On Fri, Nov 1, 2013 at 12:09 AM, Joshua Datko <jbda...@gmail.com> wrote: > Nevemind, that may be unrelated. I just rebooted and my device enumerated > fine. I think what's confusing (me) is the I2C2 by the SRM (P9_19/20) shoes > up as I2C1...
Yeah, this is a really confusing (well-known) issue where the latest Linux kernels assign the bus names in order of them being enumerated, despite whatever hardware name is given to them. So, I2C0, enumerated first, becomes, i2c0 and I2C2, enumerated second, becomes i2c1. If you then enumerate I2C1, you'll get an i2c2. Kinda confusing, got to give you that. > > some output: > > ebian@arm:~$ ls -l /sys/bus/i2c/devices/i2c-* > lrwxrwxrwx 1 root root 0 Nov 1 04:02 /sys/bus/i2c/devices/i2c-0 -> > ../../../devices/ocp.2/44e0b000.i2c/i2c-0 > lrwxrwxrwx 1 root root 0 Nov 1 04:02 /sys/bus/i2c/devices/i2c-1 -> > ../../../devices/ocp.2/4819c000.i2c/i2c-1 > debian@arm:~$ su > Password: > root@arm:/home/debian# i2cdetect -r 1 > WARNING! This program can confuse your I2C bus, cause data loss and worse! > I will probe file /dev/i2c-1 using read byte commands. > I will probe address range 0x03-0x77. > Continue? [Y/n] Y > 0 1 2 3 4 5 6 7 8 9 a b c d e f > 00: -- -- -- -- -- -- -- -- -- -- -- -- -- > 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > 40: -- -- -- -- -- -- -- -- 48 -- -- -- -- -- -- -- > 50: -- -- -- -- UU UU UU UU -- -- -- -- -- -- -- -- > 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > 70: -- -- -- -- -- -- -- -- I need hints on how the MPU6050 should be wired up or assume that I've got a bad device. I can probably try hooking it up to something else. > > > > On Thursday, October 31, 2013 9:57:08 PM UTC-6, Joshua Datko wrote: >> >> So I've been struggling with I2C. Somebody on this list gave me the tip >> to do: >> >> echo BB-I2C1 > /sys/devices/bone_capemgr.????/slots >> >> which enables the third I2C bus and my device then was visible via >> i2cdetect -y -r 1 on pins P9_19 and P9_20. Although, after doing that, >> you'll have an i2c1 and a i2c2 bus, so might want to check both. But, I'm >> not quite sure why this works :) >> >> In my case, I don't think there is device tree entry for the device I'm >> using, so I was planning on interacting with it over raw I2C. >> >> Hope this helps, >> >> Josh >> >> >> On Thursday, October 31, 2013 2:32:46 PM UTC-6, Jason Kridner wrote: >>> >>> On Tue, Oct 29, 2013 at 2:19 PM, Jason Kridner <jkri...@beagleboard.org> >>> wrote: >>> > >>> > On Thu, Oct 17, 2013 at 6:12 PM, <clarkbr...@gmail.com> wrote: >>> > > AIW: >>> > > I went back thru the adafruit library and didn't find anything >>> > > specific on >>> > > I2C, although it is listed as a topic. I have been looking at their >>> > > github >>> > > adafruit-beaglebone-io-python library. I also found and looked thru >>> > > PyBBIO. >>> > > Even tho I'm not using Python, I can see the access mechanisms that >>> > > they >>> > > use. >>> > > I can use the MPU6050 device ok enough just reading via >>> > > /dev/i2c/i2c-x, but >>> > > that is too slow. >>> > > I'm trying to figure out how to invoke and use the inv-mpu6050 driver >>> > > and >>> > > adafruit doesn't use that. >>> > > Thx -- Clark >>> > > >>> > > On Thursday, October 17, 2013 9:47:44 AM UTC-7, AIW wrote: >>> > >> >>> > >> Some good info on I2C tools at http://www.acmesystems.it/i2c. >>> > >> >>> > >> Python and the adafruit BBIO I2C library makes it very easy to use >>> > >> I2C on >>> > >> Beaglebone Black as well. Python import smbus is fairly easy to use >>> > >> too. >>> > >> Some examples of use is available in the code I provide for my radio >>> > >> project >>> > >> here....www.aiwindustries.com. >>> > >> >>> > >> Not trying to sell the product, but I know that the I2C function was >>> > >> giving me some issues so I'm just trying to help the community. >>> > >> Python code >>> > >> is available to download and look at usage so feel free. >>> > >> >>> > >> On Tuesday, October 15, 2013 5:02:59 PM UTC-5, clarkbr...