On Friday, July 7, 2017 at 1:53:10 PM UTC-7, Jeff Albrecht wrote: [...] > Are there any other changes that I may have missed? Suggestions? >
Regarding the SPI test in Exploring BeagleBone Black. Got it, works on my machine now! Thank you William and Gaurav for your input. It turned out that the default clock speed in the spi595.c code was to fast for the 74HC595N I am using. I changed it down from 1mhz to 10khz. I powered it from 3.3vdc. If I'm reading the data sheet correctly it looks like it should be able to do 4mhz at 2vdc. Perhaps this chip was a reject or counterfeit? Perhaps the setup on a solder-less breadboard had some negative effect. Or??? <https://lh3.googleusercontent.com/-to2ooT_wnU8/WWV_irmmMbI/AAAAAAAABOY/0V4VnrV1aUE7GuIFIqHRQXmDj7jBbiYfwCLcBGAs/s1600/74HC595N%2BData%2BSheet%2Bdetail%2BMhz.JPG> // transfer.speed_hz = 1000000; //the speed in Hz transfer.speed_hz = 10000; //the speed in Hz # in lieu of loading a device overlay I used config-pin to configure SPI. - Thanks Drew pdp7 $ cat /etc/dogtag $ BeagleBoard.org Debian Image 2017-03-19 $ uname -a $ Linux beaglebone 4.4.54-ti-r93 #1 SMP Fri Mar 17 13:08:22 UTC 2017 armv7l GNU/Linux $ config-pin -l P9.17 #SPI0_CS $ config-pin -l P9.18 #SPI0_D1 $ config-pin -l P9.22 #SPI0_SCLK $ config-pin -l P9.21 #SPI0_D0 $ ./spi595 Along the way I learned how to use the SPI decoders on my Saleae logic 8 and Rigol DS1054z <https://lh3.googleusercontent.com/-p176G8WaVY0/WWV76TarxoI/AAAAAAAABOM/dtZJK0rq2k8DsaYSqYr6M5XOYxmynekEgCLcBGAs/s1600/SaleaeSPI595CounterCapture.JPG> <https://lh3.googleusercontent.com/-xH5veUYeCh8/WWV7w4JrE0I/AAAAAAAABOI/0ZOJBX8eNtAH0_W-Dgox76RBpE2o4BMFACLcBGAs/s1600/DS1Z_QuickPrint5.png> -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/abadd68f-63b4-4c59-aff0-31808c257478%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
