The radio_test application doesn't receive input on nrf52840 chip, while the echo_bot example does.

[xiongwei.wang]

I encounter this problem:

The radio_test application works correctly on the official nrf52840dk board, but cannot receive input commands on my custom product board.

However, the echo_bot example works fine on the same custom board.

I tried adding the following configuration:

```conf

CONFIG_CONSOLE=y
CONFIG_SERIAL=y
CONFIG_UART_CONSOLE=y
CONFIG_SHELL_BACKEND_SERIAL=y

```

I also tried to disable hardware flow control in code:

```c

    nrf_uarte_hwfc_pins_disconnect(NRF_UART0);

```

I noticed that echo_bot doesn't disable hardware flow control but still works properly.

My product uses the nRF52840 chip connected through an external J-Link, and I'm using NCS v2.9.0.

Questions: What should I do? What configuration or code do I need to add to solve this problem?

[Susheel Nuguru]

Wang, I just took this thread and I will try to look into it and comeback to you by tomorrow evening with my observations. Thanks for your patience.

[xiongwei.wang]

I think I found the specific problem, I tried to install nRF5 SDK to run the radio test, and I dicovered it gets stuck at following code:

/** @brief Function for configuring all peripherals used in this example.
 */
static void clock_init(void)
{
    // Start 64 MHz crystal oscillator.
    NRF_CLOCK->EVENTS_HFCLKSTARTED = 0;
    NRF_CLOCK->TASKS_HFCLKSTART    = 1;

    // Wait for the external oscillator to start up.
    while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0)
    {
        // Do nothing.
    }
}

I searched in the forums and saw many people get stuck here due to crystal issues.Since I have limited knowledge about hardware, I need to confirm whether this is a hardware issue about our board.Thanks everyone, especially Nugruru.