electronics design

Group Assignment

• Use the test equipment in your lab to observe the operation of a microcontroller circuit board (as a minimum, you should demonstrate the use of a logic analyzer)
• Document your work on the group work page and reflect what you learned on your individual page

Group Assignment

• Use an EDA tool to design a development board that uses parts from the inventory to interact and communicate with an embedded microcontroller
  • simulate a circuit
  • use an EDA tool to design an embedded microcontroller system using parts from the inventory, and check its design rules for fabrication

• extra credit: try another design workflow

• extra credit: design a case

The Group Work

Link to our group page here

Multimeter

• Voltage measured in Parallel - it changes as you go around the circuit
• Amperage in series - have to disconnect something and make it part of the circuit - amperage should be the same all around the board in a series circuit
• Continuity - is the wire connected all the way through - does it beep?

Oscilloscope - in voltage

• High is up at the top
• Low is down at the botoom

The Individual Work

My asset files are here.

Revisiting the Electronics

I wanted to start working on my final project set up. I merged some code from a previous week together. I merged some output code and wifi code together. The communication is there, but I need to remember how to get the wiring of the stepper motor working again. Last time I drove the stepper with an arduino and parts from an Elegoo kit that I had. Then I drove a NEMA 17 that was already hoked up. This time I want to use my parts that I am thinking to use in my final project.

Claude PROMPT: Wiring and pin suggestions for connecting an ESP32C6 to a motor driver to HW-134A module to a NEMA 17 motor

Claude gave me some ideas, but as I was finding my power sourse and looking at my motor, I found another driver that had much easier connections and a place to directly attach the cable from the motor. My thoughts were to start easy and then get more complicated. I uploaded a picture of the driver and used the prompt below.

Claude PROMPT: swapping out motor driver for one with easy attaching ... what kind of motor driver is this and what do i need to change to work with it

Claude led me through the wiring and the set up, but the motor just wouldn't move.

In the next two hours.. I changed the steper driver to an A4988. With this change I was able to get the motor moving following this tutorial and changing it up a bit. However, this one was moving 1/3 of the way around, not all the way around. I noticed that it worked better when I was touching some of the wires. So I thought maybe it's a connection issue.

I changed the bread board to a newer one that I had I swapped out wires.. I started playing with the different wires on the board to figure out what was making the motor start and stop. Still the motor was going in thirds and a bit glitchy.

When I did this board switch, I accidentally reversed the power cables on the VDD side. (Exactly what my isntructor warned me about with motors) I noticed lots of heat and quickly disconnected the power and CAREFULLY revisited all my power connections.

Still a bit glitchy, I decided to change the step pin ..... and by the grace of the spaghetti monster, my stepper is making full rotations back and forth. STill a bit glitchy, but I adjusted the onboard potentiometer and now it is working pretty smoothly. I will add somebutton controls and call it good for designing the board.

Originally, I asked Claude for suggestions on pins becuase I found the number of options on the pinout a bit overwhelming. Conclusion: Claude is not good with pins. First, claude told me that I should use pins that were on the back, and one that didnt exist (GPIO3).

KiCad

Now I need to review my KiCad tutorials to get draw this up.

In Prefab I watched the above KiCad tutorials. Then I went to get KiCad library from past student., Omar-albalbaki 2025

KiCAD (Install & Fab Inventory Library & Schematic & PCB )

Adding the Fab Academy Inventory Library To make my experience smoother, I added the Fab Academy component library to KiCad. I followed the step-by-step instructions from a GitHub repository.

https://gitlab.fabcloud.org/pub/libraries/electronics/kicad

• Clone or download this repository. You may rename the directory to fab.
• Store it in a safe place such as ~/kicad/libraries or C:/kicad/libraries.
• Run KiCad or open a KiCad .pro file.
• Go to "Preferences / Manage Symbol Libraries" and add fab.kicad_sym as symbol library.
• Go to "Preferences / Manage Footprint Libraries" and add fab.pretty as footprint library.
• Go to "Preferences / Configure Paths" and add new environment variable "FAB" that points to location of the fab library on your drive, e.g. ~/kicad/libraries/fab. This is needed for the 3D models to load correctly.

I imported the schematic symbols and footprint libraries to ensure that all necessary components were available for PCB design.

Other Tutorials that i Found online to help me learn to use KiCad Kicad Design Guide

I also found this one with PDF’s that i could download. Documentation | KiCad

This is great.. Because i was trying to work and learn on a plane flight, and i didn’t have wifi other than the AA online entertainment. I also went to Barbara Morrow’s site to see where she learned. I agree with her that using the PDF is easier for me also than the video because you can refer back to what you learned a bit easier.

Wires - I had stacked wires - so I couldn't get the LED net to get labeled correctly used claude to troubleshoot.. And then fixed.

Could never get the via to work on the first round.

