Which uC for automotive aplication

[gregtherider]

Hi!

Im a student and im working in a company that makes electromotors for electric scooters and small electric automobiles.
Im working on a project for scooter which will be later on used in automobile. I have to make a control board with tft display(displaying speed, batery charge, etc.), monitor a bunch of control buttons and drive a bunch of mosfets for lights so I need a lot of I/O.
The whole thing will be connected on CAN bus and must have USB and bluetooth communication.

Now the easiest way to realize this would be using an Arduino I guess, but it is not an option because all components should be automotive grade.
So Im asking you guys for opinion on what uC should I use, what to look for. I have experience with AVR micros and a little with PIC. Im not afraid to learn something new but I would like to have at least some support like code examples and librarys. I will be using a 3.5" TFT display with ILI9481 IC.
I already found some candidates:
- PIC24HJ128GP510A
-dsPIC33EP512MU810
or should I look for Cortex devices like STM32F103?

Any opinion or suggestion will be appreciated!

-Greg

[Psi]

MSP430 maybe

[nctnico]

I'd go for an ARM device if you want to use graphics. Least chance of running out of CPU power.

[gregtherider]

Yeah, already checked msp430 but none of them seem to have CAN interface. I could use a SPI to CAN chip like MCP2551 but I would like to keep number of chips to min because of limited space.
uC should have:
- CAN interface
- at least 50 GPIO
- optional USB interface or 2 UARTs(one for bluetooth module and one for FT232 for USB connection)
- automotive grade
- good support (code examples and librarys)

[Psi]

yeah, sounds like you want an ARM chip then

[Dago]

I'd use some ARM. Tons of em available, just pick one that suits you. I've heard ST has good datasheets (and heard bad things about NXP) but this is just hearsay...

[dannyf]

Any opinion or suggestion will be appreciated!

If you open up a car, you will likely find Renesas, Infineon and Freescale in there - I think you will eventually find that that's the way it is for good reasons. So that's where I would start.

On the screen side, you will find Fuji / more advanced multi-core ARM chips.

[TheDirty]

I've done a similar project for a replacement gauge cluster for my motorcycle.  I used an NXP LPC1759 for the project.  Unlike most motorcycles, mine has some of the data that the gauge cluster uses going only to the ECU and sends that data to the gauge cluster over CAN.

I would also say any of the more popular ARM Cortex-M3 chips would work.  LPC, ST, Renesas, or Tiva.  If you want something on it that specifically says 'automotive grade' then the Hercules TMS470 maybe.

Pics of my project here:
http://markrules.ca/temp/gauges/
Video:

[tszaboo]

Probably it is obvious if someone points at it, but you have to use Automotive catalog parts for the automotive market. That means you cannot use every part you stumble upon. Freescale, Infineon and Renesas is indeed a good starting point, at infineon I would look for their new Cortex M4, maybe that is not completly F.ked up like their previous ones, with the others I dont have experience.
Also, Ti has the Hercules series, I would guess that it is easier to get support for that. But if you dont have experience with the automotives, get a consultant from the company ASAP. Even your code cannot be any way you want it, and there are way too many standards to now all of them.

mod: And I see, only like 4 times did they say that already.

[nctnico]

Yeah, already checked msp430 but none of them seem to have CAN interface. I could use a SPI to CAN chip like MCP2551 but I would like to keep number of chips to min because of limited space.
uC should have:
- CAN interface
- at least 50 GPIO
- optional USB interface or 2 UARTs(one for bluetooth module and one for FT232 for USB connection)
- automotive grade
- good support (code examples and librarys)

Many bigger ARM chips from NXP have one or two CAN interfaces and 3 UARTS.

[gregtherider]

Well looks like Cortex it is then. But if Im honest Im a little bit affraid to use them because Im not experienced programer and everytime I see some 32bit code it seems so complicated to me. Im used of 8bit mcus and coding there is really straightforward... What is a good starting point for learning Cortex mcu-s?

