Interfacing Propeller board to Car

[jbalat]

Hoping someone with some electrical knowledge can help me interface my board to the car.. This is my first post here so be easy on me

Ok so I have purchased a Parallax propeller chip which is a really cool device that can run 8 processes simulataneously at 80MHz

Only problem is that it runs on 3.3v.. Hence my problem how to interface this device to my 5V logic on the (Mitsubishi) Air sensor to Read the signal and send a modified 5V signal to the ECU (50% duty pulse 0.8v - 4.8v).

This is what I have come up with so far but I dont get an output signal so I am guessing that it is not reading the input signal properly.. Works fine on the bench simulating the Airflow sensor with a 5V Stamp board but wont work in the car?

**broken link removed**

 

[parts-man73]

It's much simpler than that. Here's a quote right from the Propeller's designer.

To input from a 5V system, a series resistor in the 1k-100k range is probably the best approach. There are parasitic catch diodes on every pin of the device which will clamp incoming out-of-range voltages to within ~0.4V of the VSS and VDD rails. This will force the resistor to drop 1.3V (5.0V-(3.3+0.4)) for an incoming high signal.

To output to a 5V system might be a simple matter if the threshold voltage is TTL (~1.4V) or CMOS (2.5V). You can connect straight in. For bidirectional pins, just use a series resistor.

 

[parts-man73]

....or, a more elegant approach.

SparkFun Electronics - Logic Level Converter

SparkFun makes these level shifters. They also supply a schematic if you want to "roll your own"

 

[DirtyLude]

That's some pretty hefty processing for a piggyback system.

 

[blueroomelectronics]

Hope it's not an IAT mod.
IAT Mod - Fact or Friction?

 

[jbalat]

I will try just a plain 1K on the air meter side and nothing on the ecu side just as a quick check. Thanks

The SparkFun thing also looks great, just need to source one in australia if the above doesnt work

As for whether it will work ???? I am trying to reduce some of the fuel going in to the engine to replace it with HHO which I am generating from my alternator.. I dont want a debate on this, I just want to see if it works by trying it out. Without the MAF mod the ECU sees extra O2 coming in and runs the engine richer therefore using more fuel than without the HHO.. Yes I will disconnect the O2 sensor when I get this MAF board working. Car runs ok without it but uses about 1Ltr/100km more fuel.

 

[DirtyLude]

Hope it's not an IAT mod.
IAT Mod - Fact or Friction?

It actively modifies the mass air flow sensor, so it more directly effects fuel without giving up actual air temp correction. It's usually a more advanced version of the IAT sensor mod. A lot of commercial versions of these exist and they usually allow on/off throttle/rpm mapping entered by the user.

Without getting into an argument about how well this piggybacking works. My comment was simply that a $1 4Mhz 8bit microcontroller would do this.

 

[jbalat]

Mark, thats great if you know how..but being a mere mechanical engineer with only V=IR to my electronics skills I thought the propeller looked like the way to go..

It gets worse. I tried using a BS2 stamp and PWMPal at first but it was too slow and can only do one thing at a time so it didnt work...

So I have spent my fair share of $$ on this project but I think well worth the experience I have gained

P.S. I have already tried the IAT resistor trick with no luck besides retard the timing there is not enough effect to lean the mixture enough.. Just purchase a couple of level shifters, thanks for the link found an aussie ditributor from WA

 

[jbalat]

Just an update to say the simple method using resistors did not work...(Boo hoo)

Now I need to wait for the level shifters and hope that works.

 

[parts-man73]

I don't understand why a simple current limiting resistor would not work. Have you looked at the signal from the sensor with a scope or logic analyzer? Might be a problem with your code? ?

ViewPort software has a free 30 day demo. You can use the Propeller as a scope or analyzer, with that sensor attached with a simple resistor and look at the signal visually on your computer screen. May help with your debugging, both hardware or software as needed.

link to ViewPort ---> **broken link removed**

 

[jbalat]

I have an oscilliscope. I get 0.8 to 4.8v going to earth when I probe the wire connecting the Airflow meter and the ECU (wire 3-10). An amp meter inbetween gives me 4mA

When I measure current from the propeller I get about 0.25mA and pulse of 0-2.96v

There are internal resistors and transistors on the MAF side and ECU side. If the impedance is not right or the ecu does not see a pulse or the pulse doesnt change in relation to the throttle position sensor then the ECU goes to open loop and ignores the signal and appears to cut power somehow ? (I think it may do this through wire 7-57 below)

I need to supply 5v power to the MAF to get it to work this is through a resistor of 1K


Tell me what I need to measure to get the right impedance on both sides ?

This approach below worked with my 5V BS2 stamp setup but signal was not smooth enough because of retriggering issues with the PWMPal and low speed operation of the stamp.
**broken link removed**

 

[Oznog]

Mark, thats great if you know how..but being a mere mechanical engineer with only V=IR to my electronics skills I thought the propeller looked like the way to go..

