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#9146 - 07/06/2000 23:28 More tricks with wireless ethernet
steveb
journeyman

Registered: 07/06/2000
Posts: 55
Loc: Sugar Land, Texas, USA
I want to have my car dump all sorts of cool information to my PC over the wireless ehternet when I come home and park it in the driveway. "What kind of cool information" you say? I mean stuff like miles driven, average fuel mileage, average power delivered to each spark plug . . . You know, any information that I could collect with a PIC. I have a new 2000 model truck (I'm from Texas. What do you expect, a honda?) and it has a really intriguing "diagnostic computer" connector. I wonder what fun information could be obtained from it?

Later,

Steve


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#9147 - 08/06/2000 08:09 Re: More tricks with wireless ethernet [Re: steveb]
Tim
veteran

Registered: 25/04/2000
Posts: 1525
Loc: Arizona
When I first ran across the mp3mobile, I had visions of building that thing, sticking in a Data Acquisition card, and running probes all over the car. Calculate the speed needed between lights to make all green lights, the fuel flow... etc. That would rock.


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#9148 - 08/06/2000 14:44 Re: More tricks with wireless ethernet [Re: Tim]
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
If you look at Patrick's thread (Patrick designed the empeg) you will see his stated intent to produce a matching add on for the player sometime in the near future.

I have already started with cabling my motor - three AMD accelerometers are in place, and I am working on building ruggedised linear potentiometers for suspension travel management based on dead gas struts from Ford Fiestas. Cheap! Just add your own CAN bus adapter, and you can get at the lot...

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One of the few remaining Mk1 owners... #00015

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#9149 - 09/06/2000 12:38 Re: More tricks with wireless ethernet [Re: schofiel]
TommyE
enthusiast

Registered: 08/06/1999
Posts: 356
Loc: NORWAY
What is 'AMD accelerometers' ???


TommyE


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#9150 - 09/06/2000 22:32 Re: More tricks with wireless ethernet [Re: schofiel]
steveb
journeyman

Registered: 07/06/2000
Posts: 55
Loc: Sugar Land, Texas, USA
Accelerometers (+-5G I assume?) and dead gas struts for suspension travel management . . . You've got my attention. Tell me more.

Steve


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#9151 - 09/06/2000 22:36 Re: More tricks with wireless ethernet [Re: schofiel]
steveb
journeyman

Registered: 07/06/2000
Posts: 55
Loc: Sugar Land, Texas, USA
I wonder if my 2000 Ford 150 has a CAN bus. If so I wnoder if any of those new PICs have a CAN bus mode for their serial ports. I haven't done a PIC project in about a year and a half so I have not kept up with them. I also have an 8051 development kit, and I'm sure I saw one of those boasting a CAN interface.

Steve


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#9152 - 10/06/2000 12:14 Re: More tricks with wireless ethernet [Re: steveb]
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
Well, I have three AMD 1561 accelerometers (can't remember the full spec - you can go to the AMD website and trawl through their stuff till you hit them) - there are about three different types, and I chose the ones with on-board output amplification, going +/- 3g (I think) which is more than sufficient for a Mini. They are mounted in the three axes and have a multiplexor for axis selection.

The gas struts - well, I just picked up a dead Ford Fiesta gas strut, which had about 9 inches of extension travel. That corresponded roughly to what the Spax shocks on my TR 6 can do (but they don't, of course ) and more than double the expected suspension travel of the Mini. I carefully drilled one end of the casing to release the remaining gas pressure in the struct, and then pumped out the oil (messy). I then carefully cut around the welded seal at the top of the strut casing with a diamond disc on a Dremel, and the thing came apart quite nicely. Although it's difficult to describe the guts of the thing, it is basically a rod with a one-way plunger valve on the end inside a tube casing. The weld seal was necessary for the oleo-pneumatic pressure. I washed and degreased the bits, and then fitted a plastic insulator pipe over the inner rod after removing the valve, but not the end stop. This meant I now had a free-moving linear rod-in-a-pipe setup with an insulated core.

I now hand-wound the insulator pipe with naked 4 thou copper wire (did this with the rod clamped in the drill bit of an electric screwdriver and with the screwdriver turning, gradually wound the entire length of the pipe. LOOOOONG time). Another drill-hole half way up the outer sleeve, insulated spring-loaded carbon brush from a vacuum cleaner goes through the hole to come in contact with the wound inner sleeve on the inner rod, and then tack-welded the cap back onto the sleeve. Bingo! Instant, linear 5k pot, with weather proofing. Cost - about a quid for the strut, 20p for the insulator pipe, a fiver for the copper wire (but enough for about 20 pots), and I raided the parts box for the spring-loaded motor brush. Linearity is not superb, and I had to play about a bit with the wound length to make sure the end stops corresponded to wound parts of the sleeve, but it is *much* cheaper than the real thing (around 220 quid a shot). The difficult bit has been working out how to safely (and rigidly) attach then to the shocks of the car. I have ended up using jubilee clips until I can think of something better (whadda bodge).

