[infinityedge]

http://www.atmel.com/devices/AT90CAN128-Automotive.aspx

It has similar specs to the 2561 but only 128k of memory.

I'm looking at it partially for the integrated CAN bus but mainly for the high temp aspect (up to 125C) as I would like to do an application in the engine compartment.

[androidcho]

2 things you're missing:
1 - Speeduino's code is written in the Arduino IDE, and so the processor must be Arduino IDE supported
2 - 128k is not enough for the configs to go in


Also, you can check for 2560 with industrial grade specs, but I'm not sure if it exists at all..

[infinityedge]

2 things you're missing:
1 - Speeduino's code is written in the Arduino IDE, and so the processor must be Arduino IDE supported

Already looked into that. Most if not all the hard work has been done on that front.

https://github.com/lincomatic/AT90CAN

2 - 128k is not enough for the configs to go in

That was my main concern. But the readme says it will run on a Mega1280 which only has 128k so ithough I'd ask if that still holds.

Also, you can check for 2560 with industrial grade specs, but I'm not sure if it exists at all..

Nope. If you want high temp, 128k is as high as it goes unless you go the 32bit, 3.3v route.

[NickZ]

the only reason it works on the 2561 is we are burning it as a 2560.

[noisymime]

Reading through the datasheet I think if you can get the arduino bootloader on it then it stands a pretty good chance of working, but it maybe limited in cylinders.

There are only 2 16-bit timers on it, which (with the current code) would limit you to 3 inj and 3 ign channels. Enough to run up to 6 cylinder in wasted spark/semi-seq modes.

There's a few areas in the code that may need updating to identify the new MCU, but that's fairly simple.

[PSIG]

... I'm looking at it partially for the integrated CAN bus but mainly for the high temp aspect (up to 125C) as I would like to do an application in the engine compartment.

My first thought - and not that it's a big problem - but all of the components would have to be re-spec'd for not only temperature, but reduced performance. The heat of an engine compartment makes electronic thingies far less capable, and new spec's for capability at the new temperature will likely drive the size and costs up substantially. Just sayin' in-case it hasn't been figured-in yet.

David

[androidcho]

Well, I've seen ECUs of the same engine, but mounted in a different models of a car - on one of them the ECU sits in the glovebox, on the other - it sits in the engine compartment. And that's without any changes to the circutry or the cooling.
But 125*C is way too much..

[infinityedge]

125c is the chip's rating (opposed to 85c for the 2560) not the temp of the application spot. So called "automotive grade" ICs all seem to be rated at this level.

[infinityedge]

Reading through the datasheet I think if you can get the arduino bootloader on it then it stands a pretty good chance of working, but it maybe limited in cylinders.

There are only 2 16-bit timers on it, which (with the current code) would limit you to 3 inj and 3 ign channels. Enough to run up to 6 cylinder in wasted spark/semi-seq modes.

There's a few areas in the code that may need updating to identify the new MCU, but that's fairly simple.

Goodie! Target engine is a two cylinder, wasted spark engine with a modest redline, so that limitation should be fine. Memory isn't an issue?

[PSIG]

125c is the chip's rating (opposed to 85c for the 2560) not the temp of the application spot. So called "automotive grade" ICs all seem to be rated at this level.

Exactly. The chip's thermal junction temperature. Whether it is temperature due to operation, or location, the Tj spec is still limiting performance. The output of a MOSFET or LM or other stuff is lower at higher temperature, whether from general ambient heat-soak, or operating load, or reduced cooling capability. A device in a 100°C engine compartment is at diminished capacity before it's even turned on for restart.

Example - the LM2940-T on the Speeduino boards is good for 1 amp? No, it depends on ambient temperature, load, and cooling capability. So, the LM2940 can supply only 0.2 amps at 5V (spec 23.3°C/W), with an 8V power supply, with a heat sink, in a 100°C engine compartment. That puppy is toast with actual 12 to 15+ volts, and it is rated 125°C. A new part with greater capability is needed, and all the parts must be examined for their performances at the higher temperatures. If an ECM can be used in either the engine compartment or cab, then it was designed to handle the hotter environment, and is loafing in the cooler location. Speeduino was designed for cooler environments to keep size and costs much lower.

David