Wanted 8v speedo for parts

Wait, there's hills?

Stubbie, some small rise called the Great Dividing Range. Great for corners - point and shoot is a good game.

Can you give some detail of what and where the air pressure sensor looks like and is located ?

It looks as if you're half way to duplicating the sensor so detail of what you've installed would really help.

If you've already worked out what the baseline output is for sea level then hopefully it won't be too
difficult to work out a variable output module that mimics the original unit.

If that can be sorted I already have solved the other issues. It should be possible to put together a complete tutorial of how to run without the original speedo and electronics.

It was not I. I read about that fix on a Honda web page. What I posted there was all that was available.

I have looked at what is available and there is a Bosch unit (BMP280) for a few dollars (well perhaps $10 for a pack of 2 from RS).

the output is digital and would require some added electronics to get an analogue signal out. I suspect this is done in the dash, anyway. You would be looking for a device with a hole in it. Here is the data sheet with photos...
BMP280

Maybe, just maybe, this could work natively with a bit of work.

Does anyone know how the dash and ECU really discuss things?

Building something like Stubbie suggested, would really be a no-brainer - even a trimmed up version (adjustable for when you go into those mountains) - not terribly accurate but it could be done, once we know what the ECU requires.

I've seen APS available for EFI systems on vintage cars so it must be able to be done.

Oz1200Guzzi wrote:

Does anyone know how the dash and ECU really discuss things?

CAN bus.

So all digital

Aye.

Hi Beetle
What's your opinion on trying to use the Bosch air pressure gauge referred to by Don ?

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WTF is Don?

It will need an I2C interface to extract the relevant info, then it will need some CAN adjustments. Evans I would say it's altogether too hard for what you want. You could gut the speedo and just use the guts under your seat...

I still reckon if you want to remove the dash, the Arduino is the best option. It can talk OBD over CANbus. Unfortunately, Guzzi doesn't subscribe to the OBD standard 100%, so you will need to sniff and debug the entire serial comms protocol. You only need the handshake and APS data, at a minimum.

Sounds too hard? Yep.

A technical challenge nonetheless - though I am sure the effort will not be worth it in the long run. I did think Arduino in my section above (to convert the I2C to CAN shit) but probably it's all theory anyway.

Ah I thought we were getting somewhere.

Personally my bike is running fantastically with the old speedo connected and hidden in the tail tidy.

Since they've stopped making Grisos and the original speedos are so expensive I was hoping to be able to find a way for those who needed it to do without the original unit without downgrading the tuning or breaking the bank.

Tony I didn't see the signature at the bottom of your posts but saw Don Abbodino under under OZ1200guzzi. I guess I should have written "The Don"

Just having a look at what was on ebay for Grisos
A new speedo at US$1,015
For relatively minor component of the bike as a whole that's a lot

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Yeah, they are pricey. They're pretty reliable on the GRiSO. Easily smashed though in the event of a spill.

Evans, probably your best bet is the old speedo from Mr Bob, take of the plastic shrouds to get the bare minimum and store that in your storage area. Keep the original as a spare.

Thanks, that sounds like a plan.
Although it's not going to be easy I would like to crack the problem.

As you can see from the cost above, replacements are expensive and I suspect will become hard
to find as time goes on.

Finding alternatives could keep Grisos going where otherwise they were stuck due to the cost of repair
or unavailability of the parts.

Evans wrote:

Hi Beetle
What's your opinion on trying to use the Bosch air pressure gauge referred to by Don ?

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This sensor looks to be similar to the one I found on the GRiSO version of the board, as shown in photos 4, 6, and 7 in the first of my series of four long posts on waterproofing, here:

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Photos of the Breva/Norge/Sport 1200 dash show the same module.

At 2.0 x 2.5mm the sensor is about the right size, with the right number of pins ( 8 ). By googling bmp180 or bmp280 you can find plenty of info on two generations of the sensor, and Arduino module(s) containing them.

I expect the Guzzi sensor might be one or the other of the two versions of this Bosch item. This is a nice find by "Don."

Moto

Does this mean that one of these can be used to replicate the one in the original set up ?

If so how would you go about it ?

Previous posts seemed to put it in the too hard basket.

It would be good if there is an alternative to the original speedo / rev counter.
Replacements are really expensive and I suspect will become harder to find.

Unless you want to go into full blown digital electronics design and the iterations that this will take, the diagnostic gear and all the time it takes to do it, probably best to walk away Evans. You've got a solution that works - go ride.

Evans wrote:

Does this mean that one of these can be used to replicate the one in the original set up ?

If so how would you go about it ?

1) don't know. quite possibly.

2) I would Google for information as described earlier, and read up on the interface. I would probably investigate using the Arduino module. But I don't have any intention to do this, since I long ago waterproofed my dash, using the methods described in those posts I referred to!

Good luck.

Moto

P.S. l recall finding a BMW motorcycle that uses the same ECU, but with an external pressure sensor. I forget the model. That might be another way to go about it, but there would be no guarantee that the interface to the BMW is the same as the one to the Guzzi dash.

M.

Millipercento might have something you could use Evans. Just saw something on YouTube where they were running what looked like their own speedo on an 8V engine.

Millipercento