@gmail.com >>> > >> wrote: >>> > >>> >>> > >>> We are using the Invensense MPU6050 IMU on I2C with Beaglebone >>> > >>> Black >>> > >>> (Angstrom 3.8.13). We can use I2C-tools and file I/O thru /dev/i2c >>> > >>> but the >>> > >>> read speed is disappointingly slow. We only read the 3x gyros and >>> > >>> 3x accels >>> > >>> (each one byte at a time plus the 2 byte temperature reading) and >>> > >>> it takes >>> > >>> ~2msecs. My estimate of the I2C bus cycles for a block read >>> > >>> suggests this >>> > >>> should take ~160 bus cycles or .38msec on a 400MHz I2C bus. >>> > >>> > You are running at 400kHz, not 400MHz, right? I2C doesn't do 400MHz. >>> > >>> > >>> >>> > >>> The distribution includes the Invensense driver inv-mpu6050.ko but >>> > >>> there >>> > >>> is no indication that reading through /dev/i2c invokes it. This is >>> > >>> a very >>> > >>> popular IMU and Invensense widely distributes the driver over many >>> > >>> Linux >>> > >>> platforms. The driver source includes “successful installation >>> > >>> will create >>> > >>> two directories under /sys/bus/iio/devices” and lists the files >>> > >>> there (aka >>> > >>> functions). I can never get these to show up. >>> > >>> >>> > >>> I can “insmod >>> > >>> >>> > >>> /lib/modules/3.8.13/kernel/drivers/iio/imu/inv_mpu6050/inv-mpu6050.ko” >>> > >>> and >>> > >>> “echo inv-mpu6050 0x68 > /sys/class/i2c-adapter/i2c-1/new_device”. >>> > >>> This >>> > >>> causes a new directory named 1-0068 to show in >>> > >>> /sys/class/i2c-adapter/i2c-1with entries like name and modalias but >>> > >>> no >>> > >>> functions. It never shows in /sys/bus/iio/devices. >>> > >>> > I don't have an MPU6050, but I just ordered a couple on express >>> > overnight from Sparkfun. >>> >>> I bought https://www.sparkfun.com/products/11028 and played with it >>> briefly before being distracted and again today, but I don't >>> understand why I'm not able to get it to reply to me. >>> >>> I have the following connections: >>> VCC: P9_4 (VDD_3V3) >>> GNC: P9_1 (GND) >>> INT: P9_11 (GPIO) >>> FSYNC: - >>> SCL: P9_19 (I2C2_SCL) >>> SDA: P9_20 (I2C2_SDA) >>> VIO: P9_3 (VDD_3V3) >>> CLK: - >>> ASCL: - >>> ASDA: - >>> >>> I then perform: >>> >>> root@beaglebone:~# i2cdetect -y -r 1 >>> 0 1 2 3 4 5 6 7 8 9 a b c d e f >>> 00: -- -- -- -- -- -- -- -- -- -- -- -- -- >>> 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- >>> 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- >>> 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- >>> 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- >>> 50: -- -- -- -- UU UU UU UU -- -- -- -- -- -- -- -- >>> 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- >>> 70: -- -- -- -- -- -- -- -- >>> >>> Very confused why it doesn't show up. >>> >>> Since you have it responding to you, how do you have it wired? >>> >>> > >>> > Here's the behavior I'm seeing without the board connected: >>> > >>> > root@beaglebone:/lib/modules/3.8.13/kernel/drivers/iio/imu/inv_mpu6050# >>> > ls >>> > inv-mpu6050.ko >>> > root@beaglebone:/lib/modules/3.8.13/kernel/drivers/iio/imu/inv_mpu6050# >>> > dmesg | tail -1 >>> > [ 2992.799594] i2c i2c-1: new_device: Instantiated device inv-mpu6050 >>> > at 0x68 >>> > root@beaglebone:/lib/modules/3.8.13/kernel/drivers/iio/imu/inv_mpu6050# >>> > lsmod >>> > Module Size Used by >>> > ip_tables 8294 0 >>> > x_tables 15072 1 ip_tables >>> > g_multi 55905 2 >>> > libcomposite 15228 1 g_multi >>> > rfcomm 25106 0 >>> > ircomm_tty 14503 0 >>> > ircomm 8846 1 ircomm_tty >>> > irda 89974 2 ircomm_tty,ircomm >>> > ipv6 229989 14 >>> > hidp 10112 0 >>> > bluetooth 146100 4 hidp,rfcomm >>> > rfkill 16510 2 bluetooth >>> > autofs4 17432 2 >>> > >>> > I looked for the