Adopting remote footswitch for use.

[msi]

I have a line6 footswitch that I would like to use to send midi out using the midibox.  I'm having an issue though because I don't understand how they are handling the 74hc595 chips.  It appears to me that the serial data, latch and clock are all coming in on the same pin.  The footboard is designed to connect to a Pod amp simulator using an RJ45 cable.  Two pins are used for power, two for ground.  One pin is used for switches, and two for foot pedals.  The last pin is for the leds and 74hc595's.  

 

Here is the schematic of the part.

[TK.]

This seems to be a very tricky circuit.

 

Actually two pins are involved:

pin 7 controls the latch (=RCLK in MIDIbox terminology)

Pin 8 serves clock and data.

The clock will be delayed by several nS - I guess that depending on the pulse modulation either a 1 or 0 will be shifted into the register.

 

E.g.:

   _____
___|    |___

 

will shift a 1, and

    _
___| |______

 

could shift a 0?

 

This is only an assumption, and the appr. software changes into MIOS could only be developed by a real expert!

 

Best Regards, Thorsten.