261 M-Tronic - What makes it tick.....

[breese]

I know on a TS 500i they have a pressure sensor in the case

Interesting.....

 

[Cobby08]

 

[breese]

What saw is that from?

 

[Cobby08]

The TS 500i

 

[blsnelling]

What is interesting is there is a lot of talk about these (or some models) have a type of altimeter.
So far I have not located such a device and I cannot believe (but could be wrong) that it would be within the coil pack.... hmmmm

I have not seen any proof of this either so my assumption is that when they are claiming 'm-tronic adjusts for dirty filters, altitude, fuel quality, etc' they are just assuring that using the same inputs (rpm, throttle position vs the desired tables in the controller) that it will compensate for all those factors.

I don't know why people continue to insist on making this more complicated than it is.

 

[breese]

I don't know why people continue to insist on making this more complicated than it is.

Actually, internally it is very complicated.
Plus, I am very open to more information on all the M-Tronic's out there. Just because one model might not have a sensor, or device another model has, not knowing about it and the possibility of a different On-board controller (like the TS 500i) could open some new doors for me...

 

[blsnelling]

Actually, internally it is very complicated.

I'm sure of that. I'm referring to those that think these saws require all these outside sensor inputs to do what they do.

 

[breese]

It does help to explain some of the documentation....
While it seems all of reads the same, there is nothing (that I have seen) that indicates "on specific models" and such.
Seems to me that Stihl wants the end user to think that All This is available on all the newer products....

 

[Ozhoo]

Stihl's Bus patent can shed some light on the LIN bus question

 

[breese]

Thank you....
This verifies the use of a LIN type network between the Master (coil pack) and Slaves (other devices).

For those not aware of a Lin bus / network...
This is a standard in the Automotive world. Basically it is the method of how the ECM communicates to devices such as an Oxygen Sensor.... (thru the 1 wire connected to it and ground).

 

[breese]

Update:
Seems Stihl has had all the components in this coil pack either custom made and or built without any markings....
The chip I located has no markings and I cannot locate any information on a 30 pin, dual row, chip.
Looking at the traces from this chip, it does a lot more than communicate to the LIN network.

Until such time that I can get my hands on the mdg1 cable, there is not going to be a lot more I can do with the coil pack except trying to trace out all the traces (lots of time to do that).

Next I am going to open the carb solenoid. All devices in a LIN network have a chip and a dedicated network ID address. Maybe there is a stamp on that chip that will give me an idea of who the manufacturer is and if it is a standard LIN type device.

 

[MustangMike]

Looking at the traces from this chip, it does a lot more than communicate to the LIN network.

Fascinating stuff, I think a lot of people have under estimated the complexity of this system.

 

[Duane(Pa)]

They (Stihl) don't want you know who built it or how it works. Trade secret. I would be shocked, maybe even dismayed, if it wasn't a Bosch system...

 

[breese]

I think a lot of people have under estimated the complexity of this system

I for one.... While I understand a lot of the after market high performance ignition systems (being a old racer myself), I never expected this much to be packed into such a small, high temp space.

They (Stihl) don't want you know who built it or how it works. Trade secret. I would be shocked, maybe even dismayed, if it wasn't a Bosch system...

I understand why they are doing it... I am more amazed that someone (a hacker) has not done this in the past... There is a lot that can be learned from this technology and there are those (out there) that love a good design.
Bosch is a maybe... A lot of the (so called) 1-wire systems are done by a very few companies and I have seen nothing regarding Bosch...
Then again, I cannot even find a reference to a 30 pin, dual row, surface mount chip.... oh well.

 

[nohoff]

Some of the engineering work was done by gigatronik.

http://www.gigatronik.com/en/industries.html

Maybe someone has informations about their car-diagnositic systems, as some companys tent to work only with a few other suppliers.

I saw that delivery to USA is only 16 Euro so i can send you a lot of defective M-Tronic parts (coils,carbs and starter switches)

 

[MustangMike]

I'm from the old amateur racer era that thought replacing points with electronic ignition was high tech!

My brother and I both favored the old Mallory Photo Cell electronic ignition that utilized the OEM distributor.

 

[retro]

Update:
Seems Stihl has had all the components in this coil pack either custom made and or built without any markings....
The chip I located has no markings and I cannot locate any information on a 30 pin, dual row, chip.
Looking at the traces from this chip, it does a lot more than communicate to the LIN network.

The package type is known as TSSOP. Texas Instruments uses the TSSOP package for many of their highend analog & A/D chips such as class D amplifiers, power monitors, converter/chargers etc. TSSOP pin configurations commonly vary from 16 to 44 pins and have been in use for a long time. My first homebuilt class D amp was based on a TI TSSOP die many years ago.

I didn't expect there to be any identifying marks on any of the ICs. There never is... not ever.

With the MDG1 and software, hopefully you'll be able to make some headway. Do you have a good (old-school) decompiler? A good debugger/editor? Big shortcuts if you do...

 

[mdavlee]

and why they can keep up with ported saw needs and cover up bad air leaks. they seem to have great capacity to over fuel.

Yes. They can over fuel on methanol. Never tried nitro mixed in.

 

[breese]

The package type is known as TSSOP. Texas Instruments uses the TSSOP package for many of their highend analog & A/D chips such as class D amplifiers, power monitors, converter/chargers etc. TSSOP pin configurations commonly vary from 16 to 44 pins and have been in use for a long time.

I grabbed some of the documentation for this chip set.
While there is a programmer / debugger available and has the ability to communicate thru 4, 5 and even 2 wire communication, there is nothing in the specs indicating the 2 wire connection also passes power across these same lines.
Some of the documentation even shows it requires a 3rd line (voltage) from the programmer to the chip along with the 2 wire. Also, this 2 wire appears to be a real 2 wire and would not work if one was for data and the other for ground such as the case in these M-Tronic saws.

 

[breese]

As I wrap my head around this, I have discovered the current hardware methods being used to Advance timing on any electronic ignition saw will produce the same results as an M-Tronic.

Advancing the timing by means of a modified hardware key (lets say 5 degreese), will in all affect only do just that...
The internal chip / software only has one method of knowing TDC and that's thru the trigger sensor (on the Sparkplug side of the coil) and the flywheel.

As a result, if you take a stock M-Tronic, connect a timing light and take measurements at 1000, 4000, and 6000 RPM's, then do the same for a modified, 5 degree advanced saw, the timing light at those same speeds will be advanced by exactly 5 degrees.

There is no other sensor / method for the saws electronic ignition to know something has changed except for the trigger sensor.

Now if a software change could done to set a 5 degree advance, the saw would need to make 2 maybe 3 revolutions on Startup so as to Power Up the chip, read the trigger sensor, and make the preprogrammed adjustment.

On the other hand, some type of mechanical movement of the coil pack as the throttle is being used, could result in a faster responding acceleration because the coil would be physically advancing and retarding the timing....

Just throwing it out there.... Something that came into my head and needed to verbalize it....
LOL