WEEK8

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WEEK ·8·

EMBEDDED PROGRAMMING

INDIVIDUAL ASSIGNMENT

1. Read a microcontroller data sheet. 2. Program your board to do something, with as many different programming languages and programming environments as possible. 3. Optionally, experiment with other architectures

1. DATA SHEET

The first thing I did was to check the Data Sheet which is a complete guide that explains each pin and its type to know what to connect to where. You can download it from this link

I found this image for pin equivalence with an AtMega 328. My LED would be located on the digital pin 11

This graphic shows the equivalences between pins of an AtMega 328

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1. MAKING AND SOLDERING THE PCB

I chose the Fabkit 0.4 version for this assignment. The files are downloaded from the FabAcademy page by clicking here.

It's probably the sixth time I make a PCB so now it's a lot easier.

It is the first time that I use the Modela machine to make perforations. They are made in the option of "cut out board" and it takes very little time.

Like cutting the frame from the PCB.

This is the final result. As you can see there are many tracks together and this is a problem. I Checked the Eagle file and re-mill the PCB but it went back like this.

So I decided to change to FabKit 0.2 but I made a mistake choosing the file, I made another PCB so I had to start over again.

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2. FABKIT 2.0

Finally found the files of FabKit 0.2. Find them by clicking here.

I used the Modela machine and the FabModules (that is installed in all the machines of the FabLab Esan)

First I made mill traces using the 1/64 bit. This time I did not break any drill bit!

Making mill traces takes longer by setting 0.1 in error (pixels) but the accuracy of the job is greater.

Then I cut out the perforations

As the image was with the inverted colors, the machine began to cut the circles that it had to perforate. I missed another board..

This is how the drill file should look.

I had to invert the image using Paint. Always check that what you want to cut this in color black.

And that's how the file to cut the edge should look like.

Cutting the edge takes less than 5 minutes

Finally, this is how the FabKit 0.2 board ends

This is the Eagle file that tells us which components we will weld.

Welding the AtMega was a challenge. At some point the welding joined two legs and for wanting to separate them with a tool that sucks the tin it end up sucking a leg and a piece of track, I had to make a new board all over again.

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3. BOOTLOADER

The first thing to do before running a program is to upload the bootloader that will allow you to recognize this board as an Arduino. For this we need an FTDI cable that connects to the computer and cables that connect the pins with the AVG input

Programming Cable 5V FTDI - 3.3V I/O The FTDI cable is a USB to Serial (TTL level) converter which allows for a simple way to connect TTL interface devices to USB. The VCC pins of this FTDI cable are configured to operate at 5V with 3.3V I/O. The other side of the cable is terminated with a 0.1" pitch, 6-pin connector with the following pinout: RTS, RX, TX, 5V, CTS, GND (RTS is the green cable and GND is black).

This is how it will look.

I could not get the Bootloader the first time. But with the help of our FabAcademy instructor we saw that a library had to be installed on the computer.

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4. PROGRAMMING IN ARDUINO IDE

Installing the Arduino IDE program is quite simple, you can do it by clicking on this link.

The program has a library of examples. File / Examples / C.1 Basics / Blink to light a Led

I used this example and I modified the location of the pins and delay values

I started by turning the LED on and off every 1 second. According to the table of conversion of pins that shows at the beginning corresponded pin 11

The first thing to do is click on the check to compile the program, it means to see if there are any errors

Then click the arrow to upload the program. I had to change to pin 13 because when I wanted to upload the program with the pin 11 came out error. Gonzalo Siu, my Fab Academy instructor suggested I try the pin 11 and it worked.

The program was successfully uploaded

And the LED light went on and off every 1 second

So I started to generate different sequences.

With different intervals

Finally this was the code entered.

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DOWNLOAD FILES