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Control 5 SPI devices with the STM32F722RET6

raspdroid
Associate II

Hello,

It's possible to control 5 SPI devices with the STM32F722RET6? LQFP-64

Best regards

6 REPLIES 6

Do they actually need unique interfaces?

Some SPI can use a GPIO as CS (Chip Select), and disconnect MISO when inactive.

You might also be able to use a 3-to-8 decoder to save pins wrt CS for multiple devices.

You could walk the datasheet and see if you can instantiate 5 separate SPI, or use CubeMX.

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Hello,

In one I can use UART.

But in the others I need to use SPI.

I have two SPI sensor mems and one dual/quad SPI and QPI flash memory and one SPI OSD.

Can I use any pin for the SS/CS selector chip?

0690X00000Arv2FQAR.png

QSPI has fixed/committed pins for NCS, common CLK between Bank1/Bank2

64-pin is quite limiting

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Yes, any GPIO pin can be used as CS#/NSS (for normal SPI, not QPI), and one SPI controller can serve as many peripherals as you want this way. Don't enable the Hardware NSS Signal.

Be careful at the end of the transmission, don't set the pin high too early. Read the Procedure for disabling the SPI section in the reference manual on when it's safe to do it.

raspdroid
Associate II

Good morning,

Thanks for the replies,

So I'm going to use so:

SPI1 for the two sensor mems and two gpio for the CS#

SPI2 for the SPI flash memory

SPI3 for the OSD

BR

Yes, I have not space, 20x20 mm board

I'm going to use SPI, not QSPI