MembersPage/EricN/Trigger/Optical (2006-04-08 19:36:30)

Optical primary trigger page for MembersPage/EricN/Trigger

Planning on using 12-1 trigger wheel mounted in the distributer.

Trying an optical trigger now, followed instructions for Hall sensor on primary trigger as per manual. Seems to trigger properly.

Picked up an OPB804 optical switch. Built it into this little circuit that I found on the internet

opticaltrigger.JPG

Changed the 1k resister to 100ohm, voltage at led is 1.25v to gnd (normal for an infrared LED). Using pullup on vems

Optical trigger no better, pc signal generater the same, fuel relay cutting out at any rpm, worse at low.

Traced trigger signal right to pin 29 on atmega128, signal looks identical on scope when compare to signal at the wire, suspect problem is in config, want to start with a clean config.

publish:

The first B1 is the primary trigger pulsecount. It increments from B1=0317 to B1=04BF so the trigger signal reaches the processor. Maybe some noise also reaches, but it's also possible that something loosely related kicks in (eg. noise through GND when you switch outputs? Check GND and GND5 connections!). MegaTune log is next step to investigate this further.

After RPM:0498, RPM goes back to RPM:0000. In this time, B2=14C1 (handler2k counter, which increments every 1024 usec) goes more than it should in a second: B2=2BA4 (5859 instead of appr +977, that is appr 6 seconds intead of 1) => so serial comm cuts out for 5 seconds ? What's going on there ? Start to document the basic things, eg. firmware version. Did you try upgrade to a recent release or 1.0.38 ?

I dont know how to interpret that but I can tell you the fuel pump relay cut out alot, I bet 10 times or more.