The notes here describe the operation of the two different versions of the 'Looper Stop' Interface.
(Click on the image at the top of this page to see a photo of a typical assembly, using a 'Ditto+' Looper with the Interface)...

That image shows the 3 connections to the power plug sockets:
• One 2.1mm power plug lead from the 9V DC power supply (center negative)
• One short link lead - fitted with a 2.1mm power plug at each end - to connect DC out from the interface, to the DC in socket on the Looper pedal.
• One 1.3mm power plug, fitted to the end of the lead fitted internally to the Ditto+ PCB....
• At the other end of the enclosure, an external 'normally closed' footswitch is plugged into the jack socket.
• Finally, an output jack plug is fitted to the 'audio out' jack of the 'Ditto+'

The photo shows the 'One Switch' variant...
The 'Two Switch' assembly is similar, but with the addition of a second 'normally closed' footswitch, and a jack plug fitted to the audio input of the Looper pedal.

One Switch Version:
This version of the Interface is intended for when the Looper is only being used to replay pre-recorded loops and backing tracks,not for creating new loops live, or for adding overdubs.
The single external footswitch fitted is used simply to start and stop the Looper with alternate single presses of the switch.
The Interface will generate alternating 'single' and 'double' short (c.50mS) pulses to achieve this. Holding the footswitch down for a longer time will not activate the erase function, for example.

If an empty location is selected by mistake, then pressing the footswitch will start the Looper in record mode. Nothing will be recorded - as there is no input jack fitted in this configuration - but the loop will record silence, until the footswitch is pressed once again to stop the device.
If the footswitch is pressed once again then that 'silent' loop will be replayed. As it is likely to only be few seconds long, then it can probably be left until it is more convenient to erase the track?
(The track can be erased by holding the switch on the Looper itself, as you would if the Interface was not fitted.)
It has been suggested that all unused tracks could have very short silent recordings added, to avoid accidently activating the record mode?
(Easy enough on the empty slots from a 9 slot Lekato Looper... Probably much more time consuming to fill all the empty slots from the the 99 locations available on a Ditto+ Looper!)

Two Switch Version:
This version is more appropriate where the Looper is used in its conventional mode, with new recording and overdubs available in real time.
The 'primary' external footswitch simply mimics the switch on the Looper itself. You can perform all the Looper functions with it - including the 'double tap' stop function.
The 'secondary' external switch serves only as a 'one tap' stop switch. It only functions when the unit has been activated by the primary switch. It will stop a running Looper with a single tap, but will not do anything further if pressed again, until the unit has been re-activated.

It is important to note that although the original switch on the Looper will still perform all its functions, it is unwise to use it when the Interface is connected. Although the Interface knows which of the external footswitchs have been pressed - and in what order - it has no way of knowing whether the 'onboard' Looper switch has been pressed or not.
To avoid any problems that may arise from an unexpected logic sequence, it may be advisable to physically inhibit the Looper switch itself, when this Interface is being used?