Search found 7 matches

by Sync
Sun Feb 15, 2015 5:11 pm
Forum: Misc
Topic: Is stm32f4 the right chip?
Replies: 91
Views: 14371

Re: Is stm32f4 the right chip?

Well, I think the takeaway is that rusEFI needs a more closer to the hardware implementation, at least for the position capture. It does not matter which MCU it is in the end, but the question rather is if you really want to use one that has no community support (as in actual opensource community). ...
by Sync
Thu Feb 12, 2015 1:27 pm
Forum: Hardware
Topic: external ADC
Replies: 29
Views: 4474

Re: external ADC

I guess we could just daisychain the external ADCs and use DMA as abecedarian said. That way the ADC is running completely alone without robbing computational power. The software just looks at the right place for the values and does what it needs to do. Can't we just use the internal ADC? We have 16...
by Sync
Mon Feb 09, 2015 1:52 pm
Forum: Misc
Topic: Is stm32f4 the right chip?
Replies: 91
Views: 14371

Re: Is stm32f4 the right chip?

Here is a good reference on interrupt latency on the STM32: http://community.arm.com/docs/DOC-2607 Interrupt latency will be fairly predictable and you can prioritize them appropiately that spark holds good accuracy. Once you are synchronized, inter-rev speed is not going to change. I don't see why ...
by Sync
Sun Feb 08, 2015 5:57 pm
Forum: Misc
Topic: Is stm32f4 the right chip?
Replies: 91
Views: 14371

Re: Is stm32f4 the right chip?

That would be 44 cycles when running at 168MHz. Are you sure that you are running at full speed? @russian: Yeah, that wasn't meant as a negative comment, just my experience with latency issues. I have to look deeper into the actual code to get a feeling for what is happening. I just had a quick glan...
by Sync
Sun Feb 08, 2015 2:41 pm
Forum: Misc
Topic: Is stm32f4 the right chip?
Replies: 91
Views: 14371

Re: Is stm32f4 the right chip?

I think the latency issue is rooted in the RTOS, for a position controller project I had to give up ChibiOS because I could not process ADC data in an interrupt over a few kSPS. Maybe the discussion should be more in the direction of whether we should try to go to a more event driven framework than ...
by Sync
Sat Feb 07, 2015 5:22 pm
Forum: Misc
Topic: Is stm32f4 the right chip?
Replies: 91
Views: 14371

Re: Is stm32f4 the right chip?

Well, the toolchain might be free now with the implications of a code size of 16K max from what I can understand, that part is not clear. But how does that change in the future? If at some point TI chooses to lock down the licensing development is suddenly impossible for people without the old tools...
by Sync
Sat Feb 07, 2015 2:44 pm
Forum: Misc
Topic: Is stm32f4 the right chip?
Replies: 91
Views: 14371

Re: Is stm32f4 the right chip?

It might sound a bit rude as the first post, but why do you think that there is a need to switch to a 5V controller? A lot of the currently deployed automotive controller platforms run on a single 3.3V supply mostly due to speed or cost considerations. It is much cheaper to buy a already proven sili...