When smartphone range is shorter than a peripheral(nRF5X), is there any way to receive an advertisement from the peripheral?

RE: When smartphone range is shorter than a peripheral(nRF5X), is there any way to receive an advertisement from the peripheral?

benevbright — Wed, 18 Oct 2017 20:29:01 GMT

@Sigurd, Thanks for your kind help. I will try that, and I believe my antenna is already tuned. And can you look my new question? Thanks. devzone.nordicsemi.com/.../

RE: When smartphone range is shorter than a peripheral(nRF5X), is there any way to receive an advertisement from the peripheral?

Sigurd — Tue, 17 Oct 2017 14:19:10 GMT

So back to my original question, in the position that smartphone and device can't be connected because of out of range but device's signal is enough to reach to the smartphone, Is there any way to send a data to the smartphone?

You can then try to send packets to the smartphone using regular advertisement packets. In this scenario I would recommend increasing the TX power on the nRF52 using the function sd_ble_gap_tx_power_set(). Default value is 0 dBm, but you can increase it to +9 dBm on the nRF52840.

For maximum range, tuning of the antenna is very important. Note that we at Nordic can tune the antenna on your product for free.

RE: When smartphone range is shorter than a peripheral(nRF5X), is there any way to receive an advertisement from the peripheral?

benevbright — Mon, 16 Oct 2017 14:58:33 GMT

Thank for your help. I will try it!

RE: When smartphone range is shorter than a peripheral(nRF5X), is there any way to receive an advertisement from the peripheral?

ta2 — Mon, 16 Oct 2017 14:55:58 GMT

Correct. If you don't need a response from the smartphone, then all you need is an output signal from your device that is strong enough to reach the smartphone. It doesn't matter whether or not the smartphone has enough power output to send something to your device.

In fact, that's why I suggested BLE_GAP_ADV_TYPE_ADV_NONCONN_IND. (Do I have that symbol typed in correctly? It looks odd.)

Anyway, NONCONN is advising any device that receives the advertising packet that there is no point in sending anything to your device. In NONCONN the receiver in your device is probably turned off to save power.

RE: When smartphone range is shorter than a peripheral(nRF5X), is there any way to receive an advertisement from the peripheral?

benevbright — Mon, 16 Oct 2017 14:42:20 GMT

@ta2, Ah yes, I understood. Then, in the position that smartphone and device can't be connected because of out of range but device's signal is enough to reach to the smartphone, Is there any way to send a data to the smartphone? (The smartphone doesn't have to respond to the device)

RE: When smartphone range is shorter than a peripheral(nRF5X), is there any way to receive an advertisement from the peripheral?

benevbright — Mon, 16 Oct 2017 14:40:07 GMT

hi @ta2, my answer is "no" and the smartphone doesn't have to send a response to my device. My question is for the situation when it can't make a connection because out of range. If they are in the range and it can be connected, everything is fine but I'm looking for the solution for that specific scenario. So back to my original question, in the position that smartphone and device can't be connected because of out of range but device's signal is enough to reach to the smartphone, Is there any way to send a data to the smartphone?

RE: When smartphone range is shorter than a peripheral(nRF5X), is there any way to receive an advertisement from the peripheral?

ta2 — Mon, 16 Oct 2017 14:39:14 GMT

Advertising and scanning are separate but related functions.

The Periperal device advertises based on some policy that you decide for the Peripheral's implementation. There are no commands that the smartphone can send to the Peripheral to cause it to start advertising. (Unless something changed in BT5.)

When you tell the smartphone to start scanning what you are really asking is for the smartphone to listen for advertisements. You are simply telling the radio (Bluetooth Controller) to passively listen for advertising packets. The smartphone will not send out any packets that cause Peripherals to start advertising.

The smartphone may make some transmissions during this period, but they will be in response to an advertising packet.

Is that clearer?

RE: When smartphone range is shorter than a peripheral(nRF5X), is there any way to receive an advertisement from the peripheral?

ta2 — Mon, 16 Oct 2017 14:20:50 GMT

Does your device need to know that the smartphone received the data?

If your answer is "no", then I think my response below is correct.

If your answer is "yes" - your device needs to know that the data was received by the smartphone, then the warning in the second paragraph of my response applies, and Sigurd's comments could be a solution to "paragraph two".

To continue on this line of thinking, the smartphone would need to send some kind of response to your device. That means you'll either need a connection, or use a Scan Request/Response mechanism to pass acks back and forth.

If you need the ack from the smartphone then the latter (Scan/Response) could be easier than making a connection.

Rather than clutter up this comment, if you do need the ack from the smartphone, I can outline my Scan Request/Response method at your request/convenience.

RE: When smartphone range is shorter than a peripheral(nRF5X), is there any way to receive an advertisement from the peripheral?

benevbright — Mon, 16 Oct 2017 14:04:30 GMT

Hi, I tested the advertising but it seems like that the smartphone get advertising data when it requests 'scanning' itself first. Then, If that 'scanning' signal does not reach to the peripheral, the peripheral does not send an advertising data? I'm confused.

RE: When smartphone range is shorter than a peripheral(nRF5X), is there any way to receive an advertisement from the peripheral?

benevbright — Mon, 16 Oct 2017 13:59:02 GMT

Hi Sigurd, I know that. I don't think you understood my question correctly or my description was bad. The situation I said above is that they can't communicate because it's out of range. It does not relative with BLE 5 Long Range but I only want to know if the smartphone that has shorter connection range than peripheral can receive the data from the peripheral when it's out of range to make a connection. (with using advertising or something) @Sigurd

RE: When smartphone range is shorter than a peripheral(nRF5X), is there any way to receive an advertisement from the peripheral?

Sigurd — Mon, 16 Oct 2017 13:13:27 GMT

Hi,

In this situation that they can't communicate each other, the connection between them will be disconnected.

If the phone does not support BLE 5 Long Range(CODED PHY/125kbps), you can still establish the connection between the phone and the nRF52840 using the normal PHY(1Mbps) defined in BLE 4.2. With the SoftDevice you can selected your preferred PHY, and you will get an event on the nRF52840 if the phone supported BLE Long Range(CODED PHY) or not.

RE: When smartphone range is shorter than a peripheral(nRF5X), is there any way to receive an advertisement from the peripheral?

ta2 — Mon, 16 Oct 2017 10:05:30 GMT

I think you should be fine. Advertising packets are unicast and do not require an acknowledgment.

You might have issues if you need to connect the devices or if you have additional information in a Scan Response. For both of these scenarios the device receiving the advertisement must respond with a Connection or Scan Request. If the device receiving the advertisement doesn't put out a signal strong enough to reach the advertiser, then a Connection or Scan Request will fail.

But again, as long as you are sending out information that you hope someone will hear, a non-connectable advertising packet (BLE_GAP_ADV_TYPE_ADV_NONCONN_IND) should be fine.

Also be sure to setup the Flags element in your advertising packet correctly. I think you will want the value 0x02 - indicating LE general discoverability only, but I haven't done one for awhile. (I'm sure someone will correct me if I have it wrong: -) )