inconsistency between silk screen and docs

For engine experimenters, the MicroSquirt® PCB is offered in a module format with enhanced capabilities to be plugged into other boards. This is the place to discuss the MicroSquirt Module.
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JustinHoMi
MegaSquirt Newbie
Posts: 12
Joined: Thu Sep 08, 2005 8:53 pm

inconsistency between silk screen and docs

Post by JustinHoMi »

I just noticed that there are some inconsistencies between pin assignments on the silk screen on the microsquirt module (v2.2M) and the documention at http://www.microsquirt.info.

Printed on the module:
Pin31 - Serial Ground
Pin33 - Sensor Ground
Pin35..43,49 - Power Ground
Pin44,46 - IGN2 Out
Pin48,50 - IGN1 Out

In docs:
Pin31 - Sensor Ground
Pin33..43,49 - Power Ground
Pin44,46 - IGN1 Out
Pin48,50 - IGN2 Out


Which is correct?

Also, the pin assignments for Pins 45 and 47 were omitted. Are these also Power Grounds?

Edit: Also, are the coordinates depicted in the "Mounting Locations for Module" graphic correct (http://www.microsquirtmodule.com/indexright.html)? J1 Header appears to be higher (y) than specified. The weird thing is that I created a CAD part for this several months ago, and went back to double-check my work today. All of the x,y coordinates were different than the diagram. Was this diagram changed? I think that the old coordinates better reflect the actual layout of the board.
Bernard Fife
Super Squirter
Posts: 1009
Joined: Mon Feb 16, 2004 3:15 pm

Re: inconsistency between silk screen and docs

Post by Bernard Fife »

R,

The module documents are at: http://www.microsquirtmodule.com/index.htm

The best info is in the schematics posted in a link on that page. The schematics confirm what you have said, and the docs will be updated very shortly. BTW, odd numbered pins between 31 and 49 are just common grounds -they all are connected on the board, so the assignments are interchangeable.

I don't know if the mounting coordinates have changed, but I will find out.

Lance.
JustinHoMi
MegaSquirt Newbie
Posts: 12
Joined: Thu Sep 08, 2005 8:53 pm

Re: inconsistency between silk screen and docs

Post by JustinHoMi »

Thanks. That is the same page that I'm looking at. The link I provided is just the right frame on that page.

Bruce gave a talk at a MegaMeet in 2008 that discussed the importance of separating signal and power grounds on the MS-I v3.0 boards. There are two major ground planes on that board which keep the signal and power grounds separate. They are eventually tied together at the connector, but it is still important to run separate signal and power ground wires using the appropriate pins. If that is also the case with the Microquirt Module, then I'd like to make sure that the grounds make their way to the appropriate ground wires on the harness.

That leads me to another question... if that is the case, then are pins 3 and 5 on J1 sensor grounds or power grounds?
JustinHoMi
MegaSquirt Newbie
Posts: 12
Joined: Thu Sep 08, 2005 8:53 pm

Re: inconsistency between silk screen and docs

Post by JustinHoMi »

Any update on the board dimensions or the J1 grounds?
Bernard Fife
Super Squirter
Posts: 1009
Joined: Mon Feb 16, 2004 3:15 pm

Re: inconsistency between silk screen and docs

Post by Bernard Fife »

JHM,

I have been traveling this week, but will try to find out today.

Lance.
JustinHoMi
MegaSquirt Newbie
Posts: 12
Joined: Thu Sep 08, 2005 8:53 pm

Re: inconsistency between silk screen and docs

Post by JustinHoMi »

Haha, that's funny. JHM are my real initials. It was 16 years ago... and I was going through the list trying to find an available name on AOL. Justin, JustinM, JustinHM, JustinHoMi (I laughed and went with it).

Thanks for looking into this for me.
Bernard Fife
Super Squirter
Posts: 1009
Joined: Mon Feb 16, 2004 3:15 pm

Re: inconsistency between silk screen and docs

Post by Bernard Fife »

Justin,

Here are the measurements I get directly off the bottom side of a module:
module_mount.gif
Below is the old illustration of the top side of the module in the docs:
mod_mounting.GIF
It all looks withing a hundredth of an inch of the original (which is close considering the inaccuracy of measuring the hole's centers exactly). However, my board is pretty old (v2.1M), and the placement may have changed with later versions.

I will contact Bruce and ask him to comment on this thread.

Lance.
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