> Is the USB bus really a good way to get 1 PPS into a machine? I would > think it would have quite a bit of jitter in it.
I'm not a USB wizard, but I work with people who are. There is no interrupt mechanism on a USB cable. The host/master polls the devices/slaves. Typical numbers are 10 ms or 1 ms. At setup time (I forget what USB calls it), the device can tell the host how often it wants to be polled. (I assume the host can ignore that or round up to what it can handle.) For a homebrew project, it might be possible to turn things inside out. Have the host flap a signal, say from the printer port, and the GPS device records the time. Then the device reports that time via USB. One of the popular GPS over serial port devices works that way. (I forget which one.) -- The suespammers.org mail server is located in California. So are all my other mailboxes. Please do not send unsolicited bulk e-mail or unsolicited commercial e-mail to my suespammers.org address or any of my other addresses. These are my opinions, not necessarily my employer's. I hate spam. _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
