I've searched for a thread that tells you exactly how to mod the CAS but I can't find anything... Can somebody get me a link that will tell me what's goin on? I know I'm supposed to cut two opposing teeth on it, but a little more description would be helpful, like ANY two opposing teeth? Am i just notching them or removing them? etc..... Thanks ahead of time!

 

You don't have to cut any teeth at all if you build a circuit to condition the signal from the G sensor.

For the 2 teeth, you should install the CAS in the middle of its travel, and position it on a tooth, then cut the one 3 teeth back (to the left of the sensor) and the tooth opposite that if you want to mod the CAS.

I recommend against modding the CAS, as the missing tooth setup is more prone to noise issues.

Ken

 

awesome, just what i needed to know, thanks!

 

Okay, I've decided to take you advice and NOT mod the CAS. I already have a daughterboard sitting here with dual lm815 circuits wired up. It's got some other nice features on there too, but all I really need outta that would be the boost control, and I've got a profec-B to do that job. The only problem is it's not wired to the main board. It's just sitting here outside of the case.

How do I condition the lm815 circuits to read the CAS?
How do I get the daughterboard wired up to mainboard so that it can read the CAS?

Sorry if these are some elementary questions, I realize I'm in over my head, but this is what I've got so I need to learn! I appreciate any help I can get, thanks in advance!

oh yea, I CAN read a wiring diagram, I guess I just someone to show me one.... thanks again!

 

Depends which board you are using V2.2 or the blue V3.0. check the sticky FAQ post #6.You will see the LM1815 circuit diagrams and the VR hookup diagrams for both boards, the ignition outputs diagram is for the V3.0 board only. Unfortunetly the pics all disappeared, so it is kind of frustrating going through that. Post some info on what you are using board wise and which daughterboard and version. If you are using a V2.2 board ,you are going to need to add another connector on the case somewhere,as there aren't enough free pins on the main connector to add the VR inputs and ignition outputs, The V3.0 is much easier to make a neat install.

 

It's a V2.2, the main board is already set up to do the ignition, it has been wired up per the FAQ and is ready to go, just have to load up all the firmware / perimeters / maps.

Okay, for the CAS Inputs I'm looking at LM1815 circuit 2, that one is on the daughterboard yes? So I've got to run that to the MS1 board, and then from U1-11 to another connector, then from the additonal connector to the plug at the wiring harness then?

That is messy! Guess I need to get another case for it then too....

 

For the VR conditioners-LM1815's(connection from the extra board to the Megasquirt board)

For a unmodified CAS(for a modified CAS where two opposing teeth have been removed from the Ne-24 tooth wheel,you only need VR-1 connected)

1. VR-1 (aka:"Ne"-24 tooth wheel on CAS) goes from the appropriate connection from the extra board(depends on the version,and you should have info-if not post which one it is) to "U4-pin6" on the V2.2 MS1 board.
2. VR-2(aka:"G"-2 tooth wheel on CAS) goes from appropriate connection of the extra board through a 1K ohm resistor to "U1-pin11" on the V2.2 MS1 board. You have to add a 1K ohm resistor on the this line connection only.


You now need some sort of a connector with at least 4 pins that bring in the CAS signal lines,i.e. "Ne-",Ne+","G-","G+" to the appropriate connections on the extra board. Depending on how you place the extra board,most usually put them topside of the MS board from what I see and run a connector out the laptop connection side. You can use another DB-9 or a DB-15 connector depending on how many features you are planning to use with the extra board ,but you don't have much space above the LED's. The other option is to place the board underneath the MS board. This a little neater for a V2.2 board as the top side of the board is free if you want to later add a MS2 processor and you have more room for a connector below the MS board on the laptop connection side.

Here is the link for the MS1-extra manual. Good reading and most all the info needed along with the FAQ sticky.
http://www.msextra.com/manuals/MS_Ex...nual_Index.htm

 

thanks for walking me through it! I'll post with some updates once i get some time to get to work on it!