On 26/10/17 22:11, Chris Caudle wrote:
The processor you mentioned has a Cortex-M7 at 300MHz. BBBB has a Cortex-A8 running at 1GHz plus a Cortex-M processor available as a coprocessor. Peripheral set is pretty comparable, and you can buy BBB at retail for $50 which gets you the faster higher class processor, 512MB of DRAM and 4GB of flash. It runs linux right out of the box so you basically power it on and have NTP running.
The BB Green is even better value for money, and why would we need HDMI for timing apps ? (It also simplifies doing my Poor man's TIC!)
On my list of projects to work on is a cape for BeagleBone Black that takes 10MHz and 1PPS inputs along with a couple of RS232 converters for the UARTs so you can connect a GPSDO to a BBB to make a time server. In my estimation that seemed like the best return on effort.
Wheen you get around to it, *Please* consider: 1) multiplying that 10MHz up to 24 MHz as an option 2) RS422 option instead of RS232 (for the Lucent/HP GPS/Rb boxes) 3) PPS routed to TIMER4/5/6/7 rather than any old GPIO 4) Cover _all_ UARTS, even if serial headers are needed, rather than 9-pin D connectors 5) Some method of dropping a 5V PPS down to 3.3V (2N2222 comes to mind, as does a /2 voltage divider [2.5V is sufficient to trigger the GPIO pins], I have done both - and yes measured the delay through the 2N2222!) (Sorry Chris, I was looking at the serial cape options earlier today to try an santise my lash-ups, and was most disappointed!) Iain _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
