# BX310X CTS/RTS flow control not available?

**URL:** <https://forum.sierrawireless.com/t/bx310x-cts-rts-flow-control-not-available/16644>\
**Category:** WiFi and Bluetooth Modules\
**Created:** [June 12, 2019, 9:30am UTC](https://forum.sierrawireless.com/t/bx310x-cts-rts-flow-control-not-available/16644 "2019-06-12T09:30:03Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Finze](https://avatars.discourse-cdn.com/v4/letter/f/3bc359/32.png) [@Finze](https://forum.sierrawireless.com/u/Finze)\
**Post date:** [June 12, 2019, 9:30am UTC](https://forum.sierrawireless.com/t/bx310x-cts-rts-flow-control-not-available/16644/1 "2019-06-12T09:30:03Z")

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Hi there,  
we’re still figuring out, how to communicate between micro controller and BX3105 via UART.  
It is working with a PC, but not with a micro controller yet… After sending AT commands to the BX3105 we don’t get a response, but after pressing the reset button, the micro controller receives a text.

Maybe we have to use flow control? For any reason, we can set the baud rate of the BX3105 but not flow control. The board is responding to “AT+IPR” but not to “AT+K” (it always shows ERROR), tried it at baud rates of 9600 and 115200… Also AT+K doesn’t show up in the list of available commands (AT+CLAC) but with our Firmware revision (1.3) it should be there.

Any ideas why AT+K is not working or other approaches how to implement the UART communication?

Thanks!

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**Author:** ![Finze](https://avatars.discourse-cdn.com/v4/letter/f/3bc359/32.png) [@Finze](https://forum.sierrawireless.com/u/Finze)\
**Post date:** [June 12, 2019, 9:48am UTC](https://forum.sierrawireless.com/t/bx310x-cts-rts-flow-control-not-available/16644/2 "2019-06-12T09:48:43Z")

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> [@Finze](#):
>
> Also AT+K doesn’t show up in the list of available commands (AT+CLAC) but with our Firmware revision (1.3) it should be there.

Update: AT+K is in the list of available commands, just oversaw it. But the BX3105 always responds with an ERROR

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**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/jyijyi/32/4766_2.png) [@jyijyi](https://forum.sierrawireless.com/u/jyijyi)\
**Post date:** [June 12, 2019, 9:58am UTC](https://forum.sierrawireless.com/t/bx310x-cts-rts-flow-control-not-available/16644/3 "2019-06-12T09:58:56Z")

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how about using at&k?

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**Author:** ![Finze](https://avatars.discourse-cdn.com/v4/letter/f/3bc359/32.png) [@Finze](https://forum.sierrawireless.com/u/Finze)\
**Post date:** [June 13, 2019, 6:09am UTC](https://forum.sierrawireless.com/t/bx310x-cts-rts-flow-control-not-available/16644/4 "2019-06-13T06:09:47Z")

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Thanks! That issue was easy to fix