Author Topic: Simblee BLE stack wireless range terrible? Configuration problem?  (Read 427 times)

adme

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All,

We have a product that uses Simblee and we are using the SimbleeBLE stack.

It is a simple connection: (LED)<------{PCB with Simblee)<------>(LiPo Battery)

We are however having very unreliable Bluetooth connection.

The range is very very short, between 20 to 60 ft.

Additionally the devices disappear now and then from being discovered
or visible on the network. This is a very bad user experience.

The forum link below suggest that Simblee can have a range of 500ft LOS.
http://forum.rfduino.com/index.php?topic=1566.0
Is that possible?

Your article below implies that the range is adjustable
https://www.simblee.com/Simblee%20RFD77101%20Datasheet%20v1.0.pdf

1--- Is this correct?

2--- Can you list a few things we should be checking to make sure we have setup the firmware, chip, casing, etc, properly to ensure maximum range?
3--- What is a reasonable range to expect?
4--- What do we have to check to make sure the device does not randomly disappear from the network and not discoverable?

I have not heard back from RF Digital support email yet.

5--- Any faster way you to get attention?
6--- Anyone in this forum willing to consult on troubleshooting the bluetooth issues?

Looking forward to feedback from members or RFDigital.

tolson

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Re: Simblee BLE stack wireless range terrible? Configuration problem?
« Reply #1 on: August 03, 2017, 06:13:55 PM »
Hi adme,

All good questions. Hopeully someone in the know from RFDigital will give full details.

One thing that might be affecting your distance. Within the Simblee Chip itself they tied GPIO31 to a switch, which essentially attenuates the antenna so it is only good for up close. I assumed the closeness was on the order of a few inches like perhaps for doing something like NFC. But who knows. Perhaps 20 feet is it.

It is described in the SimbleeCOM documentation. Sometimes the INCLUDES and CPP files in the libraries provide interesting explanations.

From the SimbleeCOM pdf file...
SimbleeCOM.proximityMode
Proximity mode brings the range of the Simblee module to a very close proximity. This is for use in security
applications, or when connection to a Simblee device requires the user to be very close.

SimbleeCOM.proximityMode(FALSE); //proximity mode is set to FALSE on default

And from the INCLUDES/CPP files that API does this..
Code: [Select]
void SimbleeCOMClass::proximityMode(bool enable)
{
  if (enable)
    NRF_GPIO->OUTSET = (1 << 31);
  else
    NRF_GPIO->OUTCLR = (1 << 31);
}

The SimbleeBLE INCLUDE has a similar function...
Code: [Select]
void SimbleeBLEClass::proximityMode(bool enable)
{
  if (enable)
    NRF_GPIO->OUTSET = (1 << 31);
  else
    NRF_GPIO->OUTCLR = (1 << 31);
}


So I assume the API would be like..
SimbleeBLE.proximityMode(FALSE);

Give it a try!

Another thing to look at using is the txPowerLevel API. Odds are there are conflicts with that and the antenna attenuator. Need detailed engineering explanation of how this stuff is connected and used to know for sure.

SimbleeBLE.txPowerLevel = +4; // Sets transmit power to max +4dBm.
Possible values are -20, -16, -12, -8, -4, 0, +4
The default is suppose to be +4.

At any rate, your best path to trying to understand things is to take a look at the comments within the various INCLUDE files.

And then there is...
Not knowing how you laid out your PCB, you can't have any metal or traces crossing under the antenna area of the chip. This could be your problem. If you look at the old RFduino chip documentation, they published excellent RF layout considerations. The same rules apply for the much smaller Simblee module(chip).
« Last Edit: August 07, 2017, 07:32:19 AM by RFD_Nelson »

adme

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Re: Simblee BLE stack wireless range terrible? Configuration problem?
« Reply #2 on: August 03, 2017, 10:25:06 PM »
Hi tolson,

Thanks for your detailed response.
We will double check all the suggested INCLUDE(s) setups and the layout and report back.



adme

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Re: Simblee BLE stack wireless range terrible? Configuration problem?
« Reply #3 on: August 07, 2017, 11:25:00 AM »
For some reason, we can find "SimbleeBLE.txPowerLevel" in the libraries.
But we cannot find
SimbleeBLE.proximityMode(FALSE);
So, that is curious.

We are in contact with RFDigital, as in they want more info.
Will update as soon as we have new info.


tolson

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Re: Simblee BLE stack wireless range terrible? Configuration problem?
« Reply #4 on: August 07, 2017, 12:27:08 PM »
Knowing that it is just turning GPIO 31 on and off you can just use the Arduino way of doing that.

pinMode(31, OUTPUT);

digitalWrite(31, HIGH);
or
digitalWrite(31, LOW);

 

anything