Electronics is the branch of physics and technology concerned
with the design of circuits using transistors and microchips,
and with the behavior and movement of electrons in a semiconductor,
conductor, vacuum, or gas.
Group assignment
- Characterize the design rules for your PCB production process: document feeds, speeds, plunge rate, depth of cut (traces and outline) and tooling.
- Document your work (in a group or individually)
Individual assignments
- Link to the group assignment page
- Document how I made (mill, stuff, solder) the board
- Document that my board is functional
- Explain any problems and how I fixed them
- Include a ‘hero shot’ of my board
Don't know what these people is talking about.
During the pre fab we made some warm up exercises to understand this new language, at the beginig found ir really hard to understand because I've never done something like this before, but now it is starting to make sense. You can find the details of this previous process HERE
Find out the details of our common work al ZOI Here.
To understand the components I found these sites with definitions, it may seem very basic but it's been usefull.
Símbolos eléctricos y electrónicos.
Understanding little by little.
I'm completelly new in this field, so to start I'm just following instructions as told.
This link was really usefull to understand what to do and how to do it
Building the FabTinyISP.
The FabTinyISP is a "low-speed" USB 1.1 device. This is the slowest (and one of
the oldest) of the USB device types. Typically used for mice and keyboards,
low-speed devices operate at 1.5MHz and have much less strict timing requirements,
which enables a purely software-based implementation of the USB protocol to be
used (the ATtiny45 does not have hardware USB capability).
First, what is a pcb? A printed circuit board (PCB) mechanically supports and electrically connects
electrical or electronic components using conductive tracks, pads and other
features etched from one or more sheet layers of copper laminated onto and/or
between sheet layers of a non-conductive substrate. Components are generally
soldered onto the PCB to both electrically connect and mechanically fasten
them to it.
To create the traces and board outline I had to download the files here:
I added my initials on the board using illustrator, and exported as png.
You can find the file here:
Illustrator file.
Once we had the file ready we used mods to generate the G/code. On mods follow this steps:
In mods, select the png file, set the parameters for the mill raster and the path for G-code. Once everything is ready press calculate and you'll get a simulation of the code in an pop up window.
Same steps for the contour, but different parameters:
A G-Code simulator is a type of software tool that provides a virtual representation of a CNC machine's tool path made by following the instructions in a G-Code file. They range from simple simulators that output a single image of the tool path to complex tools that can detect collisions and plot the path in 3D.
To make sure the parameters were right I used a G-Code simmulator, avaliable
on this link:
G-code simmulator
The auto leveler, leveling instrument, or automatic level is an optical instrument used to establish or verify points in the same horizontal plane. It is used in surveying and building with a vertical staff to measure height differences and to transfer, measure and set heights.
To ensure that the tracing lines are even it was necessary to do an autoleveler.
For this we installed it and load the .nc file with the traces, set the parameters
and generate the autoleveler.
We used the cnc machine which I find very precise and usefull in so many scales because
the other machine for tracings wasn't working. These are the steps needed to mill the board:
The next step is to cut the outline, to do this it is necessary to:
The tools we used for engraving and cutting the board:
The result looks like this:
Make sure to have all the components. This is the BOM (Bill of Materials)
To assembly the parts to the PCB it is recommended to start from
the center towards the ends and from the top to bottom (Reminding Neil's words).
Another recommendation is to start with the most difficult parts, in this case
it would be the ATtiny45 so you can have more accesss for the rest of parts and
leave the IPS header last, because of its big size it can be an obstacle for
the rest of components if you solder it too early.
The ATtiny45 has a dot on a corner, which was easy to find and orient
in the board.
I was told to pay attention to the correct orientatio of the leds and the zeener diodes.
The zener diodes are marked with a green line and to make sure I used a
multimeter to check them.
Added the resistors, starting with the 1kΩ, then the 499Ω and finally the 49Ω.
I confused the resistors and once soldered I had to detach them (a difficult job) and reposition them correctly.
Then added the leds, capacitor, made a bridge and finally the pin header.
This is the final result of my board after some corrections from my tutor.
Quality is lacking in the welds, it was not an easy job, especially when I had never tried it before.
However I find it interesting and motivating to keep trying. I understand that I still have a lot to learn in this field
but I'm pretty happy with the result.To improve the welds, the recommendation is to put the tip of the soldering in touch of the board and the component
before adding the soldering tin.
I have a nice annecdote, when we prepared the resistor at the lab we mixed the 49.9 and the 499.
I couldn't really see the difference between both of them, so i just followed the example and
assembled my board. Turns out my board was the only one with no mistakes.
Before doing anything it is important to check the board, these are the recommendations:
Alex is a former student very skilled in programming. He helped us in this process.
He has his own programmer which helped us to program ours and gave me the files (you nedd a former programmer to programm your programmer)
Following the instructions from this site Building the FabTinyISP.
In the programming section you can find this link
to install the software needed Using the GNU AVR toolchain on Windows. The recommendation here is to install:
In the same FabTiniISP page you can download the make file, then follow this steps:
😌
The following video shows a simple programmign I tryed using my outputs board from week 12 . It is an blink exmaple from Arduino IDE.
The connections I made are based on the following diagram taken from electronica guru.
and connected them to my board.
In Arudino IDE, the steps are pretty simple to follow, I found the information in this site Burning sketches to the Arduino board with an external programmer
The following video shows the result:
This has been a week of mixed feelings, on one hand I am excited about the first part of the exercise, engraving the plate, soldering the components, I enjoy this process.
On the other hand, the programming part is still very complex for me to understand (even from the simplest things like understanding what a "hexa" is).
Fortunately, the Building the FabTinyISP page is very detailed and easy to follow and my classmates have been really helpufull throughout this process.
There are many concepts that I find difficult to understand, which takes me a long time to investigate and process little by little, I hope that the next few weeks this improves.
