Teensy Audio Board I2c_t3 issues

[StevenJUlbrich]

Hello,

I am trying to use a Teensy 3.2 with Audio Board as a i2c slave
when adding the i2c_t3 library it throws errors - conflicting declaration 'i2c_t3 Wire'
extern i2c_t3 Wire;

it is stated that replacing Wire.h with i2c_t3.h should be done in the Audio library.
./hardware/teensy/avr/libraries/Audio/control_sgtl5000.cpp
• ./hardware/teensy/avr/libraries/Audio/control_wm8731.cpp
• ./hardware/teensy/avr/libraries/Audio/control_cs4272.cpp
• ./hardware/teensy/avr/libraries/Audio/control_ak4558.cpp

What do you recommend?

[nox771]

You cannot use the standard Wire library and i2c_t3 at the same time. If you use i2c_t3 in your main program, then any library that uses the Wire library must also use it. So the straightforward way is to change Wire.h to i2c_t3.h in the Audio library (or any other library using Wire.h).

If you are using Arduino (Teensyduino) to build your program, then there is a more tricky method that leverages the build system such that you don't need to modify the libraries. It is described in these links:
https://forum.pjrc.com/threads/21680-New-I2C-library-for-Teensy3?p=79995&viewfull=1#post79995
https://forum.pjrc.com/threads/21680-New-I2C-library-for-Teensy3?p=80340&viewfull=1#post80340

[nuket]

One easy way to do this when using PlatformIO is to ignore the Wire library by setting lib_ignore in platformio.ini, for example:

[env:teensy35]
platform = teensy
board = teensy35
framework = arduino
lib_ignore = Wire

PlatformIO has some major advantages over the Arduino environment as it is, such as linting and autocomplete.