STM32WB55 IrDA hardware setup

[Tvan .15]

after looking over all the documentation i could find (datasheet, reference manual, etc.), i could not clearly find how i am meant to connect IR LED(s) for IrDA communication with an STM32WB55. The image i attached is a screenshot from the reference manual, which implies that there may be IrDA_OUT and _IN pins (i'm interpreting this as being seperate from the TX and RX pins). Am i supposed to add some kind of intermediate IC for IrDA, or can the STM32WB55 actually output signals for driving/reading IR LEDs/photodiodes?

 

P.S. i'm aware of the existance of the IR_OUT pins, but that appears to be its own seperate thing. In the IR_OUT documentation they use only timers (TIM16 & TIM17), not the USART peripheral.

[MM..1]

Yes not clean , but i mean TX and RX is changed into IR after HAL IRDA init ...

[Peter BENSCH]

IrDA has hardly been used for a long time, which is also noticeable in discontinued IrDA transceivers. However, since essentially everything except the TIA and optical components is included in the STM32 IrDA SIR ENDEC, it is possible to recreate IrDA with

• an IR LED plus driver transistor and
• an IR photodiode plus TIA.

As @MM..1​  said, RX and TX are switched to the IrDA function so that LED driver and TIA can be connected directly.

Regards

/Peter

[Tvan .15]

alright, thank you!