STM32 UART connecting RxD and TxD pin (pin, not internl line)

[JuM]

Posted on June 06, 2017 at 15:33

Hi, want to build a 'uart daisy chain' with several (up to 200) STM32 MCUs by connecting TxD of uart number n to RxD of uart number n+1 (1-wire connection). To perform Initial addressing Job I'm thinking to do it like the old TMP104 (temperature sensor of TI) did. For this I would need to get RxD and TxD pin of UART of STM32 be connected/disconnected.

I am aware of the 'half duplex mode' (HDSEL:=1). But this mode is not useable, as it disconnects the RxD pin.Any way to get RxD and TxD connected and disconnected by software (without additional hardware external to STM32? Best regards, Juergen.

[Tesla DeLorean]

Posted on June 06, 2017 at 17:35

>>

Any way to get RxD and TxD connected and disconnected by software (without additional hardware external to STM32?

Not that's immediately apparent to me. Simple enough to do with external interface logic.

Do the feed-thru in software?

[JuM]

Posted on June 07, 2017 at 08:33

Feed-thru in Software adds one character delay at every MCU which is totally unuseable for our case.

[Tesla DeLorean]

Posted on June 08, 2017 at 02:44

So handful of NAND gates, job done