Hi,
I am able to add custom services and characteristics dynamically. But still every time I need to refresh the nrfconnect application to see the newly added characteristics. Can I automate it, can I send any notification that new characteristics has been added from peripheral side, so that app can refresh it automatically. I want to know about peripheral side rather than client(mobile) side. Can anyone help me in this?
Hello,
To do this you will need to use the Services Changed notification - this lets your peripheral tell the central that there has been a change to the services / characteristics, and thus prompts the central to do a new discovery.
Please give this a try, and dont hesitate to let me know if you should encounter any issues or questions! :)
Best regards,
Karl
Hi, I called this function :
void our_service_change(ble_os_t * p_our_service)
{
uint32_t err_code_2;
static uint16_t start_handle= 0x000B;
const uint16_t end_handle = 0xFFFF;
err_code_2 = sd_ble_gatts_service_changed(p_our_service->conn_handle,
start_handle,
end_handle);
APP_ERROR_CHECK(err_code_2);
}
but its showing 12291 error, 12291 = 0x3003 and it's equal to BLE_ERROR_INVALID_ATTR_HANDLE.
I am using following code to add characteristics:
static uint32_t our_char_add(ble_os_t * p_our_service)
{
uint32_t err_code;
ble_uuid_t char_uuid;
ble_uuid128_t base_uuid = BLE_UUID_OUR_BASE_UUID;
char_uuid.uuid = BLE_UUID_OUR_CHARACTERISTC_UUID;
err_code = sd_ble_uuid_vs_add(&base_uuid, &char_uuid.type);
APP_ERROR_CHECK(err_code);
ble_gatts_char_md_t char_md;
memset(&char_md, 0, sizeof(char_md));
char_md.char_props.read = 1;
char_md.char_props.write = 1;
ble_gatts_attr_md_t cccd_md;
memset(&cccd_md, 0, sizeof(cccd_md));
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.read_perm);
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.write_perm);
cccd_md.vloc = BLE_GATTS_VLOC_STACK;
char_md.p_cccd_md = &cccd_md;
char_md.char_props.notify = 1;
ble_gatts_attr_md_t attr_md;
memset(&attr_md, 0, sizeof(attr_md));
attr_md.vloc = BLE_GATTS_VLOC_STACK;
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.read_perm);
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.write_perm);
ble_gatts_attr_t attr_char_value;
memset(&attr_char_value, 0, sizeof(attr_char_value));
attr_char_value.p_uuid = &char_uuid;
attr_char_value.p_attr_md = &attr_md;
attr_char_value.max_len = 4;
attr_char_value.init_len = 4;
uint8_t value[4] = {0x12,0x34,0x56,0x78};
attr_char_value.p_value = value;
err_code = sd_ble_gatts_characteristic_add(p_our_service->service_handle,
&char_md,
&attr_char_value,
&p_our_service->char_handles);
APP_ERROR_CHECK(err_code);
return NRF_SUCCESS;
}
Hello,
Please elaborate - were you successful in prompting a rediscovery, or did you encounter any issues or questions?
Please also use the Insert -> Code option when sharing code here on DevZone.
Best regards,
Karl
Hi, I am putting question properly with code again. No I was not able to
I called this function :
void our_service_change(ble_os_t * p_our_service)
{
uint32_t err_code_2;
static uint16_t start_handle= 0x000B;
const uint16_t end_handle = 0xFFFF;
err_code_2 = sd_ble_gatts_service_changed(p_our_service->conn_handle,
start_handle,
end_handle);
APP_ERROR_CHECK(err_code_2);
}
but its showing 12291 error, 12291 = 0x3003 and it's equal to BLE_ERROR_INVALID_ATTR_HANDLE.
I am using following code to add characteristics:
static uint32_t our_char_add(ble_os_t * p_our_service)
{
uint32_t err_code;
ble_uuid_t char_uuid;
ble_uuid128_t base_uuid = BLE_UUID_OUR_BASE_UUID;
char_uuid.uuid = BLE_UUID_OUR_CHARACTERISTC_UUID;
err_code = sd_ble_uuid_vs_add(&base_uuid, &char_uuid.type);
APP_ERROR_CHECK(err_code);
ble_gatts_char_md_t char_md;
memset(&char_md, 0, sizeof(char_md));
char_md.char_props.read = 1;
char_md.char_props.write = 1;
ble_gatts_attr_md_t cccd_md;
memset(&cccd_md, 0, sizeof(cccd_md));
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.read_perm);
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.write_perm);
cccd_md.vloc = BLE_GATTS_VLOC_STACK;
char_md.p_cccd_md = &cccd_md;
char_md.char_props.notify = 1;
ble_gatts_attr_md_t attr_md;
memset(&attr_md, 0, sizeof(attr_md));
attr_md.vloc = BLE_GATTS_VLOC_STACK;
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.read_perm);
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.write_perm);
ble_gatts_attr_t attr_char_value;
memset(&attr_char_value, 0, sizeof(attr_char_value));
attr_char_value.p_uuid = &char_uuid;
attr_char_value.p_attr_md = &attr_md;
attr_char_value.max_len = 4;
attr_char_value.init_len = 4;
uint8_t value[4] = {0x12,0x34,0x56,0x78};
attr_char_value.p_value = value;
err_code = sd_ble_gatts_characteristic_add(p_our_service->service_handle,
&char_md,
&attr_char_value,
&p_our_service->char_handles);
APP_ERROR_CHECK(err_code);
return NRF_SUCCESS;
}
I think setting end_handle to 0xFFFF is the issue. I doubt your attribute table has 65k entries. The API docs for sd_ble_gatts_service_changed states the context for BLE_ERROR_INVALID_ATTR_HANDLE:
"Invalid attribute handle(s) supplied, handles must be in the range populated by the application".
-Edit: Also, I think start_handle might need to be larger than zero, because that handle index is reserved.
