Please disregard... I had a strange hardware grounding problem that allowed "i2cdetect" to see the part, but could not communicate with the part. I2C working as expected on the PocketBeagle, now.
--- Graham == On Sunday, October 22, 2017 at 9:00:57 AM UTC-5, Graham wrote: > > I am trying to run some Python control of I2C devices on the Pocket Beagle > (PB) > that already run on the BBB (Rev C). > > So, I set up the following comparison: > > ---------------------------------------------------------------- > > Load fresh "bone-debian-9.2-iot-armhf-2017-10-10-4gb.img" on the BBB Rev.C > > Linux beaglebone 4.4.91-ti-r133 #1 SMP Tue Oct 10 05:18:08 UTC 2017 armv7l > GNU/Linux > > sudo apt update > sudo apt install python-smbus python3-smbus > > i2cdetect -y -r 2 # reveals target part at bus 2, addr = 0x18 > > python2 > >>> import smbus > >>> b = smbus.SMBus(2) > >>> print b.read_word_data(0x18,0x06) > 21504 > # expected result (Manufacturer ID for MPC9808 temp sensor) > > python3 > >>> import smbus > >>> b = smbus.SMBus(2) > >>> print (b.read_word_data(0x18,0x06)) > 21504 > # expected result (Manufacturer ID for MPC9808 temp sensor) > > ---------------------------------------------------------------- > > Load fresh "bone-debian-9.2-iot-armhf-2017-10-15-4gb.img" on the PB. > > Linux beaglebone 4.4.91-ti-r133 #1 SMP Tue Oct 10 05:18:08 UTC 2017 armv7l > GNU/Linux > > i2cdetect -y -r 2 # reveals target part at bus 2, addr = 0x18 > > sudo apt update > sudo apt install python-smbus python3-smbus > > python > >>> import smbus > >>> b = smbus.SMBus(2) > >>> print(b.read_word_data(0x18,0x06)) > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > IOError: [Errno 121] Remote I/O error > > > python3 > >>> import smbus > >>> b = smbus.SMBus(2) > >>> print(b.read_word_data(0x18,0x06)) > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > OSError: [Errno 121] Remote I/O error > > The only thing unique about this PB is that I am using a USB-2 to Ethernet > interface for SSH access on USB1 port. Driver is already included in the > kernel/img. > Should not have any impact on I2C operation. I2C is not used by the > Ethernet, just USB. > ---------------------------------------------------------------- > -- 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]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/dc0b1677-8563-4dca-be64-7c11c1d866c1%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