... But if you dont have experience with the automotives, get a consultant from the company ASAP. Even your code cannot be any way you want it, and there are way too many standards to now all of them.

I guess my boss didnt think that through also, because all he is demanding is using chips with extended temp. range like 105 degrees and above. But as I searched into that subject a bit more I see that its not just temp. range but is also reliability etc.

[jancumps]

TI Hercules range has safety features specifically targeted to automotive, airomotive, trainomotive and medical.
Includes redundant ARM cortex in lockstep mode and focus on error detection and handling.
I am currently investigating the features of the TMS570LS0432 (with their launchpad).

They are designed for applications that need to meet IEC61508 and ISO26262 safety standards.

I am biased but no afiliation with TI

[tszaboo]

I guess my boss didnt think that through also, because all he is demanding is using chips with extended temp. range like 105 degrees and above. But as I searched into that subject a bit more I see that its not just temp. range but is also reliability etc.

That is just verifies my idea, that people in the industry generally have no idea what they exactly doing, or which standards their product have to comply. I'm not excluded.

[zapta]

... Even your code cannot be any way you want it, and there are way too many standards to now all of them.

Can you explain?

[jancumps]

It depends if your device is in scope for such criteria.

Check the two standards I mentioned above for more info.

[gregtherider]

... Even your code cannot be any way you want it, and there are way too many standards to now all of them.

Can you explain?

I read somewhere about that, that some compilers dont allow you to use certain functions or operations that are not compatible with the standard.
Edit: " MISRA : Motor Industry Software Reliability Association. It is a set of unbreakable rules ( and some guidelines ) to be followed when developing code for automitve and mission critical systems using the C language."
Similar thread here:
https://www.eevblog.com/forum/microcontrollers/what-uc-to-use-in-automotive-application/msg120044/#msg120044

[tszaboo]

I read somewhere about that, that some compilers dont allow you to use certain functions or operations that are not compatible with the standard.

Exactly. And for safety applications sometimes they calculate everything using to different method (floating and integer) to avoid silicon errors. Or your RTOS cannot use all the features built in. Or you have to make sure that it is real time. Or you generally cannot malloc/free.
And standards are not free. You have to invest hundreds of dollars just to know, what you have to comply with.
Or your supply chain has to be totally traceable.
Or you have to comply with ISO16001 or any other documentation standards.
And the list just goes on.

[nctnico]

It also depends on the purpose of the circuit. The programming of a radio doesn't need to adhere to the MISRA rules.

[dannyf]

It is a set of unbreakable rules

It is a set of suggestions / guidance that is broken on daily basis, even for automotive applications.

It is good to adhere to MISRA, don't get me wrong. But that doesn't mean it is unbreakable.

[Scrts]

We use Microchip PIC for small applications and Freescale for bigger ones. If DSP is needed, then TI.

[Psi]

As far as i know all the standards for automotive electronics are just so you can say
"Our product complies with standard X"
ie, standards rather than laws ?

I'm not aware of any rules that prohibit selling aftermarket automotive electronic products that dont comply with standard X. Unlike selling tyres for example which require a specific amount of tread to be legal, or children's car seats which have lots of laws around complying with standards.

And even if their are such rules in some countries, if you sell your product internationally then it's really up to the overseas buyer to know the rules in their country before buying your product.

I think having your product comply to automotive standards maybe more about a legal responsibility issue than anything else.
A retail store may refuse to sell your product unless it complies etc..  because they don't want to take on the legal risk if a customer buys the product and is injured due to a design fault then decides to sue.

Correct me if i'm wrong?

[dannyf]

I'm not aware of any rules that prohibit selling aftermarket automotive electronic products that dont comply with standard X.

Or prohibiting selling OEM products for that matter - just take a look at the recent disclosure with regards to Toyota's ecu code. Tons of MISRA non-compliance.

Don't get me wrong: I am a big fan of MISRA and think it makes tons of sense to code to it. But that doesn't mean that you cannot "violate" it.