I used to work with a project that uses tiny2313 and I2C DTMF encoder PCD3312. I had no problem with that, until I decide to combine it with I2C LCD (David help me a lot in the past) with those libraries. Please, notice that I2C LCD libraries work perfect, alone. When I combine i2c.h with lcd_i2c.h, LCD work fine but PCD3312 sends music tones instead of DTMF.
(PCD3312 and PCF8574 have different addresses).
Any ideas ?
Thank You and happy new year !