Accurate instrumentation possible on a diesel?

[oldbeaver]

Dear Andrzej,

Ok to all. I realized that it is just a constant to be changed, so no need to modify code. Of course!

Clear.

I sent images of the MPguino I have, and of a kind of a TinyGuino I already have. Did you see them?

I need to remember from where in the US I got it to get the parts. It came with some parts included, maybe it use only these.

Do you refer to this Arduido specimen or to another one?

My car is at the garage by now, for a Little stretching of chassis.

Best,

Oldbeaver

[AndrzejM]

Yes I saw those pics. You can use that TinyGuino for a conversion unit, of course. But ATTiny is a single chip that can do the same.

[oldbeaver]

Originally Posted by AndrzejM

Yes I saw those pics. You can use that TinyGuino for a conversion unit, of course. But ATTiny is a single chip that can do the same.

Do you mean something like this?:



When I searched for ATtiny microchip, there showed several versions, small and bigger. For what I can see, you can solder it in any exp board and, yes, put it everywhere.

Two questions:

First: normally Arduino boards and these small chips use 5VDC or even less. How do we get that voltage from the 12 to 14 VDC of the car? I used a voltage divisor or such, with two resistors.

Second: how do we take the analog signals of the car (normally 0-12V) to input them in MPguino and ATmini without a) burn the microprocessor, b) alter the car parameters?

I am weak in electronic knowledge, just able to solder kits and circuits made by others and that is it.

Oldbeaver

[AndrzejM]

Jose,
Take a look here: MPGuino - EcoModder

You'll find answer to both of your questions. First answer is 7805 voltage stabilizer, second answer is 50k resistor and 5,1V Zener diode. But that's for measuring pulses. For analog signals you need a voltage divider made of two resistors.

And regarding ATTiny there are many versions of the chip and we'll find the right one for the task.

[oldbeaver]

Originally Posted by AndrzejM

Jose,
Take a look here: MPGuino - EcoModder

You'll find answer to both of your questions. First answer is 7805 voltage stabilizer, second answer is 50k resistor and 5,1V Zener diode. But that's for measuring pulses. For analog signals you need a voltage divider made of two resistors.

And regarding ATTiny there are many versions of the chip and we'll find the right one for the task.

Ok, so we will customize an instrumentation solution for a 1993 Mercedes Diesel, with the help of MPGuino and some versión of ATTiny. If we succeed, at least many Mercedes diesel cars may benefit of it, starting with mine. Excellent! Thank you for sharing yr knowledge.

OldBeaver

[oldbeaver]

Dear AndrzejM and all Forum guys,

At last, I have my car back home from the garaje, after some painting, radiator repair, change of cooling fan, some body work, passenger seat command repair and several other parts replacements, such as thermostat, wáter pump, and many others.

Step forward:

First, I think the first to do is to identifiy the necessary signals spots to get them, and have them available for use in the Project. Any ideas on a good place and holder of the signal wires ends, hardware to use, and such? I can deliver the signals to inside the cabin or leave them under the Bonnet.

Second, construct a small board where I can solder the zener, the voltaje regulator, the voltaje dividers, and so on. Maybe some led maybe useful to see if there are signals coming. Leave space for the ATtiny. I think it may be soldered here.

Third, have some kind of signal sensor to check before input signals to MPGuino.

Fourth: Install MPGuino, power it and get signals to input it. Callibrate in the car.

I am almost sure I saw some small circuits as to test signals. Not necessary an Oscilloscope.

Andrzej: please give some advice about the hardware to buy, and the circuit scheme, to start building.

Attached are some pictures of the sensors where I plan to get the signals for the Project. There is a picture of the car also.

Looking forward to yr comments and advice,

OldBeaver

[AndrzejM]

Jose,

I think that the best way is to get all signals from ECU harness.
Regarding hardware that you need to buy, first of all you need zener diodes, resistors and working MPGuino. And it doesn't matter which version of the code you have.

Definitely scope would be handy to see what's going on between ECU and injection pump.

[oldbeaver]

Originally Posted by AndrzejM

Jose,

I think that the best way is to get all signals from ECU harness.
Regarding hardware that you need to buy, first of all you need zener diodes, resistors and working MPGuino. And it doesn't matter which version of the code you have.

Definitely scope would be handy to see what's going on between ECU and injection pump.

Ok, I will locate the ECU, make the connections and borrow a scope from someone to start testing.

First, I need to locate diesel ECU,

I think I have a working MPGuino which I may test connecting VSS signal and rpm signal, besides the power and zener diodes. Anyway, the MPGuino I have has its own zeners, and wants 12V input, from what I recall. This will be ok for testing.

I need to prepare a cable and plug to bring signals to MPGuino.

Will take pictures to share with the Forum.

OldBeaver

[AndrzejM]

You're right... You don't need zeners and resistors for MPGuino... I forgot, because I have it build on my own from Arduino Uno. As soon as you locate all signals we need we'll think of converting signals to pulses compatible with MPGuino.

[oldbeaver]

Originally Posted by AndrzejM

You're right... You don't need zeners and resistors for MPGuino... I forgot, because I have it build on my own from Arduino Uno. As soon as you locate all signals we need we'll think of converting signals to pulses compatible with MPGuino.

I think I will not touch the ECU harness at all. Instead, I will get the signals from several harnesses that are almost all identified.

Now I am trying to identify the precise wire based on the color. However, the color code abbreviations I have do not match the ones in the circuits. The ones I have are:

BK black

BR Brown

BU Blue

IV Ivory

GN Green

GY Gray

TR Neutral transparent

OR Orange

PK Pink

RD Red

VI Violet

WT White

YL Yellow

Please see the circuit of the Mercedes diesel injection systems I am sending by email due to its size, and you will realize they are using different color abbreviations.

If you can help me with that it will be nice.

Last minute: these are the German abbreviations for collors, as was pointed to me by AndrzejM. American Mercedes Manuals use a three letter abbreviations, well known for anyone.

Oldbeaver