CC2652P: Tx Power out / Range problem

Hi,

Thank you for reaching out.

First of, I would recommend you verify which LaunchPAd you are using:

LAUNCHXL-CC1352P1: 868/915 MHz up to 20 dBm, 2.4 GHz up to 5 dBm
LAUNCHXL-CC1352P-2*: 868/915 MHz up to 14 dBm, 2.4 GHz up to 20 dBm
LAUNCHXL-CC1352P-4*: 433 MHz up to 14 dBm, 2.4 GHz up to 10 dBm

Then, I would recommend to change the "Default TxPower" to 10 dBm. You can use a RF signal analyzer to verify the actual power outputted by the device.

Then, if possible, I would recommend to use an external antenna rather than the PCB antenna of the LaunchPad. The transmitted power through the PCB antenna is limited and the efficiency of the PCB antenna is lower than what can be achieved with an external antenna. Please review this piece of documentation to flip the capacitor in order to enable the use of the external antenna.
If you are interested, this is an external antenna I have used before.

Last but not least, if the Bluetooth 1M PHY does not suffice to meet your range requirements, you may want to consider using a LE Coded PHY.

I hope this will help,

Best regards,

Hello Clement,

1. We are using LAUNCHXL-CC1352P-4*: 433 MHz up to 14 dBm, 2.4 GHz up to 10 dBm Launchpad as receiver and CC2652P1 as transmitter.

2. Then, I would recommend to change the "Default TxPower" to 10 dBm. You can use a RF signal analyzer to verify the actual power outputted by the device.
We cannot see 10 DBM option in the Drop Down Menu as you can see in the Image below I can see -20 to +5 only. 

Also If you refer this thread https://e2e.ti.com/support/sensors-group/sensors/f/sensors-forum/613223/awr1243-how-to-calculate-the-precise-power-on-the-tx-and-rx-pin there is some point of backoff power. I hope this is not what we are talking about.



3. I have selected my Front end as Differential and designed the same. I have used a RF switch and used internal power amplifier for High power. So my Bias Configurations are set as Internal Bias as you can see in the first Image.

Now when I go to the RF Design section in Sysconfig I can see that Front end for 2.4 Ghz is set as External Biased ,Differential Bias. Refer Below Image - 

Are these settings correct ? Or do I need to do any changes.

I understand I need a RF analyzer to look into this but currently we want to do some bench validation before proceeding with RF analyzer.

NOTE: We are using External antenna only with the recommended Cap change. our Dipole antenna approx. matches your antenna configurations.

Can you please answer all above points.


Regards,
Ankit Tomar

Hi,

May I kindly ask which SDK version you are using?

It looks like we are not having the exact same version:

Could you please try to download the latest SDK (6_10) and see if the issue persists? Here is the link to download the SDK: https://www.ti.com/tool/download/SIMPLELINK-CC13XX-CC26XX-SDK

Best regards,

I am Using SKD simplelink_cc13x2_26x2_sdk_4_10_00_78, the project is fully developed. Changing SDK this time is not feasible.

Can you please let me know the answer of point 3.

Do you have any other suggestions. The power is so low that I cant able to get data inside the car 2m apart form slave.

Thank You 

Hi,

To answer point 3, I guess you should set the same configuration in all the places.

Ankit Tomar said:

The power is so low that I cant able to get data inside the car 2m apart form slave.

This definitely makes me think there is an issue either on the hardware side, either on the software side. Even if the devices transmit at 0dBm, you should achieve much longer range.

I would recommend to run some tests using the newer SDK with the newer configurations. That way you will manage to assess if an hardware issue may actually occurs as well. It will also help you to identify the proper configurations. Alternatively, you may want to use SmartRF Studio (https://www.ti.com/tool/SMARTRFTM-STUDIO).

To finish, I think your tests would be faster if you had a way to measure the strength of the signal outputted by the device. I mentioned the possibility to use an RF analyzer, but you could start by leveraging SmartRF Studio (especially if the environment is quiet).
With these tools you'll have the possibility to directly see the effects of the configuration changes applied and save time.

Best regards,

Hi,

I will check with the power with the RF analyzer and will come back to you.

