I use a picoscope 4227.
When I send a TTL signal on the EXT input with a 0.5V high level to begin analog signal acquisition on the A or B input, it doesn't work. If the high level value is higher (1 to 4 Volts for example), the trigger works well.
I suppose that the problem comes from the trigger threshold (16-bit counts) value of trigger settings sent to ps4000SetSimpleTrigger function.
I tried different values because I didn't find any information in the datasheet. Above value 480 the trigger doesn't works at all. For 100 or 200 it works from time to time.
Moreover after reading the post of LESICA on the forum, I wonder if I have the same problem that LESICA.
Should I use the modified driver that you mention ?