12/31/2025 - Research complete

I did all the research for this project beforehand by first watching this video . What I am going to do is use a common 3.7 V lipo battery along with a tp4056 module for recharge, and the battery will power 8 leds(via led driver), a built in antenna gps module and this all in one imu module as well. Then I can find the bearing using a formula from here.

1/1/2026 - Done with Power management

Finished the power management of the PCB where I choose to use a screw terminal for a 3.7 v lipo which is brought down to 3.3V with a Ldo, and for the lipo recharge I use a tp4056 which receives 5V from a USB-C port.

1/3/2026 - FInished Schematic

I finished schematics, with the GPS using UART (tx,rx) and for the accelerometer I chose to use I2C (Scl, Sda) pins. Along with this I also forgot to add a 1.8 LDO Regulator for the Accelerometer so I added this as well. For the 8 Leds I switched from an LED driver to a shift register instead because it is simpler than using an led driver. Lastly I ended up finding an esp32 that I liked in terms of size and pins choosing the esp32 c3 supermini as it has a 3.3v input pin

1/5/2026 11 AM - Created the PCB Layout

After multiple revisions of changing parts locations over and over again this is what I was left with as my final board layout. The process I used to make this layout was to first group components together like placing decoupling capacitors close to their respective components. Then for my LEDs to create an almost perfect compass like shape what I did was take a 25mmx25mm square and take that same square rotated 45 degrees and used the easyeda center alignment tool to get a perfect 8 pointed star shape in which I could place a LED on each corner. Then I just moved my clusters of components as close as possible making sure to place them in somewhat easy areas both for access and for routing purposes.

1/5/2026 2 PM - Finished all routing and silksreen

I started off by routing all traces that weren't ground and this was relatively easy I only had to move around a few small components and use a few vias for the leds that were directly opposite to the shift register. Then after that I decided to put both a top and bottom ground plane to help with signal integrity but I faced significant problems around the accelerometer section.

There were a lot of ground pads here each being so tight together that if you didnt have a directly open path out of the ic then you would encounter a drc violation. For this I had to keep deleting parts of the ground plane and space out components and the traces to get space for vias and routing. Lastly, I was able to add back the ground planes and added both silkscreen + stitching vias as well.