nrf51822 event on_ble_write

[james tech]

hi nordic;

i need your help, i'm trying to code a control of gpio over the BLE i have an app on android with it i can establish connection and see the service and charactrestic but the problem that i have, is with event on_ble_write i want juste change the state of the pin 20 on my nrf51822 pca20006 just after receiving any kind of data but it didin't work .

to recap the idea of the code attached i have function returnei returnes a variable ii after sending some data from smartphone to nrf over ble this variable intially is at value 2 after sending the data its value will be at 0 and the pin 20 will be at low state but unfortunately this didn't work

any help from you will be appreciated

main.c

our_service.c

our_service.h

[MartinBL]

In on_ble_write() there is an if/else statement that checks whether you are writing to your characteristics CCCD handle or your value handle. You wan't to update your ii variable in the case you write to your value_handle. You only write to the CCCD handle when you update the notification/indication settings.

[james tech]

now i updated my ii in both cases but the 20 pin is still without any change

static void on_ble_write(ble_os_t * p_our_service, ble_evt_t * p_ble_evt)
{
    // Declare buffer variable to hold received data. The data can only be 32 bit long.
    uint32_t data_buffer;
    // Populate ble_gatts_value_t structure to hold received data and metadata.
    ble_gatts_value_t rx_data;
    rx_data.len = sizeof(uint32_t);
    rx_data.offset = 0;
    rx_data.p_value = (uint8_t*)&data_buffer;
    
    // Check if write event is performed on our characteristic or the CCCD
    if(p_ble_evt->evt.gatts_evt.params.write.handle == p_our_service->char_handles.value_handle)
    {
				ii=0;
        // Get data
        sd_ble_gatts_value_get(p_our_service->conn_handle, p_our_service->char_handles.value_handle, &rx_data);
        // Print handle and value 
        printf("Value received on handle %#06x: %#010x\r\n", p_ble_evt->evt.gatts_evt.params.write.handle, data_buffer);
			  
    }
    else if(p_ble_evt->evt.gatts_evt.params.write.handle == p_our_service->char_handles.cccd_handle)
    {
        // Get data
			ii=0;
        sd_ble_gatts_value_get(p_our_service->conn_handle, p_our_service->char_handles.cccd_handle, &rx_data);
        // Print handle and value 
			
        printf("Value received on handle %#06x: %#06x\r\n", p_ble_evt->evt.gatts_evt.params.write.handle, data_buffer);
        
			if(data_buffer == 0x0001)
        {
            printf("Notification enabled\r\n");
				//	ii=0;
        }
        else if(data_buffer == 0x0000)
        {
            printf("Notification disabled\r\n");
				//	ii=1;
        }
    }
}

[MartinBL]

1. Have you debugged your code and checked whether on_ble_write() is being called and whether ii is being updated?
2. What SDK are you using?
3. Try to declare ii as 'volatile'.

[james tech]

thank you the problem is with the nature of the variable I must declare it volatile