While v2.2 was running the engine (fuel only), we took a PC scope and a v3.1 (with Alubos and lotsof wires) to check the signals from the distributor. The signals were as we thought:

* GND

* 12V

* 5V trigger for every event (4 camtooth: coil-type if you like)

* 5V trigger 1 per engine cycle (1 camtooth)

[a scope snapshot]

notes:

* 1/10 probe was used, so grid is 1V (not 0.1V)

* the scope captured the very last tooth for the yellow signal (the 1 camtooth HALLsignal) when the probe was disconnected. The 4 tooth signal continued for a while. During normal operation the frequency of the green was exactly 4* times that of yellow.

On the picture, green duty is about (12msec / 32 msec)

When RPM was about 1500,

* the green duty was 7.5 msec and period 20 msec

* the yellow period was 80 msec

We attached the v3.1 LM1815 input (through a 10uF 35V 1210 cap, that was on its place on the bottom side of board) to the 4-tooth signal, and read the correct RPM value (after enabling the primary_trigger).