RESC: Automotive quality high voltage fork from the VESC

Discuss hardware related to the VESC such as the NRF nunchuk.
rew
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Joined: 25 Mar 2016, 12:29
Location: Delft, Netherlands.

Re: Moving around pins on the STM32 and upgrading to f7 over f4

Postby rew » 04 Jun 2017, 04:55

NORMALLY ST provides compatibility between series of chips. So I have a board, where I was able to upgrade the planned '072 to a '405 without any hassle. Similarly, I have an application that I can prototype using the VESC hardware but that doesn't need a big CPU. So I suddenly have an '072 on there....

However, with the 100 pins STM32F7xx vs the STM32F4xx something went wrong with the 100-pin package.

Pin 19, VDD on the '405 is not present on the F7. And pin 49, VSS on the F7 is not present on the F4. And all thirty pins in between are shifted by one position.

So, in general, you would be able to design a board for either F4 or F7, but the exception is the 100 pin variant....

ragonamuffin
Posts: 37
Joined: 04 Apr 2017, 02:08
Location: CT, USA

Re: Moving around pins on the STM32 and upgrading to f7 over f4

Postby ragonamuffin » 04 Jun 2017, 16:54

Just my luck! :lol: I think I will build my first prototype out of the F4 as I am still a newbie and i don't want to run into too many issues. I will post my revised schematics here shortly. Stay tuned!

Thanks as always!

rew
Posts: 940
Joined: 25 Mar 2016, 12:29
Location: Delft, Netherlands.

Re: Moving around pins on the STM32 and upgrading to f7 over f4

Postby rew » 04 Jun 2017, 18:01

Well.. If you make a proper footprint of the F4 and F7 chips, they should "fit" in the schematic. So then you get to swap out the CPUs, and have only minor adjustments to make in the PCB. (provided your CAD package does forward/backward annotation).

ragonamuffin
Posts: 37
Joined: 04 Apr 2017, 02:08
Location: CT, USA

Re: Moving around pins on the STM32 and upgrading to f7 over f4

Postby ragonamuffin » 06 Jun 2017, 20:03

rew wrote:NORMALLY ST provides compatibility between series of chips. So I have a board, where I was able to upgrade the planned '072 to a '405 without any hassle. Similarly, I have an application that I can prototype using the VESC hardware but that doesn't need a big CPU. So I suddenly have an '072 on there....

However, with the 100 pins STM32F7xx vs the STM32F4xx something went wrong with the 100-pin package.

Pin 19, VDD on the '405 is not present on the F7. And pin 49, VSS on the F7 is not present on the F4. And all thirty pins in between are shifted by one position.

So, in general, you would be able to design a board for either F4 or F7, but the exception is the 100 pin variant....


So, basically I should move up to the larger pinout? I can likely fit that processor on my controller PCB thanks to all the high power stuff that will need lots of space anyways.

rew
Posts: 940
Joined: 25 Mar 2016, 12:29
Location: Delft, Netherlands.

Re: Moving around pins on the STM32 and upgrading to f7 over f4

Postby rew » 06 Jun 2017, 21:05

Oh, sure. the 144 pin version should work. Or otherwise the 176 pin version if the 144 pin version doesn't work. Eighty unused pins! whow! (probably only about 64, as the number of ground and VCC pins grows slowly as well. An you slowly get a few more special purpose pins. Like VDDA and VREF are the same pin on small packages, but separate pins on bigger ones).

ragonamuffin
Posts: 37
Joined: 04 Apr 2017, 02:08
Location: CT, USA

Re: Moving around pins on the STM32 and upgrading to f7 over f4

Postby ragonamuffin » 06 Jun 2017, 21:31

What about using one of these, as I really would prefer 3 CAN buses:
STM32F413VG
STM32F413VH
STM32F423VH
STM32F423RH
STM32F413RH
STM32F413RG

If not one of these, which 144 pin would be the least troublesome?

ragonamuffin
Posts: 37
Joined: 04 Apr 2017, 02:08
Location: CT, USA

Re: Moving around pins on the STM32 and upgrading to f7 over f4

Postby ragonamuffin » 06 Jun 2017, 23:08

Prevas_erra wrote:why not select a 3.3V CAN chip.
Eric


I didn't even realize that :shock:
I would have dead pins at best right off the bat, thanks for spotting that!

How about one of these:

SN65HVD233-Q1
SN65HVD235-Q1

I don't really understand the benefit of each one, but either should work.... but that is what I said with that last CAN transceiver :lol:

ragonamuffin
Posts: 37
Joined: 04 Apr 2017, 02:08
Location: CT, USA

Re: Moving around pins on the STM32 and upgrading to f7 over f4

Postby ragonamuffin » 06 Jun 2017, 23:10

Looks like I only need to supply 3.3v to this PCB now! This PCB is going to be squeaky clean :) 12v of course for gate drivers.

EDIT: Nevermind, using 5v on the current amps, oh well have to add an extra wire to harness :lol:

rew
Posts: 940
Joined: 25 Mar 2016, 12:29
Location: Delft, Netherlands.

Re: Moving around pins on the STM32 and upgrading to f7 over f4

Postby rew » 07 Jun 2017, 05:48

ragonamuffin wrote:What about using one of these, as I really would prefer 3 CAN buses:
STM32F413VG
STM32F413VH
STM32F423VH
STM32F423RH
STM32F413RH
STM32F413RG

If not one of these, which 144 pin would be the least troublesome?

The 411, I know is a cheaper F4-class CPU. I investigated if I could use it, but again: Not without a significant software-development penalty: That one has only 1 ADC instead of the three of the F405. I looked it up for you the F413 and F423 only have one ADC: won't work.

Secondly after the F4xx you list the letters V and R: V means 100 pins. R means 64 pins. None of these have 144pins.

The last letter, The G or H means that it has 1 or 2M of memory. (or at least the amount of flash memory if I didn't get the numbers right).

Look for an STM32F405Zxxx CPU. That's 144 pins. Design your board for that, secure a few CPUs for your test boards, make sure the software works, and THEN see if you can find something else that fits.

ragonamuffin
Posts: 37
Joined: 04 Apr 2017, 02:08
Location: CT, USA

Re: Moving around pins on the STM32 and upgrading to f7 over f4

Postby ragonamuffin » 07 Jun 2017, 14:02

That sounds like a great plan. I was hoping to have found a 64 pin 3 CANbus chip that would work. I will move forward with the 144 pin!


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