offset overlap (%):60Failed: Close line and parts were connected.
The line passing between the pads was close to one of them. So I changed the grid width from 0.01 inch to 0.005 inch and let the line pass through the middle between the pads. I thought it was succeeded. (Actually it was a failure.)
|Resistor 10K ohm||2|
|6-pin programming header||1|
|Resistor 499 ohm||1|
I soldered all components.
After assembly, I checked wheather it was soledred correctly with digital multimeter. When checking the continuity of adjacent terminals of 6 pin header, the alarm sounded. At this time, I noticed that there was a mistake left.I removed the parts with hot air gun and cut the unnecessary line with chizel.(If I had a hand router at that time, I used it.)
In this time, I definitely wanted to make sure that the soldering was done well and there was no short-circuit. So I used AVR ISP mk2 which is a more reliable device than Fab ISP that I made. Fab ISP was done well as shown in week08.