#hardwaredebugging

[adafruit]

Metro RP2350 take 5 🔄🌟🤞

Sometimes mistakes are made in prototyping; that's why they're prototypes. The error in rev D was funny: while making the QFN80 footprint, the pins got placed clockwise rather than widdershins. Not surprisingly, that board didn't come up at all, so here's a full rip-up and reroute, with the correct pinout this time! Fingers crossed. Hopefully, this is the final revision, and we can move on to other RP2350 boards we have cooking.

[forlinx]

Having trouble with your Forlinx AM62x development board?

Our latest troubleshooting guide covers common interface issues including power checks, I2C & SPI communication, USB & SDIO signal integrity, and more!

Get practical tips to quickly diagnose and fix boot failures and interface glitches.

Perfect for embedded developers working with OK62xx-C boards.

Stay tuned for Phase 2 with UART, CAN, PCIe, and LVDS troubleshooting!

[wizzardx]

The Case of the Vanishing Mouse: When Chrome Eats Your USB Devices

You know that moment when you're 47 Chrome tabs deep into "research" (read: watching YouTube tutorials for hobbies you'll never start while simultaneously checking email, Reddit, and that one website where people draw mustaches on renaissance paintings), and suddenly your USB mouse decides it's had quite enough of this digital circus and ceremoniously disconnects itself?

It's not being dramatic. It's not mercury retrograde. It's a genuinely fascinating hardware quirk that exposes the precarious timing ballet happening inside your computer.

What's Actually Happening

What I've discovered through extensive analysis (and by "extensive analysis" I mean "becoming irrationally angry at my mouse and diving into kernel logs") is a delightful system architecture quirk:

When Chrome tabs consume significant CPU resources (mine were cheerfully gobbling ~44% each), the system experiences microscopic delays processing USB interrupts. For most devices, these delays are inconsequential—like being one person behind in line at the coffee shop. But USB mice, especially low-speed ones, are the technological equivalent of that person who checks their watch every 8 seconds while waiting for the elevator.

The error (-71 EPROTO) translates to: "I asked a question and didn't get an answer fast enough, so I'm disconnecting myself in protest."

The Class Divide of Input Devices

The most fascinating part? Your laptop's built-in touchpad continues working flawlessly during this mouse rebellion. This is because your touchpad lives on computing's equivalent of the Upper East Side—it connects through dedicated internal buses with VIP access to the kernel. When it speaks, the system listens.

Meanwhile, your USB mouse is essentially showing up to the party without being on the guest list, forced to communicate through the baroque bureaucracy of the USB stack, desperately hoping someone important notices its increasingly frantic message requests.

The Fix (Besides "Use Fewer Chrome Tabs" Which We Both Know Isn't Happening)

For those who refuse to close their 83 open tabs explaining why you should close your tabs:

#Tell your kernel to respect the mouse's feelings echo "options usbhid quirks=0x[your-vendor-id]:0x[your-product-id]:0x40" | sudo tee /etc/modprobe.d/usbhid-mouse-fix.conf # Boost USB interrupt priority

echo "options xhci_hcd interrupt=7" | sudo tee /etc/modprobe.d/usb-priority.conf # Refresh your kernel's perspective on life sudo update-initramfs -u

This essentially tells your system: "I don't care if Chrome is in the middle of rendering 47 JavaScript-heavy tabs about cryptocurrency—when this mouse speaks, you LISTEN."

The Broader Existential Crisis

The truly delightful thing about this issue is how it exposes the fragile assumptions underpinning our computing experience. We've built technological cathedrals on the digital equivalent of "well, it probably won't rain THAT hard."

So the next time your mouse vanishes while you're deep in a Chrome rabbit hole, know that you've stumbled upon one of computing's hidden fault lines—where timing-sensitive hardware protocols crash against the resource-hungry realities of modern web browsers.

And remember: your laptop isn't broken. It's just experiencing an existential crisis about resource allocation priorities. Aren't we all?

[adafruit]

Espressif programmer test success! 💻✨🔧

While developing boards, there are oftentimes we want to program ESP chips without going through the onboard USB port; this adapter will help us (and others) do that! It has a CP2102N USB-serial chip

https://www.digikey.com/short/bm7n3p5z

...with RX/TX signal LEDs and two transistors wired up to the DTR/RTS line for the 'esptool standard' reset procedure technique. The output IO, plus a 3.3V 500mA regulated output, is available on a socket header, so you can plug wires in for quick programming and debugging. You can use this for everything from an ESP8266 up to the ESP32-P4! Here, we are testing it with a HUZZAH ESP8266 breakout board

...one of our first Espressif chipset products.

[adafruit]

Ladyada's desk gets a scope cart

We've always wanted a portable scope cart

for our workspace to have our test equipment either by the desk for firmware work or at the soldering worktable for rework debugging. At our new office, we finally have space for one! We picked up this 'dental cart'

- It is not super fancy, but it is metal, and it came together fairly easily. We like the mini top shelf for the scope and the second shelf underneath for the power supply and electronic load. The drawer can hold leads or probes. We've locked it next to our desk so we have more desktop space, and it's easy to peek over as we bring up new boards like the metro RP2350

We'll also get the VGA output into our video streaming setup to show off signals we're working on.

[adafruit]

Desk of Ladyada - Kiddo Kart Repair 🔋👶

BabyAda's bumper car toy stopped working after overnight charging - turns out 24V charger + 12V battery = problems. Quick fix: replaced battery with correct one from DigiKey. Pro tip -Always check voltage compatibility!

[adafruit]

Desk of Ladyada - Solar Boosters, Split Supplies, and a Floppsy rev 💾✨🔋 https://youtu.be/yfdQca-_H4o Floppsy Rev B debugging (floppy pins, power, boot button) & prepping Disk tests. Crafted a split-supply board (-12V throwback to 6.101!) and boosted 5V solar power magic with bq25185 + TPS61023. Also hunting for a modern 5V stepper driver!

[adafruit]

Adafruit BusIO library makes debugging I2C failures fast 🛠️💡🔌

It's not often… but every few months, one of our sensor drivers stops working due to hardware changes. It happened this week with the AHT20 tester - for some reason, it doesn't init anymore! What would typically turn into a multi-hour debugging session is a lot easier since we started using an intermediary library called BusIO for I2C/SPI device interactions https://github.com/adafruit/Adafruit_BusIO - there is a single #define we enable to turn on print debugging and when we recompile and upload - voila we see full translation details including stops and transfer failures. Turns out the secret calibration command no longer exists on AHTs; a quick PR https://github.com/adafruit/Adafruit_AHTX0/pull/13 , and we're back in business!