transmit and receive messages using usart?

[avatar_ang]

Hello
I want to create sort of application that transmit and receive messages between 2 STM32F407 DISC0 and echo the transmited and received messages in PC screen(sort of chatbox)
any hints how can I do it?
and is it easier using USART or SPI?

[Andrew Neil]

Of course, transmitting and receiving messages is exactly what UARTs are for!

You will need:

1. One UART on each Disco board for the communication between boards;
2. One UART for the communication between the Disco board and PC
   (one UART on each board of you want both of the boards to be connected to a PC)

PS:

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@avatar_ang wrote:

and is it easier using USART or SPI?

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That depends on how familiar you are with SPI...

Connecting to a PC is certainly easier via UART.

[Hal3]

The simplest PC side would use UART to USB adapter cables and either  two Terminal programs in the PC or one terminal program in each of two PCs.

[Andrew Neil]

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@Hal3 wrote:

The simplest PC side would use UART to USB adapter cables 

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Simpler still: the VCPs in the ST-Links on the Disco boards.

Except that @avatar_ang seems to be using STM32F407G-DISC1  - where the VCP is not connected.

@avatar_ang if you're specifically wanting to do UART comms with PCs, it would make a lot more sense to choose a different board which does have a working VCP.

eg, NUCLEO-F411RE if you want to keep in the F4 family ...

[Hal3]

If the Chat application will be ultimately on a custom board and requires one PC with one connection, connect the two processors with a 485 bus using uart to 485 transceivers and connect the PC with a 485 to USB adapter. That will minimize ground problems and easily expand to more processors.