Which uC for automotive aplication - Page 1
Forum section: electronics / general

author: gregtherider
author_rank: Newbie
timestamp: January 03, 2014, 12:28:15 pm
content: 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-dsPIC33EP512MU810or should I look for Cortex devices like STM32F103?Any opinion or suggestion will be appreciated!-Greg

author: Psi
author_rank: Super Contributor
timestamp: January 03, 2014, 12:30:46 pm
content: MSP430 maybe

author: nctnico
author_rank: Super Contributor
timestamp: January 03, 2014, 12:40:13 pm
content: I'd go for an ARM device if you want to use graphics. Least chance of running out of CPU power.

author: gregtherider
author_rank: Newbie
timestamp: January 03, 2014, 12:48:05 pm
content: 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)

author: Psi
author_rank: Super Contributor
timestamp: January 03, 2014, 12:54:32 pm
content: yeah, sounds like you want an ARM chip then

author: Dago
author_rank: Frequent Contributor
timestamp: January 03, 2014, 12:58:49 pm
content: 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...

author: dannyf
author_rank: Super Contributor
timestamp: January 03, 2014, 01:00:20 pm
content: QuoteIf 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.

author: TheDirty
author_rank: Frequent Contributor
timestamp: January 03, 2014, 02:13:02 pm
content: 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:

author: tszaboo
author_rank: Super Contributor
timestamp: January 03, 2014, 02:38:26 pm
content: 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.

author: nctnico
author_rank: Super Contributor
timestamp: January 03, 2014, 02:52:13 pm
content: Quote from: gregtherider on January 03, 2014, 12:48:05 pmMany bigger ARM chips from NXP have one or two CAN interfaces and 3 UARTS.

author: gregtherider
author_rank: Newbie
timestamp: January 03, 2014, 03:30:44 pm
content: 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?Quote from: NANDBlog on January 03, 2014, 02:38:26 pmI 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.

author: jancumps
author_rank: Unknown
timestamp: January 03, 2014, 03:46:38 pm
content: 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

author: tszaboo
author_rank: Super Contributor
timestamp: January 03, 2014, 04:21:00 pm
content: Quote from: gregtherider on January 03, 2014, 03:30:44 pmThat 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.

author: zapta
author_rank: Super Contributor
timestamp: January 03, 2014, 04:32:04 pm
content: Quote from: NANDBlog on January 03, 2014, 02:38:26 pmCan you explain?

author: jancumps
author_rank: Unknown
timestamp: January 03, 2014, 04:37:13 pm
content: It depends if your device is in scope for such criteria.Check the two standards I mentioned above for more info.

author: gregtherider
author_rank: Newbie
timestamp: January 03, 2014, 04:40:20 pm
content: Quote from: zapta on January 03, 2014, 04:32:04 pmI 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

author: tszaboo
author_rank: Super Contributor
timestamp: January 03, 2014, 05:42:47 pm
content: Quote from: gregtherider on January 03, 2014, 04:40:20 pmExactly. 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.

author: nctnico
author_rank: Super Contributor
timestamp: January 03, 2014, 05:46:16 pm
content: It also depends on the purpose of the circuit. The programming of a radio doesn't need to adhere to the MISRA rules.

author: dannyf
author_rank: Super Contributor
timestamp: January 03, 2014, 06:09:15 pm
content: QuoteIt 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.

author: Scrts
author_rank: Frequent Contributor
timestamp: January 19, 2014, 02:42:52 pm
content: We use Microchip PIC for small applications and Freescale for bigger ones. If DSP is needed, then TI.

author: Psi
author_rank: Super Contributor
timestamp: January 19, 2014, 11:41:58 pm
content: 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?

author: dannyf
author_rank: Super Contributor
timestamp: January 20, 2014, 12:08:17 am
content: QuoteOr 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.