Hello, I'm sending a series of data up to 7 bytes from an android phone, but I can only receive the first 5.
I'm asking what are the list of thing to mind if I were trying to receive more?
I'm sending them over GATT, more specifically, gatts_evt.params.write.
At first nothing works out,the p_ble_evt.header.evt_id wasn't even correct (sorry I wasn't able to breakpoint and see the value) Now it is correct, 0x0050 (write)
It became correct after I gradually increased the size of my payload from 2 to 5, then to 7. It was at first not correct when it was 7, but then I reduced the payload to only 2, it worked properly, then to 5, again, worked well, now 7, which SHOULDN'T work, but worked anyway, that is, p_ble_evt.header.evt_id now has the proper value of 0x0050, which is extremely strange since it wasn't that value when the payload was 7 bytes at first, but somehow, it maintains the value 0x0050 after I changed the payload from 2bytes to 5bytes then to 7 bytes.
Now the problem is that although 7 bytes were all sent, I can only recieve the first 5, the remaining 7 could no where be found, probably discarded, although I am not sure which one discarded it, the phone or nrf51.
What did I do wrong? What are the things to mind when configuring a characteristic to solve this?
Update: actually I can only write 2 bytes now for some reason I used to write 7 and have the first 5 properly received, but now I can only do 2 after tampering with characteristic initialization, the actual init parameters are as follows:
/* BLE GATT metadata */
ble_gatts_char_md_t ble_char_md;
memset(&ble_char_md, 0, sizeof(ble_char_md));
ble_char_md.char_props.write_wo_resp = 1;
ble_char_md.char_props.notify = 1;
// ble_char_md.char_props.read = 1;
// ble_char_md.char_props.write =1;
// ble_char_md.char_props.indicate =1;
// ble_char_md.char_props.auth_signed_wr =1;
ble_char_md.p_cccd_md = NULL;//once commented, now enabled to restore the original config, 12-23
ble_char_md.p_sccd_md = NULL;
ble_char_md.p_char_user_desc = NULL;
ble_char_md.p_user_desc_md = NULL;
/* ATT metadata */
ble_gatts_attr_md_t ble_attr_md;
memset(&ble_attr_md, 0, sizeof(ble_attr_md));
/* No security is required */
ble_attr_md.write_perm.lv = 1;
ble_attr_md.write_perm.sm = 1;
// BLE_GAP_CONN_SEC_MODE_SET_OPEN(&ble_attr_md.read_perm);
// BLE_GAP_CONN_SEC_MODE_SET_OPEN(&ble_attr_md.write_perm);
// ble_char_md.p_cccd_md = &ble_attr_md;
// ble_char_md.char_props.notify = 1;
ble_attr_md.vloc = BLE_GATTS_VLOC_STACK;
ble_attr_md.rd_auth = 0;
ble_attr_md.wr_auth = 0;
ble_attr_md.vlen = 1;
/* ble characteristic UUID */
ble_uuid_t ble_uuid;
ble_uuid.type = m_mesh_base_uuid_type;
ble_uuid.uuid = MESH_VALUE_CHAR_UUID;
/* ble attribute */
ble_gatts_attr_t ble_attr;
uint8_t default_value = 0;
memset(&ble_attr, 0, sizeof(ble_attr));
ble_attr.init_len = 1;
ble_attr.init_offs = 0;
ble_attr.max_len = sizeof(mesh_gatt_evt_t);
ble_attr.p_attr_md = &ble_attr_md;
ble_attr.p_uuid = &ble_uuid;
ble_attr.p_value = &default_value;
/* add to service */
uint32_t error_code = sd_ble_gatts_characteristic_add(
m_mesh_service.service_handle,
&ble_char_md,
&ble_attr,
&m_mesh_service.ble_val_char_handles);
if (error_code != NRF_SUCCESS)
{
return NRF_ERROR_INTERNAL;
}
return NRF_SUCCESS;
