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*<https://github.com/adafruit/adafruit-beaglebone-io-python> library. I also found and looked thru *PyBBIO* <https://github.com/adafruit/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, [email protected] 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. >> >> 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. >> >> 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? >> >> 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? Is the inv-mpu6050 driver >> supposed to be invoked thru cape manager? >> 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. >> > -- 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.
