#hardwareengineering

Metro RP2350 take 5 🔄🌟🤞

TLV320DAC3100 take 2 🎧🔊

After much wrasslin’ with the TLV320DAC3100, we finally have a library that properly configures the PLL and sets up both the headphone and speaker output well enough. However, we made a mistake with the headphone wiring, accidentally swapping ground and mic, and we’re experiencing some noise in the headphones when the Class D speaker output is active.

We’re rerouting the board to separate the speaker outputs from the TRRS jack to address this. While at it, we’re also exposing the MICDET and bias pins—interestingly, the mic detects can double as a potentiometer input for volume control. The board grew by 50 mils, but we believe this version is the one. After testing, it should be ready for sale.

The first test for our WLED board codename "Sparkle Motion" 🌈💖💡 … 🐇⏳🌌

We got our WLED-friend PCBs today, and we only made one mistake: the wrong resistor on the 3.3V feedback line. Now that it's fixed, the board seems to work great with the latest version of WLED

We are checking all 4 signal outputs with this handy 256-LED grid that sits on our desk. Next, we will test the onboard IR receiver, USB PD, I2S microphone, extra I/O pins, and I2C. We'll also do an Arduino IDE board definition in case folks want to use it as a generic ESP32-to-LED-driver board. We're calling the board "Sparkle Motion" for now, but if you have other naming ideas, let us know - if we pick your name, you get a free board

TPS65131 split boost converter revision ✅🔧

TPS65131 Split-Output Booster Supply

Generating a negative voltage over -5V is kinda annoying: most chargepumps max out at 5V inversion, and ones that can double-then-invert like the MAX232 aren't high current. We bumped into the TPS65131

https://www.digikey.com/en/products/detail/texas-instruments/TPS65131RGER/1672464

while working on our Floppsy design

Circuit boards are inspected and validated through visual inspection, automated testing, and electrical verification to ensure reliable performance before production. Engineers check component placement, solder quality, circuit connections, and signal performance using tools like AOI systems, multimeters, and oscilloscopes. Proper PCB validation helps reduce defects, improve reliability, and ensure long-term electronic performance in real-world applications.

Small electronic components should be handled with clean hands, anti-static protection, and precision tools to avoid damage—always use tweezers instead of fingers for tiny parts, work on an ESD-safe surface, and store components in anti-static containers when not in use; avoid applying excessive force or heat during placement and soldering, as delicate chips and connectors can fail from pressure or overheating; using magnification tools and proper lighting also improves accuracy and reduces mistakes, helping ensure reliable PCB assembly, repair, and long-term electronic performance.

Handling electronic components safely starts with controlling static electricity and using the right tools—always work in an ESD-safe environment, wear an anti-static wrist strap, and avoid touching component pins directly; use tweezers for placement, keep your workspace clean, and store parts in anti-static bags when not in use; when soldering, apply controlled heat with a temperature-regulated iron to prevent damage, and never force components into place as this can break connections or internal structures; careful handling not only prevents immediate failures but also ensures long-term reliability and performance of the circuit.