Hello Sam, We never did get SPI working though the device file in Angstrom and ended up just bitbanging the same pins as GPIO. Our bitbanged clock signal is wack, but the spi slave we're reading from doesn't seem to mind. Unless someone has submitted some changes to the spi driver in between what I was using and the most recent kernel, I'd recommend you just try bitbanging.
You might try changing the direction of the clock pin to be the opposite of what it should; I think we were at least able to get a clock out, but couldn't read the data correctly. I recently spent some time trying out bare metal, but I didn't even manage to get an LED to blink with TI starterware (BBB is not officially supported yet). Just today I was able to boot into the most recent ubuntu 12.04 image from armhf; I had some stupid hardware problems where the hdmi plug was too big and I could either connect to a monitor or a keyboard but not both :) I will probably not want to mess with the BBB we're bitbanging SPI on again, but if I do, I'll let you know. Cheers, Andrew On Tue, Jan 28, 2014 at 8:19 AM, <[email protected]> wrote: > Have you had any luck getting the spi0 clock working on the BBB (rev A6) > using Ubuntu (3.8.13-bone30) ? I've done all the following > 1) Added "capemgr.enable_partno=BB-SPIDEV0" to uEnv.txt in boot/uboot . > This is the right uEnv.txt file as its in the FAT boot portion. > 2) checking with "cat /sys/devices/bone_capemgr.9/slots" I see the SPIDEV > override > 3) checking "ls -al /dev/spi*" I get the expected "/dev/spidev1.0 and > /dev/spidev1.0" files > 4) I added Adafruit_BB library and the CS pin (P9_17) can be toggled from > here > 5) Shorting pins 21 and 18 I can see data transfer so internally the spi > clock works as expected. > > However connected SPI_CLK(P9_22) to a logic analyzer I see no clock > signal! I am certain the logic analyzer is ok since with hdmi enabled I can > see clock signals on pins 25 and 31. I don't know why I am not getting a > clock signal for SPI0. I just get the clock 'low'. The same thing happens > when I disable hdmi and enable spidev1 instead; I get no clock signal on > SPI1 clock (pin 31). > > Any suggestions on what I may be missing? > > Le mardi 1 octobre 2013 10:55:57 UTC-5, [email protected] a écrit : > >> Rafael, Would you mind posting you DTS file??? I have been trying to make >> the SPI clocl work, but I haven't had any luck! >> >> Thank you, >> >> Laura >> >> El lunes, 16 de septiembre de 2013 07:28:18 UTC-4, Rafael Fiebig-Bindner >> escribió: >>> >>> Just for clearence: Deactivate Pullup/-down is only needed at clock. >>> Am Montag, 16. September 2013 11:22:43 UTC+2 schrieb Andrew Wagner: >>> >>>> Hi Arlen, >>>> >>>> The coverage for setup up a device overlay tree here is pretty good: >>>> >>>> http://learn.adafruit.com/introduction-to-the- >>>> beaglebone-black-device-tree/overview >>>> >>>> With that and glancing at some other samples, we were able to get >>>> writing to work. We did not get reading working in time for our >>>> deadline, and resorted to bitbanging from userspace code. I have not >>>> had a chance to try Rafael's advice (clock as input, deactivate pull >>>> up / pull down). >>>> >>>> Cheers, >>>> Andrew >>>> >>> -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to a topic in the > Google Groups "BeagleBoard" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/beagleboard/NADsTC5Ro-I/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > -- 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 [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
