Comments on the State of the Union MicroSquirt info

[Bruce Bowling]

I _have_ held a Microsquirt and can testify that there is physical space in the case to mount more stuff. But, this was the first revision single channel version. Bruce gave us the answer though - there isn't board space to fit the map sensor.

James

I wish there was room on the PCB direct for a MAP sensor, with the addition of the extra VR input and VB921 there is no room left anywhere - here is a image of the latest OrCAD layout showing what is left remaining on the PCB real estate:



Its easy to see the board is pretty much consumed with parts. Its to be expected when taking a 4 x 6 board and condensing to a 2.5 x 3.5". But other than the ampseal, the board is 100% surface mount, with all parts on the top side. Having all of the components on one side helps significantly in assembly costs, only one IR reflow operation needs to occur, and the ampseal can be wave-soldered afterwards. If there were SMD parts on both sides then the board could not be wave-soldered at all; the connector would have to be hand-soldered in place at the assembly house after two separate reflow operations (top and bottom). Every operation adds assembly cost to the board, especially hand operations.

The case does has some headroom in it so it is possible to put in another PCB with a MAP sensor and other circuits.

- Bruce

[mrbell]

So... did I miss it or does anyone know how the betatesting is going? or if it has even started?
I've been quietly waiting for someone to post some results, but now I'm getting antsy... sorry.

[Bernard Fife]

mrbell,

Beta testing hasn't started, the changes to incorporate the second ignition driver resulted in the delay. Beta testing should begin shortly, I imagine.

Lance.

[newtyres1]

I'm looking forward to the release too, mainly because I feel it will be a significant achievement in the ongoing development of MS. I think just as many or more will be installed on 4 cyl cars as will go on m'cycles, off-road vehicles etc. I fully agree with an external MAP sensor and the whole project as it stands.
Ian.

[mrbell]

Agreed. External map, on this project, is the way to go.

[83quattro]

There aren't three ignition drivers, so Coil On Plug is out of the question. With two ignition drivers in a waste spark setup, you would need two cylinders to fire at the same time; possible with your 180° crank, not 120° unfortunately.

If you use a cam sensor with a 3 hole rotor for a 3-pot, or 2x3 holes and a twin sensor for a 6-pot, and a second box vith 3 or 6 coil drivers, you should be able to run a wasted spark-setup with 3 coils firing at the same time.

I think....

O.J.