When I made a switch in the end of the tutorial and then placed it, I was able to get via to work. I think I needed to place the wire and then add the via perhaps. Tutorial Board below - with switch that I made in a practice library and made the footprint as well.

Additional learning resources suggested [Learning Resources | KiCad] (https://www.kicad.org/help/learning-resources/)

Another Kicad starter guide Kicad Design Guide

When I came back to KiCAD this time, the software asked me to update and when I did, I lost my fab libraries. I went back in and followed the instructions on the readme and given in class to reload the plug in. Once I got here, I went to insert the esp32c6 seeed module, but it was not there. I reached out for help on mattermost.

When I got back to the lab and talked to Tom Dubick, he suggested that I get the information from seeedstudio.

SUPER - now I had two choices to continue to work on designing the board in KiCAD. USe the Seeed that is there, or go get the ones off the website. I decided to check out the website and see if I could find the ESP32C6.

After finding them, I needed to figure out ow to import them into the KiCad. I used manage libraries in the tools area to add the library. Unfortunately, the footprints didn't import with them. I added the foot prints library, but they did not merge together.

With the imported seeed selected, I right clicked and used edit Main Fields. Then selected footprint.

Then when the diagram came up, I was able to navigate to the foot print and add it to the component.

After finishing all the components that I currently have, I decided I would like to make it possible to add other components to my board easily. Unfamiliar with the different connectors, I asked claude to help me choose the best connectors to add to my board from the Fab Academy library on KiCad.

PROMPT: i would like to add 4 pin connectors to my pcb board to be able to add other sensors and components later. which connectors would be the best fit from the fab academy kiCad library

Claude suggested Part Name: Conn_01x04_Pin or HEADER-1X4

I moved around a couple of connections to have two open pins together and then put two more connectors on the other side.

With my first bring in from schematic, old parts that I no longer had in my schamatics were still there.

Then I did a second update from schematic and it brought in my new parts, and then I manually deleted my old parts.

As I was starting to work on the traces, I found that I had duplicates.

Everywhere that I saw the circle, I selected and checked for duplicates. I deleted many and rewired. Then I also realized that I was going to need to change my pin layouts and connections in order to prevent wire crossovers.

I was able to route the ground under the Motor Driver to connect the grounds and to connect the microsteppers to the ground as well.

I ran the Electronics Checker and found a few errors around the power markings and learning about using the power flags to show the current was running through the circuit.

Then once the power markers and flags were added.

There were still a couple of errors but those were just warnings that are fine to leave alone.

I ran the Design Checker once all mytraces were done, and then moved a few things around. It reminded me that I needed to cut the board.

There were two warnings about my silscreen being close to my solder pads. I was ok wtih that.

I asked Claude to let me know what or if to do anything about these errors.

PROMPT: explain these errors and when i should be concerned

Claude explained that this means the white silkscreen text/graphics on your ESP32C6 footprint overlaps the solder mask openings (the exposed copper pads). The silkscreen gets physically cut off where the pad is. This is cosmetic only — it just means a label or outline might look truncated on the finished board. Not a problem for functionality. However, it noted that i wasnt checking the errors and those were more important. I checked those errors and they didnt apply.

They were about pins that aren't connected by design, or arose from only one point to connect to in the schematic when the switch has 2 points on each side (total 4) in the PCB.

After I had a final design, I decided to make a cut out that matches my overall theme. I was able to get a lateral brain svg and use inkscape to cut out the middle and use the outline to make my edge cut layer. I used import graphic and then scaled it to 50% and then "F" to flip the outline to fit better with my circuit.

Wokwi Similation

After looking into the other simulation programs, I found that Wokwi was the only one that really worked well with the ESP32c6, so I started a new file with my new lay out. After a few attempts at wiring, I figured out that the beta mode of creating a joint for wiring really wasnt working that well, and that it was better to just put the wires on top of themselves all the way to the pin. I also started renaming the pins to the numbers that came up when I was connecting to them. This was incorrect and the program would not run. I went back to my pinout diagram.

After I changed the numbers back to thier GPIO numbers, the program worked as it did in my physical set up.

Case Design

I se onshape to design a case. I had someissues withimporting the image becuase it was an SVG. It brought it in as a separate tab which i couldnt use in my sketch.

Then I did some internet searching to infd the onshape help area that said i shold bring it in as dxf. I went back to inkscape and saved as a dxf. I changed my workspace units in onshape to mm and also imported in mm. This worked, but it brought me to screen I have never seen before.

It was still large but not terrible. I was able to bring it into my sketch using the "use" command. I then used the transform command to move it and shrink it. Then I used offset to make walls. Then I cut a hole for the USB C. It will have to be routed a rounda bit in the case, but it made the most sense for it to come out the stem. V2, I would reposition on the board for the USB to be at the bottom maybe. In practical use, the code will be on the chip and only the power will need to come out.

We will need to wait for a couple weeks until we mill these boards to see how it fits. :-) The walls are thin, but its pretty cool.