11/18/2025 - Began research and Schematic

I began looking for parts and creating the schematic. So far, I'm thinking of using a Raspberry Pi 4 as the SBC, a ESP32 as the MCU, and use a LiDAR to do the mapping. These are going to take up the bulk of the budget, meaning I'm going to have to save a lot for the others. There were many revisions before coming to this conclusion. I also decided on getting a 4 GB ram Raspberry Pi, even though it's more expensive, transferring it to my computer is just too slow.
Next session, I am going to do the schematic and get it ready.

11/22/2025 10 AM - Routed the schematic

Today, I finished routing the schematic. First I added many new features, like a Flight of Time sensor to actually guide the robot around as the lidar scans. I also added many small details, like capacitors, diagnostic lights, and switches. I also decided on most of the parts used for the project and a general budget outline. I am currently considering prototyping a PCB but not getting it first, as I want to test out the parts together first on a breadboard. I think the project is coming together nicely, and next I will start working on the PCB.

Main Parts So Far

11/22/2025 5 PM - Finished Schematic

This took a while! I finally finished making the schematic. All the routing should be correct (took a while to learn how to use the design checker), and everything is organized. For many of the pieces, I had to manually create the footprints for my PCB. Let me tell you, searching online to find the dimensions of parts is not easy! I also tracked down all the parts (including the small stuff) and made a rough BOM. So far, I'm around 225.34 USD, which is well within my budget. I'm hoping that this build will be under $300. Overall, I'm happy with my work for the schematic, but again, I want to get the components first and test them out and measure them before sending my PCB to be made. Next, I think I will start creating a rough PCB for the robot!

Schematic

PCB
Click for PCB

BOM

11/22/2025 7 PM - Finished PCB Prototype

Having made some PCBs before, this prototype was done relatively fast. It was very tough to fit everything in a 100mm x 100mm square, as the smallest I could get it was in a 150mm by 100mm rectangle. This shouldn't be very expensive though. I also added a speaker to the system, so now the robot can produce some sound! The next step will be designing the case and putting all of it in a 3D model. To be honest, I am not looking forward to it as I'm trying out a new CAD software, FreeCAD (As Fusion lags my computer too much and I'm on Linux). Hope I survive this. 😬

Schematic

PCB
Click here for PCB

11/22/2025 10 PM - Making the CAD - Part 1

First update on the CAD! I have gotten the PCB and some components including the PI, ESP, and Motor Drivers into FreeCAD and assembled. Wow, I really didn't know how hard FreeCAD was, all the tree stuff was extremely confusing. But I think I understand it better now, and it's becoming easier to navigate the interface. I also noticed that the pinholes for the ESP might be a bit too small, but it's like a few micrometers of difference, I think I should be able to shove it in all right. Next update, I should be done assembling the robot, just nothing on the actual shell.

CAD So far

11/23/2025 - Making the CAD - Part 2

I realized that there are many issues with my PCB! For the terminal blocks, the holes are the wrong length apart, so they don't really fit. Also, a lot of the holes are too small for the headers, I'm going to have to change that. The header for the T-Plug is also way too small! I'm going to have to increase it by a lot. So far, those are the problems I find, but I will add more if I find more. Next, I think will try to finish the CAD, very big task but if things go smoothly, things should work.

I also started the actual 3D print part!

11/24/2025 2 PM - Making the CAD - Part 3

This is taking a lot longer than I thought! I fixed the PCB, and it should be good now. It was extremely difficult getting the values correct as the ruler on the PCB maker on KiCad won't stay, so I have to approximate every time. FreeCAD isn't any better, though, learning how to use the ruler was extremely weird. I have to manually select the mode, as the default “Auto” doesn't know what it's doing. On another note, I learned how to auto route for the PCB in KiCad, my wiring looks so good now! It was kind of odd getting it to work in Arch, but it worked out in the end. Hopefully next time, I will be done, or very close to finishing the CAD.

Schematic

PCB
Click to see PCB

CAD
Click to see CAD

11/24/2025 8 PM - Making the CAD - Part 4

It's almost done! The CAD is at the point where it is so complicated that it's starting to lag my computer :(. I really have no idea how much pain I would be in if I was still using Fusion. I was able to resize the entire thing (The frame was way too small, I didn't consider the cables, in the original design, the USB A cable would have been stuffed into the wall), this took a long time, as I had to rearrange everything, and make sure the screws still went into the holes. Speaking of screws, I also added brass fittings, that way I don't need to use nuts in weird places. The Lidar was also added with a mount that I found online, theres a small space inside the mount to put the converter and wires. Finally, I added the TOF sensor and mounted it inside the wall, that way it can see the outside and not be damaged by the outside. I also added a roof.
Hopefully, next session is where I will of finished the CAD and moved onto firmware!

CAD

11/25/2025 - Making the CAD - Part 5

Finally!!!! I've finished the CAD!!! This took so long, I'm about to go insane! I added a bunch of small stuff this session, including the back wheel (it was the front wheel, but I moved it to the back for better stability (changing the screw holes was so annoying)), added the switches to the top (I decided not to have the LEDs shown as it would be too complex to wire/tube the light to the surface), added small components like the fuse, added bigger components like the Raspberry Pi fan, and added some cute googly eyes. Then I refined the case a bit, filleting the sides and making the thing look good. I also added some colour to some parts, changing the default grey to a sleek black. Overall, I am very happy with how it turned out. Now there is just one more step, writing the firmware, then I'll be done! :)

Some nice pictures of the CAD Model

11/26/2025 - Shipped! (Plus firmware)

Hopefully the last journal entry before the actual build! I was able to quickly get a firmware base for the project through PlatformIO for the ESP32. Then I spent most of my time trying to figure out how to upload the huge .step file onto GitHub. It was different from when I had Windows, so I basically had to relearn it. But before even that, trying to download the .step file was a huge hassle. One being that apparently my project had meshes in it, and I didn't even know, so I had to spend time learning how to turn those meshes into solid shapes before I could download the entire file as a STEP. The rest went pretty smoothly, and I added a readme file and shipped the project. Many of the links of the product didn't work anymore from before, so I had to find new ones. Everything should be under 300 dollars, including the PCB. Hopefully the project gets accepted!

Final Product images