nrf52832 S132 ble app gloable variable value loss in timer

[rc]

Hi:

I am using nrf52832 and I met a strange problem:

SDK version: nRF5_SDK_12.2.0_f012efa

---

---

First experiment(NO BLE):

using example peripheral/timer:

code change in main.c as the follows:

bool g_timer_Flag = true;

/**
 * @brief Handler for timer events.
 */
void timer_led_event_handler(nrf_timer_event_t event_type, void* p_context)
{
    static uint32_t i;
    uint32_t led_to_invert = ((i++) % LEDS_NUMBER);

    switch (event_type)
    {
        case NRF_TIMER_EVENT_COMPARE0:
            bsp_board_led_invert(led_to_invert);
			if(true == g_timer_Flag)
			{
				g_timer_Flag = false;
			}
            break;

        default:
            //Do nothing.
            break;
    }
}

then set a breakpoint at line g_timer_Flag = false;

debug perform normally enter breakline only once

---

---

Second experiment(Using BLE):

using example ble_peripheral/ble_app_uart

code change as the follows:

bool g_timer_Flag = true;

/**@brief Function for handling the data from the Nordic UART Service.
 *
 * @details This function will process the data received from the Nordic UART BLE Service and send
 *          it to the UART module.
 *
 * @param[in] p_nus    Nordic UART Service structure.
 * @param[in] p_data   Data to be send to UART module.
 * @param[in] length   Length of the data.
 */
/**@snippet [Handling the data received over BLE] */
static void nus_data_handler(ble_nus_t * p_nus, uint8_t * p_data, uint16_t length)
{
	ble_nus_string_send(&m_nus, p_data, length); //test send data back to nus app

	if(true == g_timer_Flag)
	{
		g_timer_Flag = false;
	}
    /*for (uint32_t i = 0; i < length; i++)
    {
        while (app_uart_put(p_data[i]) != NRF_SUCCESS);
    }
    while (app_uart_put('\r') != NRF_SUCCESS);
    while (app_uart_put('\n') != NRF_SUCCESS);
	*/
}

then set a breakpoint at line g_timer_Flag = false;

start debug:

the strange phenomenon happens: break happen every times I received a char from nus event

---

reason I guess:

1. RAM loss when user app finished because of softDevice memory strategy

2. program I write has bug (that's impossible )

3. Help me find it ,thank you very much!

---

[MartinBL]

I'm not sure if I understand your issue. You are expecting to hit the break point only once since g_timer_Flag is set to false after the first time? I'm not able to reproduce it. My breakpoint is only hit once even though I transfer several strings, or disconnect and reconnect before transmitting more strings.

Since nus_data_handler() is called from an interrupt context it might help to declare g_timer_Flag as 'volatile' though.

[rc]

I find that when the breakpoint hit for the first time,press continue, the ble will disconnect and the system restart, so, the value reset to init state true, can you reproduce?

[MartinBL]

You cannot debug while you have the softdevice enabled. If you stop at a breakpoint it will break your BLE link and the system will most likely reset. When your system resets in general, it is most likely because a function in your application asserts. Such asserts you can debug like this.