I've got a Pi3 here on my desk. I only see one UART that connects to GPIO pins. But it turns out if you actually need to use serial you use the USB to serial dongles. If you need four serial ports use four dongles. That is just the way the Pi3 is.
You can level the 3.3 volt serial port but then you are into a MAX chip and some passives or maybe just a couple transistors but the =USB-Serial dingle is easier then level shifting. If you want a Pi-like device that is better for real-time embedded use look at the Beagle Bone Black. But it was limited CPU and RAM compared to Pi3 but better IO. If you are building a NTP server, look at the Pi Zero version 1.3. $5 each. On Thu, Jun 22, 2017 at 7:51 PM, Orin Eman <orin.e...@gmail.com> wrote: > On Thu, Jun 22, 2017 at 5:36 PM, Mark Sims <hol...@hotmail.com> wrote: > > > > > The PI does have a couple of logic level serial ports on the expansion > > connector you can connect a level shifter two. One port is normally the > > Linux serial console which you can configure to be a general purpose -- Chris Albertson Redondo Beach, California _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.