I now have a Bosch wideband sensor winging its way to me (hopefully), and I was wondering what I need to do to make it work.

I could buy a control unit, either one of the horribly expensive ones or something cheaper like the JAW, or I could have a go at building one.

So far I've found out that the heater requires a 9v current-controlled supply. It's a start, but there's obviously a lot more to it!

Are there any DIY designs around? Or links to data about building a controller?

cheers,
David

P.S. I should add that this won't be for use with a fuel-injection system - only for monitoring carbs - so it isn't a critical component.


[Edited on 15/4/08 by David Jenkins]

I ordered my JAW on 30th March, being LOCOST it was the bag of bits and they arrived today.

Just a board componants and digital display, no case or wires but at $46 + $10 shipping who cares, thats only £28 all in.

The board looks well made so will start soldering up at the weekend.

There isnt much info on building a controller about and i think it is a lot more involved than a narrowband as the heater and charge pump must be controlled all the time.
There was a diy wideband project , theres some info on the megasquirt site if you do some searching on there but it needed calibrating with sample gases so not really very diy friendly.
The JAW is the simplest ive seen only problem is the slow deliverys and the web site is taken over by spam so little back up available.There is no circuit diagrams on there either and it uses an Atmel processor that is flash updateable with the firmware.
I think I have sourced one in the uk , will let you know how it works if i get it set up.
Paul

That sounds good hopefully the delivery probs have been sorted out, i emailed a few days back and have had no reply though.
Paul

quote:

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Originally posted by mark chandler
I ordered my JAW on 30th March, being LOCOST it was the bag of bits and they arrived today.

Just a board componants and digital display, no case or wires but at $46 + $10 shipping who cares, thats only £28 all in.

The board looks well made so will start soldering up at the weekend.

---

I am very tempted by the JAW, and the circuit board and components look good, but wasn't impressed by the user instructions - basically, they're almost non-existant!

Also, I put the controller software on my laptop and it's so tall I couldn't get the top and bottom on the screen.

It doesn't give me the warm rosy feeling that it's a finished product (but that's probably just my view as a professional software tester coming out!).

I'd be very interested to see how your system turns out though - maybe my expectations are too high.

One general question though, about when the sensor should be turned on - I keep finding contradictary information when googling. Should the sensor heater be on

a) when the ignition is on, and it doesn't matter whether the engine is running or not;

b) when the engine is started, and not before;

c) after the engine has started.

I've seen each option spouted as 'the only way'!

cheers,
David

quote:

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Originally posted by mark chandler
Just a board componants and digital display, no case or wires but at $46 + $10 shipping who cares, thats only £28 all in.

---

I also found the tuning screen would not fit fully on my monitor and thought it was the monitor resolution but maybe its not.
The sensor should be powered up with the ignition, running the engine with it cold will damage it.
Paul.

quote:

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Originally posted by David Jenkins
I am very tempted by the JAW, and the circuit board and components look good, but wasn't impressed by the user instructions - basically, they're almost non-existant!

Also, I put the controller software on my laptop and it's so tall I couldn't get the top and bottom on the screen.

It doesn't give me the warm rosy feeling that it's a finished product (but that's probably just my view as a professional software tester coming out!).

I'd be very interested to see how your system turns out though - maybe my expectations are too high.

One general question though, about when the sensor should be turned on - I keep finding contradictary information when googling. Should the sensor heater be on

a) when the ignition is on, and it doesn't matter whether the engine is running or not;

b) when the engine is started, and not before;

c) after the engine has started.

I've seen each option spouted as 'the only way'!

cheers,
David

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