It gets worse. I tried using a BS2 stamp and PWMPal at first but it was too slow and can only do one thing at a time so it didnt work...

So I have spent my fair share of $$ on this project but I think well worth the experience I have gained

P.S. I have already tried the IAT resistor trick with no luck besides retard the timing there is not enough effect to lean the mixture enough.. Just purchase a couple of level shifters, thanks for the link found an aussie ditributor from WA

Well, the Propeller is a grossly inappropriate solution for the job. In fact I've never quite understood what the point of the Propeller was, and I found it difficult to read their literature when they kept using their "in house" terms for things, in short, it seems like doublespeak.

Likewise, Basic Stamps... well, it's not "as bad", but I've said it before, IMHO Basic Stamps are largely pointless. They're expensive repackaging of a PIC. There's a PIC on them. The PIC is very easy to learn and use, and they're cheap. The Basic interpreter added to it is extremely slow and requires external ROM for the program, which is absurd since there's already tons of program ROM on the PIC itself. They push they as being "easy" for classroom use, but it's not really any easier than learning C, and the experience is largely useless because you're not going to be able to reuse your Stamp Basic code and knowledge when you finally decide to start programming on a PIC itself.

It is not going to be easy to find people who can help you work out issues with Propeller chips. Few people use them. On the electrical side, we're giving general-purpose advice, which will PROBABLY work for this.

And what blueroomelectronics says is sadly true. All cars are run somewhat short of the ideal stochiometric ratio (exactly enough O2 to burn the fuel to H2O and CO2) because that makes the piston temp run far too high and it can damage the piston and produce terrible amounts of NOx. The IAT (or any other sensor) being modified CAN lean out the mixture and yield marginal gains in mpg- about 10%, IIRC- but it will lead to very poor emissions. And it can damage the catalytic converter, burn the valves, even blow a hole in a piston.

It is not likely to be able to justify these measures because, well, if it was justifiable the mfg would have already done it. Govt standards on mpg are tough to meet and anything that allows the car to be slightly bigger and heavier and still meet mpg standards is worth a lot to them! But, having 30% of your engines come back blown within the warranty period is too much.

And the HHO idea is an all-around myth and fraud, unfortunately. There is NO way an HHO generator is going to produce chemically significant amounts of H2 and O2. The basic problem is that the horsepower needed to produce H2 and O2 from water is much more than the additional HP produced from injecting it into the intake. Even if the computer response is ideal. So any plan to scale it up to something larger- a 3L engine at 2000 rpm needs 4800L/min of fuel/air mixture- will always require more additional drag on the engine than it adds in fuel, resulting in more gas consumption.

Some of the confusion over HHO or any of the fuel "hacks" is that they're causing that overly-lean mixture, which has nothing to do with HHO. It still comes with terrible emissions and a very real, constant risk of engine damage.

 

[jbalat]

Im grateful for the help I have received so far. I have tried the propeller forum but thought this is more an electrical/installation issue due to the specific nature of my ECU and sensor... Please keep suggestions coming... Like I said I can get the system working on the bench no problems..

Thanks Oznog.. This is your own opinion. I am not yet convinced about HHO myself that is why I want to give it a fair go before I give up and call it a scam

Here are some opinions from other people that have made gains and others that have not.. **broken link removed**

From what I have understood.. the amount of energy extracted from the hydrogen will be less than the energy from the alternator and therefore drag on the engine than what it took to create it. However it is supposed to create a better and faster burn of the fuel in the cylinder by acting as a catalyst. This uses up more of the unburnt fuel to create power and produce less wasted energy such as heat that dissipates in the engine. If the efficiency of the normal ICE cycle is at best 20% then the hydrogen catalyst only needs to increase that by 2% to get an overall 10% gain in economy..

This is the mainstream brute force method of creating hydrogen..If you want to get into some freaky stuff then you can "supposedly" generate up to 100Ltrs of hho/min using resonance with the hex controller board. This will allow you to run the car without any fuel at all.. Google D9.pdf

 

[Oznog]

Thanks Oznog.. This is your own opinion. I am not yet convinced about HHO myself that is why I want to give it a fair go before I give up and call it a scam

Well, if you mess with the computer, you MAY well see a marginal gain, thus appearing to be evidence HHO "works". But you won't be able to see what it's doing to your engine and emissions. And it has nothing really to do with the introduction of HHO.

From what I have understood.. the amount of energy extracted from the hydrogen will be less than the energy from the alternator and therefore drag on the engine than what it took to create it. However it is supposed to create a better and faster burn of the fuel in the cylinder by acting as a catalyst. This uses up more of the unburnt fuel to create power and produce less wasted energy such as heat that dissipates in the engine. If the efficiency of the normal ICE cycle is at best 20% then the hydrogen catalyst only needs to increase that by 2% to get an overall 10% gain in economy.