I should be able to use Patrick's board with the empeg (given a reasonably stable reference voltage source) to measure the suspension travel and accelerative forces applied to the car (vertical, longditudinal and centripetal). If I have the same setup in each car I have an empeg sled installed in (TR 6 and the Mini at the moment) then I should be able to write an acquisition program for data logging whilst the cars are on the road, and then dump the the data for analysis when I get home. It should then be possible to tweak the gas shocks on the cars to get the best setup for the road conditions I encounter.

Although neither car has a CAN bus (too old), I will be trying to use the Motorola CANbus chipset (can't remember the numbers, so don't ask) to interface via one of the serial ports so that I can pick off CANbus traffic in the future. That's the intent - I wonder if I will manage to get that far? I also plan to look at manifold vacuum and fuel metering unit behaviour on my TR 6 to look and see if the fuelling behaviour of the system is optimum, but that really is a long way off....

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One of the few remaining Mk1 owners... #00015

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#9153 - 10/06/2000 12:17 Re: More tricks with wireless ethernet [Re: TommyE]
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
Solid state directional accelerometers made by Advanced Micro Devices

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One of the few remaining Mk1 owners... #00015

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#9154 - 10/06/2000 14:58 Re: More tricks with wireless ethernet [Re: schofiel]
steveb
journeyman

Registered: 07/06/2000
Posts: 55
Loc: Sugar Land, Texas, USA
With a setup like that you could write a program to do calculations on the fly and adjust the gas struts on the fly giving you an active suspension! It would take a compressor and some controllable valves, but you could control them from Patrick's board.

I'm hopeing my car is CAN equipped so I can get all of that engine info without any real work. It would be cool to show some graphs and displays on the empeg about your current engine efficiency. It could even keep a history and sort of learn the "feel" of your car so that it could alert you if anything looks out of the ordinary, way before anything gets critical.

Steve




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#9155 - 10/06/2000 16:29 Re: More tricks with wireless ethernet [Re: steveb]
Tim
veteran

Registered: 25/04/2000
Posts: 1525
Loc: Arizona
You guys aren't making this wait for the MK2 any easier...


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#9156 - 11/06/2000 01:32 Re: More tricks with wireless ethernet [Re: Tim]
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
Well, it's all available now (apart from Patrick's board).

Even if your car is non-CAN (I doubt it will be yet, as the adoption rate is low and primarily on major German manufacturer's top end models), you should still be abe to jack into the ECU one way or another. There are various ways to get into Ford EEC-IV's for example, and I have managed to read data out of a Peugeot EFI computer while it was running.

As for adjusting the shocks dynamically - can't do it, I'm afraid! The shocks are adjustable, but with a screwdriver to adjust the damping. This is the reason I want to do the measurement work, so I can look for an overdamped response to a suspension impulse and reduce the damping myself, or vice versa. I am a long way off from reliable dynamic suspension!

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One of the few remaining Mk1 owners... #00015

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#9157 - 11/06/2000 14:51 Re: More tricks with wireless ethernet [Re: schofiel]
steveb
journeyman

Registered: 07/06/2000
Posts: 55
Loc: Sugar Land, Texas, USA
The diagnostic connector under my dash is just staring at me. As if challenging me to try and figure it out. Little does it know that I have friends in high places at ford. I think I can probably get all of the information I need.

Could you hook up some king of stepper to that dampening screw? Just an idea. I drive like an old grandma (in fact it was my grandmother who first let me drive, no tha I think of it) so while active suspension SOUNDS cool, I would not even know what to do with it anyway. Besides I drive a Truck, and the suspension is tuned to drive nicely when it is carrying a load in the bed. With no load the back end is STIFF and I can feel every bump.

Steve




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#9158 - 11/06/2000 16:37 Re: More tricks with wireless ethernet [Re: schofiel]
TommyE
enthusiast

Registered: 08/06/1999
Posts: 356
Loc: NORWAY
You've got a link???

TommyE


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#9159 - 12/06/2000 12:59 Re: More tricks with wireless ethernet [Re: TommyE]
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
Errr... you mean a URL to the AMD page?

_________________________
One of the few remaining Mk1 owners... #00015

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#9160 - 12/06/2000 13:21 Re: More tricks with wireless ethernet [Re: schofiel]
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
Actually, I have just realised I have been consistently saying AMD (Advanced Micro) when I meant Analog Devices . Worra plonker.

If you are interested in Accelerometers, they have a good article here, and the data sheet for the devices I am using is here.

Be warned - you need a very stable supply and a low noise environment for your measurements as FSD for this device is quite low. You need to carry out averaging and filtering, but I suggest you read the first article for that.

_________________________
One of the few remaining Mk1 owners... #00015

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#9161 - 13/06/2000 07:53 Re: More tricks with wireless ethernet [Re: schofiel]
TommyE
enthusiast

Registered: 08/06/1999
Posts: 356
Loc: NORWAY
Hehehe, that explains it. I surfed arounf AMD's site for awhile seeking....

TommyE



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