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AN2606 RS232 (presumed dumb question)

Associate II
Posted on October 11, 2013 at 13:25


If I had a suitable board, I'd just try the obvious, but I don't presently have one. I'm pretty darned sure this is a dumb question, but if I'm wondering, I guess others may do as well, so here goes.

In AN2606, it repeatedly says:

''RS232 serial interface (example, ST3232 RS232 transceiver) has to be directly linked to the USART''

I presume this is badly worded in that they do NOT mean connect the RS232 interface directly to the STM32, they mean that the TTL-compatible side of, e.g. an ST3232 transceiver, should be connected to the STM32.

I.e., any voltage compatible UART/USART serial lines like from another STM32 series device should fine.

Posted on October 11, 2013 at 14:55

The pins of the STM32 can connect directly to any other CMOS compatible interface, say other board level micro, GPS, Modem, etc.

To connect to RS232 level external interface you'll need a transceiver (inferred two way translation)
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Associate II
Posted on October 11, 2013 at 17:03

That's as I believed it would be.

V24 signals direct to the chip would sound a bad idea when the pins are not _that_ voltage tolerant.

So .. a badly worded document, then.

Thanks for confirming that, Clive.