Getting stable midi-clock out of Ableton can be difficult. Buffersize and latency have a negative effect on the stability of the clock-signals –> the time between these clock signals varies (too much), with an unintended fluctuating tempo as a result. A solution (like the ER-M midiclock) is to take an audiopulse from the DAW and convert this to midiclock. The audio output is several factors more stable than the native midiclock. Problem is that this ER-M midiclock is quite expensive. The concept seems like a pretty good idea though.
So, how to approach this? How to convert an audio-pulse to midiclock?
Enter the arduino and some coding. Basically it comes down to this: send an audio-pulse 96 times per bar out of your audio-interface. Connect this to a processor like an Arduino, and figure out when the signal turns high, and when it turns low. Convert this to midi-clock, et voila: a stable clock which you can use to run external equipment with really stable clock.
For not very much money a stable midi-clock, much cheaper than
For code see github: https://github.com/albertsikkema/arduino_audio_pulse_to_midi_clock