Error 133 (0x85): GATT ERROR with custom service tutorial

[RO]

Hello,

I am new to the Nordic Environment. I am following the excellent tutorial to create a custom service and characteristic.

Everything worked fine until Step 6(Handling the Write event from soft device). 

However, after working on Step 7 & 8(Propagating Custom Service Events to Application and Notifying the Custom Value Characteristic), I get Error 133: GATT ERROR on the nRF Connect app (on a One Plus 5) when I try to connect to the advertised label. 

I have read the other posts related to this issue but can't my sense of them with respect to my case.  What could be the reason for sudden occurrence of this error?

Please help.

Thanks

[RO]

bjorn-spockeli I have followed your excellent tutorial on developing a custom service. However as soon as I invoke the event handler from ble_cus.c by calling p_cus->evt_handler(p_cus, &evt), I get a GATT ERROR when trying to connect from the app. What could be happening? I would greatly appreciate your help. Thanks

[bjorn-spockeli]

Hi RO, have you added the line that sets on_cus_evt as the event handler in services_init() as shown below?

        // Initialize CUS Service init structure to zero.
        ble_cus_init_t      cus_init = {0};

        // Set Custom Service Event handler
        cus_init.evt_handler                = on_cus_evt;
    
        BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cus_init.custom_value_char_attr_md.cccd_write_perm);
        BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cus_init.custom_value_char_attr_md.read_perm);
        BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cus_init.custom_value_char_attr_md.write_perm);
    
        err_code = ble_cus_init(&m_cus, &cus_init);
        APP_ERROR_CHECK(err_code);

[RO]

Yes I did. the error still appears. For the time being, I am invoking the event handler in on_write() function only, and it works. But it doesn't work when I invoke it in the on_connect() function. 

[Leon678]

cccd_md.write_perm = p_cus_init->custom_value_char_attr_md.cccd_write_perm;

Did you add this line to the custom_value_char_add() function in ble_cus.c

[bjorn-spockeli]

Can you post the on_cus_evt function? And can you set a breakpoint in on_cus_evt and see if you enter it when you connect and call the event handler in the on_connect function?

[RO]

I set a breakpoint in on_cus_evt. It enters the on_write function in blle_cus.c but it does not enter the on_cus_evt function in main.c. I get an 'Unknown function at some address'.

Here is the code of on_cus_evt:

static void on_cus_evt(ble_cus_t     * p_cus_service,
                       ble_cus_evt_t * p_evt,
                       ble_evt_t const * p_ble_evt_main)
{
    
    switch(p_evt->evt_type)
    {
        
        case BLE_CUS_EVT_WRITE:

            printf("%s"," write to sd card ");
            break;
            
        case BLE_CUS_EVT_NOTIFICATION_ENABLED:
            break;

        case BLE_CUS_EVT_NOTIFICATION_DISABLED:
            break;
        
        
        case BLE_CUS_EVT_CONNECTED:
            break;

        case BLE_CUS_EVT_DISCONNECTED:
              break;

        default:
              // No implementation needed.
              break;
    }
}

[bjorn-spockeli]

WHich address is it referring to? Could you check the .map file and see where on_cus_evt has been placed by the linker? 

[RO]

It's referring to 0x000008C8.

This is what I see in the .map file:

".text.on_cus_evt
0x000000000002bfa4 0x18 Output/ble_app_template_pca10040_s132 Release/Obj/main.o"

I have attached the .map file just in case for reference.

ble_app_template_pca10040_s132.map

[bjorn-spockeli]

0x000008C8 is the MemoryManagement_Handler, so it means that you've attempted to jump to an invalid address. Can you check if the function pointer p_cus->evt_handler points to the correct address, i.e. 0x2bfa4 when you call  p_cus->evt_handler(p_cus, &evt); in on_connect()?