10/3/2025 - Design PCB Schematic & Initial CAD

I designed the PCB schematic today and made a simple first CAD housing for it (see pictures below). I used the datasheet provided by the transparent OLED seller with a 30-pin ESP32 Devkit V1 board to design both the mechanical model and the PCB schematic. I learned that, even for a board so common as the ESP32, there was no 30-pin schematic/footprint available, so I had to make my own using a caliper measuring tool. I also made the transparent OLED display and power supply schematic, but I had to wait until some parts arrived to get some accurate measurements for the transparent OLED and power supply.

10/13/2025 1 PM - Made Footprints

After designing the PCB schematic, I proceeded to design the actual PCB footprint using a caliper and the actual transparent OLED display, which had just arrived. Before I did that, however, I tried to test the actual display to see if it would work, but I didn't have the right materials to do so. I first took measurements and added them to a Google Drawing so I would have all my measurements in one place to create my footprint more easily. See below:

After that, I designed the footprints for the transparent OLED display PCB adapter, the ESP32 (30-pin) that I had (apparently, there weren't any footprints for it online, which surprised me since it seemed to be a common board), and a simple through-hole mount for a 12V power source.

10/13/2025 2 PM - Finished PCB Layout and Routing

Over the long weekend, I decided to finally finish the PCB. I made both the PCB layout (i.e., arranging the parts) and the PCB routing (I was using KiCad, so I manually routed it).

For the layout, I had to try a few different configurations to find out what would work for my situation. Unfortunately, the cable tying the transparent OLED display to the PCB was not very long, so I had to arrange the PCB adapters in such a way that they would allow all of the displays to fit together.

I then decided to route the PCB manually so I could get some practice with manual PCB design, and partly because I was too lazy to download a KiCad autorouter (I also didn't trust it). I noticed that the ratsnests for the grounds all pointed to the closest ground, which I perceived could be an issue for capacitors. However, KiCad still pointed the ground pads to the closest ground after fixing the schematic to be directly connected to a specific ground, so I continued and hoped it was ok.

10/27/2025 - Tested the Module

I tested the transparent OLED module which had arrived at my house a while ago. Using my school's robotics lab and a 12V lead acid battery I had, I used my schematic and the datasheet to hook up the module. I also soldered some header pins onto the PCB adapter that came with it so I could connect to it. The first time that I tried to hook it up, it didn't work, and the module wasn't even warm. I knew the job that I'd done was pretty rough, so I took it apart and did a cleaner job using a breadboard. Though I was wary about passing 12V through a breadboard, I was able to bypass directly passing that much voltage through using a split dupont cable - one side to my battery, one side to the breadboard, one side to the module. I haven't had the chance to test this yet since I didn't have the right ceramic capacitor, and the alligator clips haven't arrived at my house yet, but when they do, there will be another update on this journal.

1/12/2026 - Tested some more

Ok, it's been a while since I've done a journal, but that's just because I was too lazy before. Back in October or November, I tested the transparent OLED display a lot more, and unfortunately, the display still hasn't lit up. I'm convinced of either two things: either the display is fried, or my capacitors and resistors are introducing time delays that offset the SPI hex commands. Given that I've followed the datasheet application directly, something I could try is just running the module directly without an application circuit.

Tools that I learned to use during this period was a logic analyzer for my SPI circuit and the libraries for the SH110X adafruit and general OLED display libraries. It was pretty insightful to learn these tools and use the datasheet for evidence, but I'm starting to think they could be misleading...

PulseView SPI Logic Analyzer Software:

Adafruit-SH110X Library:

1/15/2026 - Routed the PCB again (:sob:)

I had to route the PCB again since, through testing, I realized that the manufacturer wrote the pin numbers wrong. Unfortunately, I lost the 50-50 of if I had based my PCB off the right pin numbers or not, so I had to spend an extra hour routing the PCB. It's alright, though! It was pretty satisfying. See below: