So another rev? Beyond the resistor value issue with the old board, it had some issues that made it expensive and harder than really necessary to build.
Main difference in this rev is the switch from optoisolators to digital isolators. These digiral isolators basically seem to be a modern version of the ancient isolators that used transformers, the coupling is done via RF. I wasn’t able to get any samples, so I’m just going to get some and see what happens. Should save about 3$ in qty 1, and a little bit of power at runtime. The digital isolators are also /way/ faster, 150 Mbaud vs 5Mbaud.
I experimented with autorouting this time. It seems to work well as a helper, and with a lot of even with a lot of tweaking before and after it did speed things up some. It is also helpful to see if a rough part placement will work at all. I also made the pads on the MCU and oscillator bigger, 2 of the parts that were the hardest to place
This opened up some more space in the layout, I was able to get a single 6 channel package, freed up some much needed tool room near the USB header. I also was able to move one of the filter caps out of that ratnest. This version also has 3 mount holes.
I may still replace the USB header before I consider this rev done, I don’t like the current connector I am using, and think that micro usb would be more convenient anyway.
