Hi there,
I am having a hard time with some C pointers to add a new BLE Characteristic.
I would like to have a function that returns a simple characteristic metadata and attribute value, given some parameters:
static void getUnsecureCharacteristic(ble_gatts_char_md_t *char_md, ble_gatts_attr_t *char_value, uint8_t read, uint8_t write, uint8_t notify, uint32_t uuid) {
uint32_t err_code;
ble_gatts_attr_md_t cccd_md;
ble_uuid_t ble_uuid;
ble_gatts_attr_md_t attr_md;
//Memset needs pointer, no need to dereference it here
memset(char_md, 0, sizeof(*char_md));
char_md->char_props.read = read;
char_md->char_props.write = write;
char_md->char_props.notify = notify;
char_md->p_char_user_desc = NULL;
char_md->p_char_pf = NULL;
char_md->p_user_desc_md = NULL;
char_md->p_cccd_md = NULL;
char_md->p_sccd_md = NULL;
memset(&attr_md, 0, sizeof(attr_md));
ble_srv_cccd_security_mode_t secMode;
attr_md.read_perm = secMode.read_perm;
attr_md.write_perm = secMode.write_perm;
attr_md.vloc = BLE_GATTS_VLOC_STACK;
attr_md.rd_auth = 0;
attr_md.wr_auth = 0;
attr_md.vlen = 0;
ble_uuid.type = 0x02;
ble_uuid.uuid = uuid;
memset(char_value, 0, sizeof(*char_value));
char_value->p_uuid = &ble_uuid;
char_value->p_attr_md = &attr_md;
char_value->init_len = sizeof(uint8_t);
char_value->init_offs = 0;
char_value->max_len = sizeof(uint8_t);
}
Then I can call my function from outside:
static uint32_t custom_value_char_add(ble_cus_t * p_cus, const ble_cus_init_t * p_cus_init)
{
uint32_t err_code;
ble_gatts_char_md_t char_md;
ble_gatts_attr_md_t cccd_md;
ble_gatts_attr_t attr_char_value;
ble_uuid_t ble_uuid;
ble_gatts_attr_md_t attr_md;
getUnsecureCharacteristic(&char_md, &attr_char_value, 1, 1, 1, CUSTOM_VALUE_CHAR_UUID);
err_code = sd_ble_gatts_characteristic_add(p_cus->service_handle, &char_md,
&attr_char_value,
&p_cus->custom_value_handles);
if (err_code != NRF_SUCCESS)
{
return err_code;
}
return NRF_SUCCESS;
}
Unfortunately the sd_ble_gatts_characteristic_add functions returns a NRF_ERROR_NOT_SUPPORTED.
If I don't use the external function, the code works properly. This probably means I am doing something wrong with the memory allocation or setting the memory for those structures.
Does something looks suspicious? Thank you!
