Week 11:

INPUT DEVICES :

This week assignment is to build a PCB that connected to an input , and read from it , however after the class immediately I decided to build this PCB and use it for my final project which is fixed wing aircraft , so I will build a transmitter , to help me controls the aircraft , so my whole Idea is building a transmitter that transmit the signals from this board to the other board that I am planning to build in OUTPUT DEVICES WEEK via Bluetooth .

so before I designed my board I drew a sketch to help me identify the components’ that I need to use in my transmitter ,

So the components that I will use are :

ATMEGA328p (microcontroller )
CRYSTAL (20 MHz)
REGULATOR (to regulate the voltage from the battery into 5 V)
AVRISP
5 CAPACITORS (2 for the crystal and 2 for the regulator 1 for the excess V)
LED
FTDI
BATTERY SMD (2x2 pin holder )
BLUETOOTH SMD (1x4 SMT)
SLIDE SWITCH
POTINTIOMETER SMD (2x3 pin holder )
JOYSTICK SMD (2x3 pin holder )
5 RESISTRS (1 for button 1 for led 3 as jumpers)
BUTTON (to reset)

So after identifying the components I started to read some of their datasheet like :
* ATMEGA328p.
* 5V REGULATOR.
* CRYSTAL.
Reading the datasheets helped me to configure the best connections for the components , so I started to do my schematics ,setting the components that I need and connect them.

So after I did my schematics I am ready now to make my Board and connect the traces, I started to connect the traces with 10 mill width using Auto router , but it was not 100 % complete.

So I connected the traces manually , but I had to use 3 jumpers, it was a difficult task but I learnt a lot from it.

Now my board is ready , but I did a final check by using DRC (DESIGN RULE CHECK) , to check the clearance.

Finally I saved the traces and the outline as PNG files , to be able to use fabmodules, and I will be following the same process that I did in week 5, to use fab modules and cut the board using SRM-20.

You can see now in this video the final step of cutting the outlines.

However I was excited to finish this board so I forgot to take a photo of it before I started to solder the components .

This my board after the soldering and I did the continuity check as well , so the board is ready for programming .
## PROGRAMMING:
I did not do much in programming , I just wanted to get an idea about the potentiometer programming , and to make sure that my board is programmable, I kept the real program to the end when I will start to work on my final project , so I will write about it in details in my Final project page.
So all what I did , I copied a code from this tutorial , I did some modification , by adding the pin that I will use , and I tried the mapping as well, for the serial read , to know the value that the POTINTIOMETER will give, however you can see that from my schematics that I connect the TX , RX in a wrong way , but I fixed it by flip the connection in my program .

I did test the program on my board and it work perfectly as you can see in the video below :

PROBLEMS THAT I FACED :

It was not an easy process at the beginning I faced some issues, and the main one was the traces , the width f the traces was 10 mill , but some of them was not clear and the ATMEGA traces was to big to solder , so I had to made it 6 mill , and I did not change the mill bit , I kept it 1/64 as usual and it works , however my major challenge was to solder the ATMEGA properly ,because the ATMEGA legs were to close to each other , I repeat it 5 times to solder it well , but it was a good practice for me .

IT WAS A GREAT TASK TO DO I LEARNT A LOT ABOUT THE ELECTRONICS , AND I INCREASED MY HAND SKILLS IN SOLDERING

You can find all my working files on this ZIP FOLDER.