Which is unfortunately rubbish. Lemme explain.

Fuel burn does not need to be "faster". In fact, a primary concern of a piston engine is ensuring combustion is SLOW enough. If fuel combusts too quickly, it's explosive and this is called detonation or knocking. It provides little or no additional energy but it's extremely stressful on pistons and valves. The WHOLE reason for octane is to actually ensure a slow, controlled combustion flame front. In higher compression engines, that's a major problem, so they need high octane to slow the burn.

There's not a lot of unburned fuel at the end of the cycle in a properly working engine. AFAIK this is not a major loss to begin with. The figure of an ICE being only 20% efficient is irrelevant because the hypothesis is only about improving on unburned fuel, and unburned fuel should not be such a huge part of the loss.

This is the mainstream brute force method of creating hydrogen..If you want to get into some freaky stuff then you can "supposedly" generate up to 100Ltrs of hho/min using resonance with the hex controller board. This will allow you to run the car without any fuel at all.. Google D9.pdf

Impossible. There is plenty of industrial work on creating hydrogen. There is no "resonance" to the process and "pulsing" does nothing but generally reduce the efficiency. They're total fiction. It's impossible to make more H2 and O2 than the energy you put into it! Nor is there any magic catalyst which can make energy out>energy in.

Production of H2 and O2 can be massively effective when using platinum electrodes and very strong potassium hydroxide electrolyte (this will eat your skin off, and unfortunately amateurs have appalling poor safety practices)- and adding distilled H2O, because minerals in tap water (even "filtered") will build up and quickly poison it. However, won't change the energy out<energy in rule.

There IS actually one exception, and that's that electrolyzing water into H2 and O2, as electrolyte temp is increased, will actually use thermal energy- heat- as part of the energy. Thus it IS possible that the potential energy of H2 and O2 can be somewhat greater than the electrical energy put in, if the solution is kept heated by an external source, like the catalytic converter, which is "wasted" anyways! It's free energy! Yes, but don't get too crazy about it. Because the amount of energy recovered from heat this way is not large, the temp must be quite high- so high it requires remarkable materials, the vessel must be highly pressurized so the electrolyte doesn't boil, and there's a technical problem of H2 and O2 spontaneously recombining into H2O in the solution as temps increase. Then the fact remains that burning H2 and O2 in an engine only returns like 20% of the energy put into it anyways. So even if you were to get a 200% electrical efficiency: 1000W of electricity, 1000W of heat to make 2KW of energy stored in H2 and O2 you'd only get 400W of extra shaft HP, for a net loss of 600W.

Unless you're gonna rely on the theory of hydrogen being some sort of aid to improve combustion- which has never been scientifically justified that I've seen. And, since it would be a very scientifically observable effect and the world is full of chemical engineers who deal in combustion, it SHOULD have readily available technical papers on that effect. If it were real.

If a peer-reviewed paper shows up, I'll readily believe it for what it says. If you've got a link to a technical paper, I'd love to read it. But the anecdotal claims (and amateur-made charts) are worthless- people claim their fuel increased to 100mpg by "magnetizing" the fuel, or use a "spinner" on the intake air- few believe that. But claim it increases by 10% or 20% and people WILL believe it. And people will claim they did it.

BTW, I did try adding the prescribed amount of acetone to my fuel once in my '87 van. Didn't improve the mpg that I could see, but it failed emissions. Ran that tank out, did some minor maintenance (air filter, spark plug wires) which probably wouldn't affect the emissions, but anyhow, took it back when the acetone got flushed out it passed just fine!

 

[Oznog]

Actually I should probably restate the problem. I can't entirely say that the theory of adding small amounts of H2 and O2 might be able to improve combustion, increasing energy output greater than what was required to make the H2 and O2. I find it unlikely, but can't rule it out as impossible. The major credibility problem being the absence of any professional study of the claimed effect, esp when there should have been many opportunities to study it.

What I can say is that no amount of amateur experimentation will be of any use. Driving slightly differently can get you 10% better mpg. Air temp and pressure can change the mpg. Tire temp can change it. People in your car and junk in the trunk will reduce it by 10%. Getting gasoline with less ethanol in it may get 10% better mpg. Measurement errors can change the mpg by +/-30%. And of course people who are crazy- or scamming- can change the results by any % they want. More to the point, you won't understand if you've created a dangerously lean condition or produced irresponsible amounts of emissions. This unfortunately makes the "testing" pretty much worthless. You can fool yourself into thinking you have observed something, but whether you improved or not is not even really possible to observe this way.

Mythbusters did try the HHO generator off the internet, BTW. Didn't help. I don't think they tried to tamper with the computer.

