MicroSquirt.com read only forum (Jan.15,2018)

Hello,

Today I read this in this forum:

You need the controller, MegaSquirt (or MS-II) do not have a built-in WBO2 driver at this point.

I didn't know this!

So, If I plan to use a wide band O2 sensor, I MUST buy a WB controller, am I right?

However, the EGO input of MS II (pin 23 of DB37) supports a signal from 0 to 5 V, so MS II can "read" the signal from a WB EGO sensor but this signal is unusable(but viewable with megatune?)?

Am I right?

MS II can "read" the signal from a WB EGO sensor but this signal is unusable(but viewable with megatune?)?

Ludotech,

Not quite. The wideband sensor needs a controller to adjust it's equilibrium point. The amount of current required to achieve that equilibrium indicates the air/fuel ratio.

You need a controller to provide that current, and it has to provide the current while measuring and maintaining the equilibrium. So it is a fairly sophisticated circuit, and one that does not existing in MegaSquirt (or MS-II).

So you need a controller to:

a) drive the sensor to an ever-changing equilibrium, and
b) convert the current required to do that into a 0-5 Volt signal.

Without a controller, a wide band sensor is essentially just two narrow band sensors hooked together in the same case...

Lance.

Ok, so a wideband without the controller is unusable, I'm going to study the working of this type of EGO sensor before asking another stupid question!

Thank you Lance.

Ludovic

Ludovic,

No problem, if you are interested, there's some background here: http://www.megasquirt.info/PWC/

Lance.