This is not supported by uniPulse at the moment. The main reason this was not implemented in the first place: When producing a pulse at start and at stop, you will have to manually set the machine to the correct state at the beginning. And once you press start, you will be out of sync.
So finding the correct point start/stop is a much better solution. Usually there is a way of tapping into the circuit behind the start/stop flip/flop.
Luckily the UniPulse can create multiple simultaneous clocks with adjustable phase, so we don’t have to build an additional inverter. More about this later.
I see how this can be misleading. What is meant by this is that the phase of the clock outputs can be shifted by 180° (aka inverted). So you can generate the inverted clock signal as well without needing an additional inverter circuit.
Here is what I think should work to control the clock on the FR6. I can not test this, because I don’t have one:
The start button on an FR6M is momentary and is latched electronically.
Looking at the schematics I have, I get the opposite impression: There is no latch at all, just a (latching) start stop switch.
When the reset line is pulled to ground the machine is is stop mode, otherwise it runs.
Here is what I came up with:
To control start stop, you need to connect a general purpose NPN transistor as shown. The base is connected to uniPulse D3. D3 is configured as start/stop with inverted polarity.
Clock is injected at the bases of Q102 and Q103. The 1k resistors here are to protect the digital outputs of the uniPulse, but should be low enough to override the signals from the existing clock. The 1k resistors are then connected to D0 and D1 via a 2-way switch. The switch is used to select between internal and midi clock.
It would fantastic if you could very this and post pictures of these points on the boards themselves, so other can benefit from this info.
Thanks a lot!