[time-nuts] 5370 firmware hacking status report

[John Seamons]

On Jul 24, 2011, at 2:40 PM, Poul-Henning Kamp wrote:

> Ethernets big advantage is that it is galvanically isolated, USB is not.

You had mentioned this issue in February. And since I currently flash using USB I went ahead and bought the evaluation card for the Analog Devices ADuM4160 power/signal isolator chip (see last pic on jks.com). Even though I programmed the GPIO pins on the micro for open drain I didn't know if the +5 on the USB from the host computer would fight the signals from the 5370. Plus I didn't want the ground loop. So the isolator chip splits the power domains and the micro is powered by +5 from the 5370. Works great. But I haven't found anyone who sells the chip in small quantities yet.

You also had mentioned PyRevEng back then. I will try it. It will be very useful at this point.