_i2CTransaction function failing leading to inability to use i2c bus

[ArthurAllshire]

I2C reading and writing does not work on the roboRIO. It seems like the fail to _i2CTransaction in i2CTransaction fails. Code: from wpilib import I2C

class BoschGyro():
    def __init__(self):
        self.gyro = I2C(I2C.Port.kMXP, 0x29)

    def exists(self):
        return self.gyro.addressOnly()

Fails on call to addressOnly() Error I am getting on the driver station:

File "/home/lvuser/py/robot.py", line 84, in teleopInit
    self.logger.info("Gyro: ", self.gyro.exists())
File "/home/lvuser/py/subsystems/bosch_gyro.py", line 8, in exists
    return self.gyro.addressOnly()
File "/usr/local/lib/python3.5/site-packages/wpilib/i2c.py", line 74, in addressOnly
    self.transaction([], 0)
File "/usr/local/lib/python3.5/site-packages/wpilib/i2c.py", line 63, in transaction
    dataToSend, receiveSize)
File "/usr/local/lib/python3.5/site-packages/hal/functions.py", line 402, in i2CTransaction
    rv = _i2CTransaction(port, device_address, send_buffer, send_size, recv_buffer, receive_size)
ctypes.ArgumentError: argument 5: <class 'TypeError'>: expected LP_c_ubyte instance instead of _ctypes.PyCArrayType

I'm just calling the function from teleopInit(), and it completely crashes the robot code.

[virtuald]

This problem is fixed in the latest master, I just haven't made a release yet (you should subscribe to the robotpy mailing list :) ).

Master also contains functionality that allows you to simulate i2c devices, check out https://github.com/robotpy/robotpy-wpilib/blob/master/wpilib/tests/test_i2c.py. I was hoping to add a simulator for one of the gyros as an example before making the release.

[ArthurAllshire]

@virtuald How would I go about installing the current master to the roborio or should we just wait until the next release?

Thanks for responding so quickly. Definitely signed up to the mailing list ;)

[virtuald]

See devtools/build_and_deploy.sh. I'm trying to get it out tonight (so.. maybe in the next 4 hours).

[virtuald]

Pushed 2016.1.0 to pypi. Added more stuff to the i2c/spi simulators, there will be an update of pyfrc to support some of it too.