 

[jbalat]

Sorry I dont want to argue this stuff.. If you are interested you can look up the SMACK SUPREMACY videos on youtube
YouTube - The Smack Supremacy 1

Can anyone help interfacing my board with the ECU. This is my primary concern at the moment

 

[Oznog]

Well, the zener and 5v is actually not appropriate for you, although it should work.

Since the MAF is just an open-drain pulldown in your pic (assuming this is correct- and it's not improbable), just put a 1k resistor between the 3.3v Vdd used on the Propeller and the MAF output. It'll be 3.3v when not pulled down and ~0.3v when pulled down.

The 3.3v zener is not going to be really accurate, which is why you got 2.96v on it. But that should be enough to qualify as "High" on the Prop. When you say "not working", what do you mean? No output? Do you even know if your code works?

How is the Propeller being powered? You didn't describe a 3.3v reg anywhere. Was the zener supposed to be a shunt reg? That's not readily going to work well on a 3.3v system because low voltage zeners have a VERY poorly shaped "knee" on the IV curve.

I still gotta repeat this point, because it's still important- you're REALLY using the wrong chip for this. I really don't know how else to say it: this chip is a bad choice and creating far more questions and problems than anything it could solve (which is nothing, really). Get a 5v PIC in the 18F series and you can write C for it and run debugging on it as it's running. Or, this job will do just fine with a 12F.

 

[Oznog]

Sorry I dont want to argue this stuff.. If you are interested you can look up the SMACK SUPREMACY videos on youtube
YouTube - The Smack Supremacy 1

Speaking as an engineer who has followed the "fringe science" community for some time, I can just tell you right now- this guy is actually giving every indication of being an unreliable quack. He sounds almost identical to Troy Hurtubise, and a little like the Ghost Hunters guy. The mindset is basically crazy and deluded and covering with it with big words and pretending to be scientific. There's a LOT of problems with what he's actually saying that clearly show he's into pseudoscience, not science.

 

[jbalat]

Yeh I noticed the wave was not exactly square with the zener and there was some noise so I removed it.. now and I am just using the 1K on the line from the propeller input pin to the MAF sensor.

I have already tried using 3.3v to feed the MAF but I could not get a pulse back so I had to go to 5V. I used a pot on from the 5V line to the MAF and worked out that around 3K on that line gave the highest voltage back to the Propeller input pin. Even at best case it was only around 2.7v but as you said it should trigger a hi..

Oh yeh I fitted a simple 9V regulator on the board with a capacitor across the earth and 9V leg so that it is powered from the CAR directly off the HHO cell power. The board itslef has a 5V and 3.3v reg fitted. It is **broken link removed**

As for the Output side it tends to stop pulsing even on the bench so not sure what is going on there.. I will go back to the bench and try to debug. In the meantime let me know if you want me to take any other measurements ?

I would love to try the pic but now that I have the propeller I may as well use it.

On the other topic.. you must admit though that the SMACK is very entertaining..

If you know anything about electronics and winding your own toriods I would love to get you talking to Bob Boyce. He is the designer of the hex board which can generate power from the environment. He has posted a simple challenge for non-believers but I dont have the knowledge to even know what he is talking about...He is a bit of a legend amongst the HHO community so if you are just going to tell him that he is on drugs I'd rather you not get involved. Otherwise head to **broken link removed**

 

[Oznog]

If you know anything about electronics and winding your own toriods I would love to get you talking to Bob Boyce. He is the designer of the hex board which can generate power from the environment. He has posted a simple challenge for non-believers but I dont have the knowledge to even know what he is talking about...He is a bit of a legend amongst the HHO community so if you are just going to tell him that he is on drugs I'd rather you not get involved. Otherwise head to **broken link removed**

Oh we KNOW what he's talking about. We've got years of experience with the guys claiming "free energy from the environment". And they're all frauds. I don't know what you expect a fraudster to look like, but they can come in all forms. It is impossible to generate energy out of nothing, and there is no magical ether-power floating around. The claim is not new. It's very VERY old. They're often claimed exactly like he does, they claim there are "verified test results", they claim other people have verified them, sometimes people show up claiming to have verified it. Some have official, legal "corporations". They're still 100% frauds... all the time.

Toroids have been understood for years. They're just a variation of the iron-core inductor (or transformer) with improved saturation, eddy current, and magnetic leakage properties under some conditions. They follow the rules of physics 100% and there's nothing magic about what they do.

**broken link removed**

LOL he sold this "board" to Watkykjy1 for $1200? I guess you CAN generate something out of nothing. I could pay the electric bill for quite a while with that!

**broken link removed**
Or you can "wind your own" with his $190 toroid kit?? I don't think he needs any help there. Already knows how to turn iron core into gold. You start with an iron core, and find a sucker with some gold...