Devlog 2, 3, 4, 5, 6, 7, 8

Pretty long header, huh? Let me catch you up. I am running a dual boot with Arch basically, and my Windows 11 partition gets mad sometimes. A few days back it snapped. Yep, it snapped. It destroyed itself and I don’t have enough time to debug the issue and fix it, so I decided… how hard can setting everything up on Linux be? (Big understatement.) Turns out I recorded from the browser for like 4 hours and then the recording completely crashed on me. Thankful for the Stardance staff though, as they said I can just directly add entries to my journal, so here I am!

I got a limit on how much I can type so I’ll be quick.

Devlog 2

I added a boost converter, fuel gauge IC, and an SD card slot. That’s literally it. The reason? I went through 90 different Reddit forums and a few datasheets later just to find out that my schematic is COMPLETELY unusable. Reason? Because the values I inputted were completely wrong and I forgot to account for the actual traces and distance. Yeah… big mistake.
(I’m just exposing myself at this point)
~5 hours

Devlog 3

Things picked up from here. I proceeded to wire up the Neo M9N and also proceeded to wire up the audio and microphone chips. The GPS module took me the most time. I needed to calculate the actual performance in real-world testing because if I didn’t, I would be fried indefinitely. RF signals are too picky.

~3 hours

Devlog 4

Wired up most of the things I got to the CM4 connectors. Not much I can say here. I spent most of the time trying different layouts on where to put it. I was basically shuffling in between the schematic editor and PCB editor (big mistake later, traces got jumbled).

~1 hour

Devlog 5

I realized I AM COOKED if I don’t finish this ASAP, so I started grinding. I rushed through everything and you’ll see why this was a bad idea in a bit.

Devlog 6

I am done with the whole PCB. Time to run the DRC checker. What can go wrong? (Foreshadowing: everything went wrong.) I got like 500 errors and 300 warnings (actual count). The whole problem? I crammed everything TOO TIGHT. So I spent devlog 6 and 7 cleaning everything up.

~9 hours

Devlog 8

FINALLY, MY PCB IS DONE! For my first PCB, this isn’t too bad, considering I did a more ambitious project. I have no DRC errors anymore, so I ran the project inside a simulation. I checked every signal output and power planes/ground planes. Everything was expected except I ran into problems with the SD card trace. I knew this was coming either way. The traces spanned everywhere and weakened the signal. I fixed it right up though, so in theory this thing will boot and run without issues.

What Did I Learn?

Absolutely nothing. (Jk.) I learned to not RUSH. In this case I absolutely had to because if I didn’t, I wouldn’t make the project deadline. Maybe I should have rushed more gracefully, but now I am 3 textbooks down. I wrote like 90% of my schematics on my textbooks and datasheet references until I screwed that part up by not doing math. I thought it’d give me actual good info, not mathematical nonsense. Oh well. It’s finished and I’m proud that I got a device like this done.

Now the hard part: CHEAP SOURCING. Apparently this won’t be covered if it’s too expensive and the PCB isn’t polished, which I can’t say much about because the PCB looks like sh!t. I was not making a Mona Lisa, bro. Now I can make a total calculation. I’ll use AliExpress because those are the CHEAPEST and fastest part suppliers. JLCPCB gets the rest, and once I get the correct amount I’m sending this in. Meanwhile, tonight I’ll work on the GitHub and demo… which I don’t have, so I guess I’ll make a website for the GPS.

Devlog 1: The 43-Minute Charging Core

Project Context & Architecture

I’m designing a custom handheld navigation device from scratch. The goal is a custom carrier board in KiCad that ties together high-performance computing, location tracking, and power management. Here’s the hardware stack:

• The Brain: Raspberry Pi Compute Module 4 (CM4) — Runs the core OS, custom parsing utilities, and handles all the high-level computing.
• Location Tracking: u-blox NEO-M9N GNSS/GPS Module — Connected to an active external antenna for live coordinates literally anywhere.
• Power Management: BQ25895RTWR (QFN-24) — A highly efficient switch-mode 3A buck charger handling autonomous LiPo charging, direct power-path management, and a deep-sleep “Ship Mode” hibernation circuit to prevent battery drain.
• Power Input & Battery: USB-C Interface & 1S LiPo (via JST-PH) — Hardwired strictly as a one-way power sink (charging input only because I have zero motives to actually use the port for anything else).

The Update

PS: My incompetent brain used plain text boxes for my schematic labels instead of just pressing the L key to make actual net flags.

So, here’s what I got done in exactly 43 minutes: a charging circuit. That’s it. That’s literally all I did. Right now, there is absolutely nothing connecting over to the CM4 compute engine yet. I’m an absolute beginner at physical PCB layout, but I am a certified pro at reading datasheets. If you think about it, it’s the biggest engineering bottleneck of the century. Either way, I need to get this entire hardware project finished by tomorrow to actually get this PCB sent over to JLCPCB, get leads on parts, get it shipped ASAP, and take measurements for the enclosure. (That is if I get actual funding..) I’m currently sitting at a solid 5% completion. This is going to be an absolute sprint. (Not like my teachers once asked me to write a drama script last minute that was like 50% of my grade and I managed to pull off a 30-page script in one night… but yeah.) I’ll see you in a bit when I’ve actually got a few more sheets knocked out.