Right, but I thought I don't need a third wire because I using an Interrupt. So each time the ISR is called, its something like the next clock cycle. 
I would try the shiftOut() and a third line 
Yes, I read the reference, but not complete, only these functions I needed in a sketch or which I understand at reading (I'm not from England or USA 
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Some times I need new thoughts to move forward. I watched a few videos today about SPI, IĀ²C and UART, maybe it will help me to understand how I can get my sketch running
I would try it another way.
Thanks