Husqvarna Autotune software

Take 4 left turns, that should straighten you back out.

 

This is so beyond me but very interesting

 

I can start my old school Stihl 026 but it takes a sharp ear to hear that first burp or I flood it. My Husky 555 with the autotune is a breeze. One or 2 pulls and even if I don't hear it I can see the compression release has popped up. Take it off choke and the next pull it is running. I'll take the "modern technology" every time.

 

I never had a problem with the AT on the 576 or 550. Started easy as quick as my regular carb saws.

 

My AT saws start right up also. You just need to set high idle when they are warm but they start right up.

 

When my 362 is warm you just pull the rope once and it starts. Don't even need to set the switch.

 

Really? I don't set the switch to high idle on mine for warm re-start. Do I need to rtfm?

 

It couldn't hurt. If I am restarting within a couple of minutes I just pull the cord but if it has been sitting aside for 5 or 10 minutes the high idle gives a more consistent first pull start.

 

I get what you're saying, but my 3 standard carb saws start predictably and warm start on the first pull too. So I'm not sold on electronic tuning either way.

David

 

This could be awesome for us AT owners. Subscribed.

 

Has anyone make progress on reverse engineering the interface?

I recently heard from a dealer that the autotune software is useless for consumers because Husqvarna now requires the software to log into the Husky dealer website to function.

Being an EE and a Ham Radio operator I am used to reverse engineering software protocols and building hardware interfaces. Just need a place to start.

 

I've run into the same issue. I bought the Diagnostic Tool and I can't find a copy of the CST and even if I had it I don't have a computer that can run it.

I have a Mac and a Linux machine.

I took apart the Diag tool and it's pretty simple inside.

There's a FTDI USB to RS232 chip (at TTL level) connected to an Atmega164P 8-bit microcontroller and some output hardware. Not much else.... all the components are on the top of the board and it appears to be only a 2 layer PCB, but I haven't checked closely.
Datasheets are available on the mfg websites.

I'll pin the thing out and draw up a schematic later. The hard part is the protocol (as someone said). I have some ideas on how to deal with that... but its very labor intensive.

I also haven't figured out what interface the saw per-se uses... with only 3 pins... well, its unclear to me what would make sense there. I have to do some poking around.

It would be really nice if Husqvarna published an ICD for that interface. I don't know why companies consider this proprietary or whatever.

If I have to face this kind of dealer-lock-in-money-suck it is basically a deal killer .... I will never buy another product of theirs.

There's a reason I own a Kubota instead of a Deere and didn't even look at one. Deere is the worst for dealer repair lock-in.

 

Hello
Welcome aboard
I’ll keep that in mind if I find myself tractor shopping
Good to know

 

This thread has convinced me that I won't be getting a computerized Husky. Too complicated and too much trouble just to run a small engine and pull a chain around a grooved bar. I will say though that I am beginning to like my little Stihl 261 CM, and once I learned the right way to start it, I find it to be very user friendly on the starting up, etc. But that is as far I ever want to go on electronics to run small engines.

 

I think you’ve already crossed the line with the Mtronic

And I agree, except for legacy known issue on a vintage of the 550XP, I find them very user friendly

 

I like to cut wood. My chainsaw go BRRRRRRRRRRRRRR.

 

I would guess the 3 wires are Rx , Tx , and ground. Protocol is probably logic level UART.
I would watch the signals with a scope to determine the baud rate. If it logic level signals you need to get it back to RS-232 levels
so you can connect to a PC running something like realterm.

SparkFun RS232 Shifter - SMD - PRT-00449 - SparkFun Electronics
Need this is the signals are logic level.

RealTerm: Serial/TCP Terminal

Realterm can log the entire data exchange if you set it up correctly.

Be prepared for the possibility that there is a basic encryption on the communications. If you find that sending the same request repeatedly causes different data to be exchanged each time then this is likely the reason.

 

What I haven't thought through is how the chip on the saw is powered if there are only three lines: Tx, Rx and Ground. Presumably its powered by the saw when the engine is running, but its unclear to me how long it could run w/o a super cap or battery or external power while you are trying to talk to it.

I also don't know yet if its 1.8v, 3.3v, 5v or RS232 (-12 to -25 swing).

There are ways to power via logic lines, but that's pretty atypical. I'll know more as I dig into the board.

If someone has a spare auto-tune carb that they want to sacrifice to the cause, I'm more than happy to take that apart and see what the electronics on-board look like.