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Posts: 10
Registered: ‎04-27-2006

BT121: Indication of Data available for Host MCU

Hi,

 

I am considering to use BT121 via BGAPI. The Host is STM32F4 MCU.

Hardware connection to the module RX\TX,CTS\RTS.

 

My MCU using ST "Stop" mode to save power. In this mode the UART of the MCU is not working.

And it is wakes-up by RTC interrupt every 10ms.

 

Question1:

Is BT121 have any mechanism to wake-up my MCU before send me resp. or event data via UART.

Some i/o that i can use as input to my MCU to wake-up my MCU from "Stop" mode.

 

Quaestion2:

In case of Quastion1 answer is negative.

What happens in BT121 firmware if i deactivate its CTS input (output i/o from my MCU) .

Will it (BT121 firmware) send rsp. or event packets to my MCU during the time its CTS input deactivated ?

Any timeout on this pin,before data (that is ready to be sended to my MCU)  is dropped ? 

 

 

 

 

Posts: 332
Registered: ‎09-29-2015

Re: BT121: Indication of Data available for Host MCU

Hello - The answer to your question 1 is simple: yes, this mechanism exists. In fact, please consider the option <host_wake_up port="x" pin="x" /> that you can enter into your hardware.xml project file: with that option you can indeed configure a module's output pin that will be automatically asserted when the module is about to send events or responses or data over the UART to host MCU - Best regards.

Posts: 10
Registered: ‎04-27-2006

Re: BT121: Indication of Data available for Host MCU

Thanks,

 

Do you know what time i have (my MCU) for wake-up. I mean after BT121 asserts the "host_wake_up" pin

is there any delay before it starts to send data via uart or BT121 relates on RTS\CTS control pins ?

Posts: 332
Registered: ‎09-29-2015

Re: BT121: Indication of Data available for Host MCU

There is no delay after the BT121 asserts the "host_wake_up" pin: data transfer from module to host MCU over UART will happen immediately after the "host_wake_up" pin is asserted, depending of course if the flow control's current status allows it.