No problem im hassling you with too many questions anyway..
If i run anything else that has the default 18 and 19 as the i2c pins its all good and runs fine. Its only the smartmatrix code that appears to not work..
If i remark out as below the core_pin lines in the matrix clock example ( which i assumed would just default the teensy back to 18 and 19 for i2c) the code compiles but the teensy does not run.. It would usually first display SET TIME on the panel and then display the time. when the core_pin lines are remarked out not even the SET TIME is displayed and nothing on the serial monitor either..
//CORE_PIN16_CONFIG = (PORT_PCR_MUX(2) | PORT_PCR_PE | PORT_PCR_PS);
//CORE_PIN17_CONFIG = (PORT_PCR_MUX(2) | PORT_PCR_PE | PORT_PCR_PS);
I tried this on both the teensy 3.2 and teensy 3.6 both with and without the shield but both lock up when the code runs..