BlueNRG2 UART TX pullup

[rnone]

Hello,

While booting BlueNRG2, I was in need to externally pullup the UART TX output pin for proper operation.

The (post) boot initialization examples does not pullup the pin:

 /* Configure GPIO_Pin_8 and GPIO_Pin_11 as UART_TXD and UART_RXD*/

GPIO_InitStructure.GPIO_Pin = SDK_EVAL_UART_TX_PIN;

GPIO_InitStructure.GPIO_Mode = SDK_EVAL_UART_TX_MODE;

GPIO_InitStructure.GPIO_Pull = DISABLE;

Is there any reason ?

Thanks in advance.

Remy.

[Winfred LU]

Hi Remy,

The external pull-up is not required.

Please refer to schematic of STEVAL-IDB008v2

No external pull-up is added to BlueNRG-2 DIO8.

https://www.st.com/resource/en/schematic_pack/steval-idb008v2_schematic.pdf

Best Regards,

Winfred

[rnone]

Thanks Winfred,

I had the problem on a private design and BNRG-232. I switched to -248 and added pullups on my adaptor board.

I have not checked the IDB008v2 but isn't the BNRG uart connected to the internal stlink-acting chip ?

Anyway, I'll try to remove the pullups and will post the result.

Thanks for your time.

Remy.