installed device: >>> > >>> > root@beaglebone:/lib/modules/3.8.13/kernel/drivers/iio/imu/inv_mpu6050# >>> > cat /sys/bus/iio/devices/iio*/name >>> > tiadc >>> > root@beaglebone:/lib/modules/3.8.13/kernel/drivers/iio/imu/inv_mpu6050# >>> > ls /sys/bus/iio/devices/iio* -d >>> > /sys/bus/iio/devices/iio:device0 >>> > >>> > It is clearly missing per the documentation >>> > >>> > (https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-bus-iio-mpu6050) >>> > that says there should be a sysfs entry there. >>> > >>> > Just in case I could get it to show up, I did try manually doing a >>> > modprobe. >>> > >>> > root@beaglebone:/lib/modules/3.8.13/kernel/drivers/iio/imu/inv_mpu6050# >>> > modprobe inv-mpu6050 >>> > root@beaglebone:/lib/modules/3.8.13/kernel/drivers/iio/imu/inv_mpu6050# >>> > lsmod >>> > Module Size Used by >>> > inv_mpu6050 7190 0 >>> > ip_tables 8294 0 >>> > x_tables 15072 1 ip_tables >>> > g_multi 55905 2 >>> > libcomposite 15228 1 g_multi >>> > rfcomm 25106 0 >>> > ircomm_tty 14503 0 >>> > ircomm 8846 1 ircomm_tty >>> > irda 89974 2 ircomm_tty,ircomm >>> > ipv6 229989 14 >>> > hidp 10112 0 >>> > bluetooth 146100 4 hidp,rfcomm >>> > rfkill 16510 2 bluetooth >>> > autofs4 17432 2 >>> > root@beaglebone:/lib/modules/3.8.13/kernel/drivers/iio/imu/inv_mpu6050# >>> > ls /sys/bus/iio/devices/iio* -d >>> > /sys/bus/iio/devices/iio:device0 >>> > >>> > Of course, this all makes perfect sense since the driver should exit >>> > upon failing the 'probe': >>> > >>> > https://github.com/beagleboard/linux/blob/3.8/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c#L658 >>> > >>> > I'd have to look up how to turn on more debugging statements. I tried >>> > the hints at http://elinux.org/Debugging_by_printing, but I'm >>> > surprised the 'dmesg' log didn't show any extra errors. >>> > >>> > >>> > >>> >>> > >>> What constitutes “successful installation”? >>> > >>> >>> > >>> What else is needed to get the inv-mpu6050 to expose functions in >>> > >>> /sys/bus/iio/devices like the driver sources says? >>> > >>> > I don't think anything else should be required. To build the kernel >>> > properly, there are a few things that need to be enabled >>> > >>> > (https://github.com/beagleboard/linux/blob/3.8/drivers/iio/imu/inv_mpu6050/Kconfig): >>> > >>> > INV_MPU6050_IIO, I2C, SYSFS, IIO_BUFFER, IIO_TRIGGERED_BUFFER >>> > >>> > And they are all there: >>> > https://github.com/beagleboard/kernel/blob/3.8/configs/beaglebone#L3676 >>> > >>> > >>> >>> > >>> Beaglebone Black uses bone_capemgr for exposing driver functions >>> > >>> for many >>> > >>> devices. “echo inv-mpu6050 0x68 > >>> > >>> /sys/devices/bone_capmgr.9/slots” raises >>> > >>> the gripe “write error: no such file or directory”. (I can >>> > >>> successfully >>> > >>> load the am33xx_pwm driver this way.) Is this because there is no >>> > >>> matching >>> > >>> DT fragment in /lib/firmware? >>> > >>> > Yes. >>> > >>> > >>> Is the inv-mpu6050 driver supposed to be >>> > >>> invoked thru cape manager? >>> > >>> > No, because the I2C bus software provides another mechanism. I believe >>> > you could create a DT fragment, but I think it is pointless. >>> > >>> > >>> >>> > >>> Then, most importantly, if I did read and write through the /sys >>> > >>> tree >>> > >>> using the Invensense driver would it be faster than /dev/i2c? >>> > >>> Help on sorting this out would be much appreciated. >>> > >>> > Yes, because the driver running in kernel mode is going to be higher >>> > performance than your pokes from userspace. >>> > >>> > > >>> > > -- >>> > > 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...@googlegroups.com. >>> > > 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 beagleboard+unsubscr...@googlegroups.com. > 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 beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
