K0SWE Blog

My work on splitting out individual prototypes of the USB hub, serial adapter and sound card has paid off! I have working prototypes of all three, and a lot more experience with what support components are necessary and which are just "nice to have." Based on this new experience, I've started reworking my original design. I also tried out JLCPCB's assembly service, and while they probably can't build the whole thing (don't have all of the parts I need in stock), they can at least get all of the teeny tiny 0603 resistors and capacitors. Onward!

I haven't been on the air very much over the last month or so. I've been focused on continuing with my custom radio interface PCB project. It's proceeding well and I gathered a lot of good advice, but I also realized that there are plenty of unknowns working with new integrated circuits. Do I pull this mode pin high or low? Does the power input need to be buffered with capacitors or can I get away without that?  Because of all these unknowns, I decided to take one step back and try to create my own evaluation boards for each of the three major components: a USB hub, a USB sound card, and a USB to serial converter. That's essentially what I already have with my consumer devices, but now I'll try to build my own versions of these from application notes and validate each of them individually. That also relieves pressure to get it right the first time in the final form factor that I want; the evaluation boards are not going to be used in the field, so there's no ne...