GENERAL OBJETIVE:
Electronics Design
Redraw the echo hello-world board,
- add (at least) a button and LED (with current-limiting resistor)
- check the design rules, and make it
- extra credit: simulate its operation
- extra credit: measure its operation
The objective of this assignment is to design an electronic tablet based on the hello.44.board plate, adding an input and an output. To achieve complete the assignment satisfactorily, the following steps are performed:
1. Installation of Eagle PCB and own libraries FabAcademy
2. Creating schematic image from hello.ftdi.44.png
3. Creating diagram card from schematic generated in Eagle PCB
4. Creating plate (card) from FabModules
5. Soldier plate components
For this exercise Eagle PCB software 7.5 was chosen because it is free to create smaller plates 100 x 80 mm and with only 2 layers of copper.
Another software was also used Proteus 7 and Multisim 11; however, the latter in that version has no AVR microcontrollers in their libraries; therefore it was only used for simulations of simple circuits.
Installing Eagle PCB and own libraries FabAcademy
First, download the software, this can be downloaded from the following link to download Eagle PCB: http://www.cadsoftusa.com/download-eagle/
Download Eagle library specific PCB with components commonly used in the FabAcademy here: http://archive.fabacademy.org/archives/2016/doc/electronics/fab.lbr
Once downloaded and installed the Eagle PCB fab.lbr library, the only thing you should do is search the C: \ EAGLE-7.5.0 \ lbr (for Windows 64-bit) copy the file and paste fab.lbr in that folder , and they have added components library which already just look to create the schematic.
Creating schematic image from hello.ftdi.44.png
To make schematic based on the class and the components seen go linking connections image with symbols of schematic creating a diagram follows, to facilitate connections symbols GND and VCC are used at different times for represent that will be connected to each other and not have so many connections that confuse the diagram.
Figure 1 Schematic
Creating the board diagram generated from the schematic in Eagle PCB
Once the schematic created in Eagle PCB has a function to switch to the schematic editing window and to start to create it, the first thing to be done is to accommodate the components within the workspace (gray area); and after this you can use the tool to generate self-generation autorouter or automatically tracks, here you can do various tests. On a personal experience it is not recommended because the generator if it fails to accommodate the tracks makes attempts by changing the thickness of the tracks, this can be avoided in the options, but often fails to generate all tracks if you want to do with a plate of one side was the case studied.
So the stroke of the tracks was manually following the links indicating the same software.
Figure 2 Check 1 with autorouter
Figure 3 Check 2 with autorouter
Creating Board from FabModules
Once you have the board layout in Eagle PCB, you should only leave activated the top layer (layer 1) which is where the tracks to be machined and go to the file menu, then export as image here you must choose to be monochromatic, single window, where be saved and quality (600 dpi recommended).
Figure 4 Traces Board
Once you have the tracks, you must generate the cut file, this is done by turning off the top layer and selecting the dimension layer (layer 21) and the same procedure is performed to export the image in PNG format.
Figure 5 Traces, dimension and components Board
Image fabmodules is entered and routes cut are generated and sent to scheming, once completed tracks the same procedure is performed with the external box that will serve to cut the plate for engraving to use a strawberry or vertical cutter 1/64 "while for cutting this is done with a vertical milling cutter or 1/32".
Figure 6 FabModules
Soldier components
Once the plate being machined, slightly sanding to remove excess burrs or chips and thus facilitate the welding process. Reaching a final result as shown, use was made of a wire here this because you forgot to create a track connection to power the microcontroller and the filter card.
Figure 8 PCB Circuit Electronic Design
>
Figure 7 circuit create in modela Roland MDX 20
Figure 9 Final Board