Communication between stm32 and raspberry pi4 through spi or i2c.

[suhfi]

Hello, I am doing a project with STM32F411RE NUCLEO board. I have downloaded the zip file from the web builder GRBLHAL. i have attached the file here. And I have successfully imported the zip folder onto the stm32cubeide. So for that project I want to add communication through SPI. and there is a SPI communication can be used for that project.

as in my previous query, i came to know that with UART communication, USB connector which is connected to cn1 of the board and raspberry pi USB connection - i am able to communicate. as i understood that, to communicate between raspberry pi  and stm32, i don't need to connect tx of pi -> rx of board, rx of pi -> tx of board, gnd to gnd. but can able to communicate through a connector. will that be possible with spi communication also. if no, then how can be the easy way to communicate between raspberry pi 4b and stm32f411re. and i forgot to mention that, in that file i am not able to find uart communication, i can only see the header files of spi, i2c, usb_device. can you please give me clarity over this ?

[SofLit]

Hello, 

Not clear: you need a communication with UART or SPI?

Related threads:

https://community.st.com/t5/stm32-mcus-embedded-software/uart-communication-between-raspberry-pi-4-and-stm32f411re/td-p/736436

https://community.st.com/t5/stm32-mcus-products/communication-between-nucleo-f411re-and-raspberry-pi-using-st/td-p/721443

[suhfi]

earlier i have done communication with uart, can i use the same connector or connections for spi also? if not how should i connect?

[SofLit]

So why the title mentions UART?

[Tesla DeLorean]

Why SPI?

Why can't you figure out what the issues are with USB/UART and fix/address those?

You have RPi side drivers that can do SPI simply?

Is the power supply or setup adequate to support the NUCLEO and everything else hung off it?

[Andrew Neil]

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@suhfi wrote:

as in my previous query

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These:

https://community.st.com/t5/stm32-mcus-embedded-software/uart-communication-between-raspberry-pi-4-and-stm32f411re/td-p/736436

https://community.st.com/t5/stm32-mcus-products/communication-between-nucleo-f411re-and-raspberry-pi-using-st/td-p/721443

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@suhfi wrote:

I have downloaded the zip file ?

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What zip file?

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@suhfi wrote:

 from the web builder GRBLHAL.

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The what??

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@suhfi wrote:

as i understood that, to communicate between raspberry pi  and stm32, i don't need to connect tx of pi -> rx of board, rx of pi -> tx of board, gnd to gnd. but can able to communicate through a connector.

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What do you mean by that?

Sure, you can always use a connector to make connections - it's in the very name!

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@suhfi wrote:

how can be the easy way to communicate between raspberry pi 4b and stm32f411re.

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You've already seen that you can do this with a UART link - either direct or via USB.

So what do you think is not "easy" about this?

What problem(s)/limitation(s) do you have that you think that SPI (or anything else) might solve?

I see no reason to believe that SPI is going to be any easier than UART. On the contrary, UART is very widely used and easy to test - so, if you're stuck with that, I can't see that you'll fare any better with anything else.

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@suhfi wrote:

in that file i am not able to find uart communication

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What file?

[suhfi]

okay, i think there is a misunderstanding of how things are explained here. yes, i have done communication with uart between both devices and it is working fine. i have a genuine doubt that with the connector can i communicate through spi, i2c same like uart?

[Andrew Neil]

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@suhfi wrote:

okay, i think there is a misunderstanding of how things are explained here. 

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Indeed - your posts are not very clear at all!

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@suhfi wrote:

 i have a genuine doubt that with the connector ...

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What "connector" are you talking about?

This one:

Check out the Raspberry Pi documentation to see what signals are available on that connector:

https://www.raspberrypi.com/documentation/computers/raspberry-pi.html#gpio-and-the-40-pin-header

You can clearly see that UART (TXD, RXD), SPI (MOSI, MISO, SCLK), and I2C (SDA, SCL) are all available on that connector, and documented on that page:

https://www.raspberrypi.com/documentation/computers/raspberry-pi.html#alternative-functions 

and 3rd-party sites; eg,

https://learn.sparkfun.com/tutorials/raspberry-pi-spi-and-i2c-tutorial/all

https://blog.adafruit.com/2022/02/04/the-raspberry-pi-4-has-more-spii2c-uart-ports-piday-raspberrypi-raspberry_pi/

[Andrew Neil]

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@Andrew Neil wrote:

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your posts are not very clear at all!

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@suhfi  One thing that would help would be to provide diagrams/pictures - so that we can actually see what you're taking about, rather than just rely on text.

Especially as there seems to be a bit of a language barrier.

[suhfi]

okay, thank you for the advice. i am gonna follow that. no i am not talking about the connector over there. i am talking about the usb connector. as in my previous discussion i came to know that usart via usb is possible between raspberry pi and stm32 nucleo board. i am wondering if usb connector supports i2c or spi just like uart?