Sorry for the double post, but I just really want to make sure I am not fighting dodgy hardware before I go and pull all the tools I need from work to figure out my problem:
from my project thread:
I took a look at the VR sensor signals during cranking.
- noise: ~100mV pk-pk Secondary, ~50mV pk-pk Primary
- signals: ~1.5V pk-pk
Confirmed 12 primary, 1 secondary pulse. The issue is the noise, generating false triggers on the secondary.
Improvement #1:
- I changed the 0R at R182 with a 100K (is 150K on primary VR circuit)
- added the solder blob to pull up pin 5 of the LM1815 to Vcc
grounded the sensor -ve directly next to the LM1815's
- this got the car running, at 500-690rpm, trigger logs show all good from cranking up to this speed
New Problem:
I now cannot bring the engine up past this speed, it starts generating false secondary triggers, the noise gets worse with RPM.
I am concerned that my board has issues, as it is was supplied in October 2006, could this be a problem:
http://www.vems.hu/wiki/index.php?page=GenBoard%2FManual%2FInputTriggerHardWare%2FReplaceCI will try this anyway, and with attempt to put further filtering on the input - are there any recommendations on this before I calculate a suitable RC filter?
trigger log here shows the false sec triggers:
http://www.mediafire.com/?4x2w8d0c963dyet