unable to use ble_uart using nrf52810

[_bhanu]

Hi,

I'm using app_ble_uart  example using nrf52810 for nrf52810 UART RX &  TX  pins are (P0.15 - P0.14)  while configuring using i got a problem with RX transmission ,when i changed to  Rx pin as p0.15  the nrf52810 module is not working.

[Einar Thorsrud]

Hi,

I have some questions:

• In what way does it not work?
• Can you explain in detail how you changed the pin, perhaps by uploading a diff of your code compared to the SDK example?
• Also, which module do you have and how do you use it (anything particular with P0.15, for instance)?
• Which SDK are you using)?

[_bhanu]

1. I'm using ble_app_uart example  using NRF52810  custom board  and nRF5_SDK_17.1.0_ddde560. IN SDK  config  i just changed the RX and TX pins  to (P0.15 & P0.14)   after  upload the coded to NRF52810 custom board  the custom board not working like its not  going to "powered on" .

If i just change only (TX pin to  P0.14)  NRF52810 module  is going to powered on its advertising the ble and it only transmitting the data .when if i change  RX pin  also even the NRF52810 module not going to powered on .

Here i changed the TX and RX pin in my code

static void uart_init(void)
{
    uint32_t                     err_code;
    app_uart_comm_params_t const comm_params =
    {
        .rx_pin_no    = 15,
        .tx_pin_no    = 14,
        .rts_pin_no   = RTS_PIN_NUMBER,
        .cts_pin_no   = CTS_PIN_NUMBER,
        .flow_control = APP_UART_FLOW_CONTROL_DISABLED,
        .use_parity   = false,
#if defined (UART_PRESENT)
        .baud_rate    = NRF_UART_BAUDRATE_115200
#else
        .baud_rate    = NRF_UARTE_BAUDRATE_115200
#endif
    };

    APP_UART_FIFO_INIT(&comm_params,
                       UART_RX_BUF_SIZE,
                       UART_TX_BUF_SIZE,
                       uart_event_handle,
                       APP_IRQ_PRIORITY_LOWEST,
                       err_code);
    APP_ERROR_CHECK(err_code);
}

[Einar Thorsrud]

Hi,

There is nothing special about P0.14 and P0.15, so we must look further to understand what is happening. Tw0 important questions:

1. Do you use any of the two pins for anything else in your firmware?
2. How are this pins connected physically on your HW?
   1. For instance, by setting P0.15 to Tx that will be default high as that is the idle state of UART pins. Could that cause problems with your HW?

_bhanu said:

not working like its not  going to "powered on" .

What exactly do you mean by this? Have you debugged to see which state the device is in?

[_bhanu]

HI,

Einar Thorsrud said:

Do you use any of the two pins for anything else in your firmware?

I didn't use those pins for any other purpose i only only used for TX & RX in my firmware.

Einar Thorsrud said:

How are this pins connected physically on your HW?

i connected TX pin of HW connected to  FTDI to see weather the communication happens or not.

Einar Thorsrud said:

What exactly do you mean by this? Have you debugged to see which state the device is in?

when i mention RX pin as P0.15  the ble was not advertising and moreover  which data i given to transmit  is also not doing. this problem I'm facing only  when i mention RX pin as P0.15   

[Einar Thorsrud]

_bhanu said:

i connected TX pin of HW connected to  FTDI to see weather the communication happens or not.

Can you share your schematics so that we can see if those pins are also connected to something else?

_bhanu said:

when i mention RX pin as P0.15  the ble was not advertising and moreover  which data i given to transmit  is also not doing. this problem I'm facing only  when i mention RX pin as P0.15   

That is quite high-level, then. Have you tried to debug? What does that tell you? Are any APP_ERROR_CHECK's hit or something else?

[_bhanu]

Einar Thorsrud said:

happens or not.

Einar Thorsrud said:

That is quite high-level, then. Have you tried to debug? What does that tell you? Are any APP_ERROR_CHECK's hit or something else?

 i already tried  so, many times  to debug but i didn't get any data while debugging  

[Einar Thorsrud]

Hi,

I do not see anything obviously problematic in the schematic. 

_bhanu said:

 i already tried  so, many times  to debug but i didn't get any data while debugging  

As long as the device is powered and nothing messes with the SWD lines, you should be able to get something out of the debugger. Can you explain how you debug and what you find (how little it may be)? By explaining (and showing) the issues you have while debugging in more detail, perhaps I can suggest what you can do to get around those problems. I assume you are able to erase and re-program the device? If so, the debug interface is working. Debugging must work in order to develop and test in any meaningful way, and debugging is  only sensible way to move forward.

[_bhanu]

Hi,

i have a question is it required to pullup the  RX pin in Custom board  to work on that

[Einar Thorsrud]

Hi,

You need to ensure that the inputs are not floating. If the UART lines are always connected to another device on the board, and this always drives the input lines to the nRF ( Rx and optionally CTS), then there is no need for pullup(s). If not, you can enable the internal pullup. See this post.

[_bhanu]

Hi,

Hear my UART lines  TX and RX are connected to "QUECTEL" module  when the Quectel module is on  nRF device working fine, when i turned of the Quectel module which is connected to UART  then nRF is also going to turn off automatically. 

[Einar Thorsrud]

Hi,

I see. Then there should not be a need for any pull resistors (and if you double-check and see that in some corner cases the inputs are floating, you can always just enable internal pullups on the nRF).