I made ion sensor.
100-400V regulated switcher(most part from atx power supply)
and this senzor
http://vvnet.fi/ville/ion/DIY-Ion-Sensing-2.pdf
And i did same measurement(290 and 330V).
2000rpm spark 22 BTDC
idle
Plan is use AT91SAM7S128 for ppp calculation (and maby knock detection), connect to vems via(can, spi or ?)
Any suggestion?