On Tue, Oct 29, 2013 at 2:19 PM, Jason Kridner <jkrid...@beagleboard.org> wrote: > > On Thu, Oct 17, 2013 at 6:12 PM, <clarkbriggs...@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+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. 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