_camera.i2c_read() and _camera.i2c_write()

[josuah]

This patch should allow sending custom I2C commands to the camera for the various purposes:

• debugging a sensor
• enabling RGB mode
• enabling other camera modes
• testing/developing new/experimental features safely without requiring a new firmware upgrade
• allow to ship more features as python files, from either users or Brilliant.

These do not need to be documented or even work now: this is the point of the patch: allow turning on features already present in the device, simply by documenting them.
As long as they do not damage is done by using these functions, they could be shipped.
The I2C address is limited to the camera, which avoids any risk of communicating with any other device.]

Usage:

import _camera
print(_camera.i2c_read(0x1234))
_camera.i2c_write(0x1234, 0x56)

The mask is hard-coded to 0xFF, which can be adjusted by calling i2c_read, masking, then calling i2c_write.

I did not test this all yet.

[kodjima33]

@siliconwitch @josuah huge thanks for working on this PR! We really need better camera quality and can't move forward without it

[josuah]

need better camera quality

The higher the camera resolution, the longer the transfer time, so this would let you range the exact amount by experimenting.