CC2640R2F: No difference in range between 1M PHY and Coded PHY advertisements

Emil George

Part Number: CC2640R2F

Hi,

I'm using CC2640R2F for communication between two boards: a sensor board (peripheral) and main board (central). A broadcaster-observer scheme is followed for communication (data is sent via advertisements, no scanning/connection).

I tested the range in these two modes: 1M PHY only, and Coded PHY (S8) only. But I am getting almost same range for both (8-10 m). Both at 5 dBm TX power.

In the peripheral: I'm using

GAPADV_PARAMS_LEGACY_SCANN_CONN

for 1M PHY and,

GAPADV_PARAMS_AE_LONG_RANGE_CONN

modified for CODED PHY (S8).

In the central:

For 1M:

GapScan_setParam(SCAN_PARAM_PRIM_PHYS, &temp8); // temp8 = SCAN_PRIM_PHY_1M

For Coded:

GapScan_setParam(SCAN_PARAM_PRIM_PHYS, &temp8); // temp8 = SCAN_PRIM_PHY_CODED

I verified that the mode is actually being switched by using a BLE scanner android app that shows the type of advertisements (Legacy vs LE Coded).

Shouldn't the S8 Coded PHY have 4 times (or atleast close) the range than 1M PHY? Is there anything I can do to improve the range?

over 6 years ago

0 J Lindh over 6 years ago

TI__Guru 57865 points

Hi Emil,

You should see an increased range. What SDK version are you using and do you run on a TI launchpad?

0 Emil George over 6 years ago in reply to J Lindh

Prodigy 40 points

Hi Joakim,

I'm using simplelink_cc2640r2_sdk_2_30_00_28, and it's running on a custom board based on CC2640R2F.

0 YiKai Chen over 6 years ago in reply to Emil George

Guru 735695 points

simplelink_cc2640r2_sdk_2_30_00_28 is obsolete. I would suggest you to try latest simplelink_cc2640r2_sdk_3_20_00_21.

0 Emil George over 6 years ago in reply to YiKai Chen

Prodigy 40 points

Hi YK Chen,

I'll try after updating to the latest version, and get back to you soon.

Thank you.

0 J Lindh over 6 years ago in reply to Emil George

TI__Guru 57865 points

Please also make sure you are following these guidelines with the board design:

http://www.ti.com/lit/pdf/swra640

0 Emil George over 6 years ago in reply to J Lindh

Prodigy 40 points

Hi Joakim,

We went through the document and could not find any issues with the design. Updating the SDK did not help either.

- Emil

0 J Lindh over 6 years ago in reply to Emil George

TI__Guru 57865 points

Hi Emil,

When you run the code on TI launchpads, do you see a clear difference in range? I'd like us to figure out if this is SW or HW related.

0 Robert Kinicki over 6 years ago in reply to J Lindh

Prodigy 110 points

Hello all,

I would like to report that I am seeing the same behavior between two CC2640R2F Launchpads. I have one running simple_central and the other running simple_peripheral. I see no difference in range between 1M and Coded PHY settings. In fact the Coded PHY range is slightly WORSE?!? I am very interested in the resolution to this issue as well.

Thank you,

Bob

0 Elin W over 6 years ago in reply to Robert Kinicki

TI__Genius 14845 points

Hi Bob,

1) Did you test both S=2 and S=8?

2) Can you measure the RSSI with SmartRF Studio to check the noise floor of your launchpads?

I just did a test with a connection between simple peripheral og simple central in a connection and around 100 m the connection is still fine...

0 Robert Kinicki over 6 years ago in reply to Elin W

Prodigy 110 points

Hi Elin,

1) I tested with S=8 only

2) I have never used SmartRF studio, but I can give it a try if I get a chance.

I too was able to see around 300ft (a little under 100m) outdoors, line-of-sight, but...

a) I saw the same 300ft regardless of using coded PHY or not

b) Outdoors, line-of-sight is not a realistic test. We were wanting indoor whole house coverage (through walls, floors, etc...).

It seems to me that for BLE we would be better off using a higher power transmitter that will actually get us more range and transmit

faster so that the average power is roughly the same.

I am thinking BLE will not work for us and I should start exploring sub-GHz Zigbee or Z-Wave?

0 Elin W over 6 years ago in reply to Robert Kinicki

TI__Genius 14845 points

Hi Bob,

Have you tried with SmartRF Studio? Did you get the same result?

Are you using the examples as is or have you made any modifications?

It should be possible to get a good range using BLE, the test I performed last week was indoors in a busy area.

Thanks,
Elin

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CC2640R2F: No difference in range between 1M PHY and Coded PHY advertisements