Hey, fellow nerds!
Long time no see! Or read? But there’s been progress!
Hardware Issues Resolved
From the beginning, one of my motherboards never worked properly with PokyPow power LED detection. So, I sent it over to Soldered, and they figured out the issue!
So my bad luck with the motherboard was actually a good thing. Better I find the problems early than you guys!
Expected Behavior:
A computer is powered on, and a positive voltage is applied to the LED plus pin, while ground is permanently connected. This works perfectly.
The second type works in a different way. A constant positive voltage is always present on the LED plus pin, while the LED minus pin, which is ground, is normally disconnected and only connected to ground when the computer powers on. This closes the current loop and turns on the LED.
Problem:
The optocoupler was tied to ground all the time with the second LED configuration and was always on.
Solution:
Connect the optocoupler cathode to the LED minus pin instead of ground.
Now it’s fixed! This is an easy change and does not require a new prototype run, which is good. Those cost time and money!
Still weird that the LED continuity isn’t in a spec for ATX or elsewhere. Manufacturers can basically do whatever they want, so I am glad I encountered this problem myself and early on.
Another mistake I discovered was that I found out right before I showed the PokyPow at the Maker Faire Ruhr in Dortmund (Germany).
I bought another small Mini ITX mainboard for the demo system I built.
That particular motherboard froze when the PokyPow was plugged in. Nothing worked!
When I removed the PokyPow, the boot continued. Until I plugged the PokyPow in, it was frozen again.
When the OS took over the boot process, the system did not freeze anymore.
It just had a USB device constantly connecting and disconnecting.
Turns out, the USB 2.0 9-pin header connection was wrong. Each row is ONE USB connection.
Scraping off the traces on my prototype board solved the issue.
The demo at Maker Faire Ruhr worked the entire time flawlessly!
Next steps
Now that the known bugs are resolved, I will order the first 100 units to test production.
