Reasons to switch from STM32F746NGH6 to STM32H750XB in the context of a scientific application with HMI

[AMugn.910]

Hi,

A few days ago, I've asked the community about its opinion on the use of TouchGFX and FreeRTOS for developing a scientific instrument with HMI. Thank to you for all your suggestions which brought new concepts to our project.

I come back to you to get your opinion on the choice of the MCU. The MCU has no heavy calculation to perform in our case, but a lot of I/O are necessary for allowing it to interact with the different sensors and actuators of the instrument. For this application, we have chosen a STM32F746NGH6 (release 2015), which has enough I/O and power for managing HMI and all of our sensors/actuators. We plan to use a 32F746GDISCOVERY for development.

Another member of this community suggested to have a look to the H7 series, which is newer and faster than the F7. I've spotted that the STM32H750XB (release 2019)  appears to be an "improved" version of the STM32F746NGH6, with higher power and more features, while being two times cheaper (8€ per unit for the F7 vs 4.5€ per unit for the H7). It also has a dev board : the STM32H750B-DK .

Reliability is very important in our project. In my opinion, the only reason we should stay with the STM32F746NGH6 is that the MCU is 5 years old and has proven to be reliable. But I'm not even sure if the age of the MCU is a real factor of reliability.

Could you please give me your opinion on that, should we switch for the STM32H750XB ?

link to original thread : https://community.st.com/s/question/0D53W000007WQFISA4/some-software-choices-to-make-for-a-young-company-project

Thanks,

Antoine

[waclawek.jan]

Benchmark.

Probably the most computing-power (and system resources if you intend to use LTDC) demanding element of your proposed design is the 800x480 display. AFAIK Disco boards for those two families don't have that resolution; try to find a devboard which has.

*All* chips have their quirks, some of them surfacing after a long time in a particular setup.

JW

PS. You should've linked in the original thread, and/or give review of the intended purpose/features.

[Tesla DeLorean]

https://community.st.com/s/question/0D53W000007WQFISA4/some-software-choices-to-make-for-a-young-company-project

[AMugn.910]

Sorry I forgot

[Tesla DeLorean]

The H7 has a newer version of the CM7 core, without some of the earlier debugger/single-step issues, the H7 also uses the higher precision FPU-D, ie supports 64-bit and 32-bit floating point, not just 32-bit ones supported by the FPU-S in the F746

There is a Value Line version F750 (like F746/756) and F730 (F722/F732) https://www.st.com/en/microcontrollers-microprocessors/stm32f7x0-value-line.html

Remember the Value Line parts have less tested Internal Flash, but use the same die. Will your design use external QSPI Flash?

The H7 has more Internal RAM, faster/wider eMMC/SD-Card support

[AMugn.910]

I was planning to use external QSPI flash, I do not yet know the total size that will be taken by our HMI primitives. Using 800x480 resolution, I'm not sure that 2Mbytes of internal flash will be enough. I see all series have 1 Mbyte of RAM, so I suppose it is enough to hold 1 framebuffer.

[waclawek.jan]

> I see all series have 1 Mbyte of RAM, so I suppose it is enough to hold 1 framebuffer.

That memory may be fragmented. Read the RM.

JW