2 questions that will help me add a few of my own 'features':
1. How many times a second is the MJ happy to switch maps using the option input, and does it mind doing so under full throttle and high rpms?
2. What do the user outs do when they're not 'on' (i.e. low)? Do they go to +5v or float? If I tie 2 together to catch a range (e.g. #1 goes low <500, #2 goes low >3000) will bad things happen? I ask because it would be nice to have the first shift light come on while cranking and go out until it's needed at say 4k rpm. Will I need to put diodes inline to do this?
Option switching and user outs
Moderators: JeffC, rdoherty, stieg, brentp
There are no specific restrictions in place for changing maps- it does pause controller activity while it switches between MAPs (copying data from Flash to RAM based on the MAP selected).
During this time the EDIS module may not receive a signal back on a PIP ignition event- and this is largely determined by RPM since the memory copying time is fixed and RPM is variable. However, this is not a problem since the EDIS module does not require a SAW pulse on every ignition event. I suppose if the maps were switched frequently enough, the prolonged absence of a SAW pulse would cause the EDIS module to go to 'limp home' mode of 10 degrees BTDC, until it received the next SAW pulse.
However, as mentioned in the other post, you may have a cleaner solution by modifying the existing firmware to achieve your goals- specifically why I've made it available to the community.
The user defined outputs are driven by an open collector transistor array. See the ULN2003 datasheet for details.
During this time the EDIS module may not receive a signal back on a PIP ignition event- and this is largely determined by RPM since the memory copying time is fixed and RPM is variable. However, this is not a problem since the EDIS module does not require a SAW pulse on every ignition event. I suppose if the maps were switched frequently enough, the prolonged absence of a SAW pulse would cause the EDIS module to go to 'limp home' mode of 10 degrees BTDC, until it received the next SAW pulse.
However, as mentioned in the other post, you may have a cleaner solution by modifying the existing firmware to achieve your goals- specifically why I've made it available to the community.
The user defined outputs are driven by an open collector transistor array. See the ULN2003 datasheet for details.
Thanks again!
Any idea roughly how long it pauses for? I'm still not sure whether it's best to go this route or to instead cut one out of every n spark events with the power mosfet circuit, where n can be decided based on amount of wheelspin. If it takes 1000's of clock cycles to switch maps then it'll probably end up in limp mode or by the time the low advance map becomes active you'll have gone sideways into a tree... If it's only a few then the first method should work, and with only very simple additions.
I'd like to keep the 2 systems seperate at first for easy debugging, but if I get anywhere I'll write up what worked and what didn't.
Any idea roughly how long it pauses for? I'm still not sure whether it's best to go this route or to instead cut one out of every n spark events with the power mosfet circuit, where n can be decided based on amount of wheelspin. If it takes 1000's of clock cycles to switch maps then it'll probably end up in limp mode or by the time the low advance map becomes active you'll have gone sideways into a tree... If it's only a few then the first method should work, and with only very simple additions.
I'd like to keep the 2 systems seperate at first for easy debugging, but if I get anywhere I'll write up what worked and what didn't.