The task this week was to design the Echo Hello-World. With the adding a led and a button to the schematic.
Below we will describe the steps to follow:
Step 1. Download and install the software Eagle
¿What is Eagle?
Eagle is a software that allows us to develop PCB's, autorutear, generate schematics, develop libraries of components or electronic devices, etc. Comes in a free version that can be found at:
Eagle
Step 2. Download the board of the example Echo Hello-World.
Echo Hello-World
Step 3. We downloaded the libraries of the following link:
Libraries
Step 4. We installed the libraries, decompressing the file.
If we're using Windows we must do so at:
\EAGLE-6.5.0\lbr
Note: I am using the 6.5.0 version of Eagle, in its case check what version you are using.
Step 5. We opened Eagle
Basically Eagle allows us to work with two files simultaneously, the schematic and board.
Schematic (.sch) : It is the representation of the circuit. Here we'll find the logical components.
Board (.brd) : Here we'll find electronic components and their connecting routes, distributed for obtain the file that will be used to mill the copper board.
Step 6. Once that we already have some handling of Eagle (see tutorials quoted above), we opened the board that we downloaded in step 2.
We have to note that the list of components that are being used is:
We will be guided of the image of board to create the schematic, taking advantage that the components can be found in the bookshops fab and ng.
Note: Of all the components, only the led diode is the one with polarity, also be careful with the Attiny44 microcontroller and the orientation of his "pines".
Step 7. We created a new schematic in Eagle, according to the list we are looking for each component in the libraries mentioned. We make the relevant connections and finally we add a green led, a resistor of 1k for the led, we add the button and a resistor of 1k for this same. We used pin 5 for the button and pin 10 for the led.
Step 8. We generate the file .brd
This is the most difficult part, because we have to describe the connection paths the components by avoiding crosses and short circuit.
For routes I used the default thickness. Also, normally you should not use routes with acute or right angles because they make the circuit become in antenna. Although this observation should be taken into account only when we use a larger resonator at 20 MHz.