Week 6. Electronics Design

Group Assignment

Link to Group Assignemnt

Takeaways: * Before any testing is done, the Oscilloscope needs to be calibrated. to conduct this calibration: connect the probes from your device to the 2V terminal. We used alligator clips to do this. Then hit Autoset.

Individual Assignment

KiCAD

As a beginner in Electronics, I decided to stick with KiCAD as my software of choice for this week.

I wanted to make a board that had the attiny1614 as the micro controller, with the following components: 1. LED

1. Resistor

2. Capacitor

3. Button

4. 3 point connector for a servo motor

5. FTDI connection

6. UPDI connection

I wanted to add the servo motor since my project revolves around drones and I wanted to control the control bodies with servos.

Adrians’ Adrianino was a great source of inspiration as he used the attiny1614 as well.

Work flow:

• Install KiCAD

• Add Fab Library. >I followed the given instructions:

  1. Clone or download this repository. You may rename the directory to fab.
  2. Store it in a safe place such as ~/kicad/libraries or C:/kicad/libraries.
  3. Run KiCad or open a KiCad .pro file.
  4. Go to “Preferences / Manage Symbol Libraries” and add fab.kicad_sym as symbol library.
  5. Go to “Preferences / Manage Footprint Libraries” and add fab.pretty as footprint library. Go to “Preferences / Configure Paths” and add variable named FAB that points to the installation directory of the fab library, such as ~/kicad/libraries/fab or C:/kicad/libraries/fab. This will enable the custom 3D shapes to be found. The 3D shapes project has just started and most of them have to be populated still.

• In KiCAD, open New project

Short cuts:

m = move component

r = rotate component

a = add component

ctrl+c, ctrl v = copy/paste

g = grab component and connection

e = assign value (after hovering over component)

Schematic:

• Choose the .sch file
• Click a and add attiny1614SS (pop up window allows you to choose)
• add a capacitor, resistor, LED, FTDI, UPDI, 3 pin male connector (all from the fab library)
• Quick Guide:
• You can add wires to connect the components or make use of labels
• refer to the attiny1614 datasheet to see what components needs to be connected to which pin.
• create labels for PA0, PA2, PA5, PA7, PB2, PB3, VCC and GND

• Connect all the labels to the necessary pins. >PA0 - UPDI

  PA2 - Connector

  PA5 - LED

  PA7 - Button

  PB2 - FTDI TX

  PB3 - FTDI RX

• do the same with GND and VCC

• add no connection flag to unused pins
• add PWR and 2 GND flags.
• Connect one GND to PWR flag
• add the other GND to the GND of the mcu
• run the ERC from the top right
• assign foot prints by hitting the Run footprint assignment tool
• select which component you want to assign a footprint too, and search for it and apply ones from fab
• Once done, Apply, Save Schematic & Continue
• Final schematic:

Shortcuts:

X: route tracks

u: to select the entire track

d: to drag the components and it’s tracks

m: move just the component

PCB:

• Open the PCB editor
• Hit Update PCB with changes made to schematic or F8 to add all the components from the schematic to the PCB
• move and adjust components keeping in mind where they are
• edit the track width by editing the Track on the top left
• add 0.4mm and 0.8mm and hit ok
• Route Tracks or hit X in the FCu layer. Connect all the necessary components
• go to edits and use Edit Track & Via properties to apply the track widths to all.
• select the edgecuts layer and draw the outline of the board using the line tool.
• I wanted to make my outline the map of Bhutan, so I went to file-> import -> graphics -> in drop down, selected my custom svg and selected edgecutsin the graphic layer.
• Ensure to use 0.8mm track width
• open the Design rules checker window and run the DRC
• I ran the DRC, and ran into an error: No matter what I did, I couldn’t fix it. I tried editing the fill, stroke width but nothing worked.
• I then decided to trace over the map with the line tool and made a rough outline of Bhutan and it Worked!
• In the F.Cu layer, I added the text.
• My Final board:

• Then I went to file -> plot and the plot drop down opened up:
• I selected the format to be svg, and negative plot. I converted the SVGs in inkscape to png/jpg.

• To plot the exterior + interior, I did the same but selected F.Cu and EdgeCuts on plot all layers

• to plot the interior traces and exterior traces separately, I selected both the F.Cu and edgeCuts in the include layers option and unselected them from the plot all layers

  

  

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Extra: Case for the PCB

Made in Fusion 360

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Design files

KICAD Files for the week DESIGN FILES