As you can see in this Query asked - (+) AWR1642: TX output power setting in Config profile - Sensors forum - Sensors - TI E2E support forums and also this (+) AWR1642: output power and antennta gain - Sensors forum - Sensors - TI E2E support forums

They have mentioned that Tx power is a backoff power and not what we want??

Is this correct ? Does setting 10 Db to TX power actually reduces the power by 10 ?

What if I select -20 ? will this increase the power ? As I can see -20 to 5 range.

Does new SDK's changelog has anything which effect the range ?

Related to Hardware, I assume we don't need to do any changes in the PinConifg side, the same switch can be used to throw 10 DBM signals ?

Regards,
Ankit Tomar

Hi again,

Ankit Tomar said:

As you can see in this Query asked - (+) AWR1642: TX output power setting in Config profile - Sensors forum - Sensors - TI E2E support forums and also this (+) AWR1642: output power and antennta gain - Sensors forum - Sensors - TI E2E support forums

To be clear, the threads you are referring to are NOT for CC2652P. The threads you are referring are related to the AWR1642 which is a radar device (not a connectivity device).

Best regards,

Hey,

Sorry, maybe I misunderstood it.
Thanks for the Quick help.

I will get back to you once I have results with the RF Analyzer.

Regards,
Ankit Tomar

Hi,

I just tried checking with the default example code as simple central, with SDK sdk_4_10_00_78 and I saw that in example code itself the default power is set to 0 DBM also the max it could reach is 5 DBM and min -20 DBM.



Can I know is this SDK specific ?

Regards,
Ankit Tomar

Hi,

On SDK 4_10, the feature you need is not supported. This is why we recommend to migrate to a newer SDK.

Best regards,

Hi,

Does this mean 10 DBM or PA is not available / cannot be used while using this SDK. 

We conducted a test and saw a little improvement while  selecting 5 instead of 0.

Regards,
Ankit Tomar

Hi,

Ankit Tomar said:

Does this mean 10 DBM or PA is not available / cannot be used while using this SDK. 

Your understanding is correct.

The issue has been fixed in SDK 4.30. You can refer to the release notes of the SDK and more specifically to the issue BLE_AGAMA-2192 for more details.

Best regards,

Hi Clement,

I checked on RF analyzer the power of our sensors and found that with all the settings changes like changing my DB levels to 0,2,3,4,5 and in HP settings 6,7,8,9,10 I saw no change at all in power. The power I can see is -32dBm considering the path loss its I guess its +5 dBm (correct me if I am wrong Tx gain - 2 Rx gain 3, distance 1meter). Is this an issue which is also fixed or there is some problem with my testing methodology. As I saw same power across all db ranges.

Also can you please provide me Migration Guide to migrate from SDK 4_10_00_78 to latest SDK 6

Regards,
Ankit Tomar

Hi,

For the tests, I would recommend to verify if you can reproduce using https://www.ti.com/tool/SMARTRFTM-STUDIO

The migration guides are available here. Generally speaking, I would recommend you to leverage the year-to-year migration guides,  i.e. migrate from 4.10 to 5.10 then from 5.10 to 6.10.

I hope this will help,

Best regards,

Hello,

Thank you for the suggestions.

Meanwhile your Year-to-Year Migration Guides Migration page currently has only SDK 4.1 to 5.1 migration help.

I cannot see SDK 5.1 to 6 porting. Reference  - Porting Guide and Migration Guides — SimpleLink CC13XX/CC26XX SDK BLE5-Stack User's Guide 2.02.04.00 documentation

Thank you

Hi,

Ankit Tomar said:

Meanwhile your Year-to-Year Migration Guides Migration page currently has only SDK 4.1 to 5.1 migration help.

I cannot see SDK 5.1 to 6 porting. Reference  - Porting Guide and Migration Guides — SimpleLink CC13XX/CC26XX SDK BLE5-Stack User's Guide 2.02.04.00 documentation

The User's Guide you are referring to is for SDK 5.40 (hence the absence of the porting guide to 6.10).

Please make sure to follow the link in my previous message (or https://dev.ti.com/tirex/content/simplelink_cc13xx_cc26xx_sdk_6_10_00_29/docs/ble5stack/ble_user_guide/html/ble-stack-5.x-guide/migration-cc13xx_cc26xx.html#year-to-year-migration-guides)

Best regards,

Hello Clement,

I have few more doubts on the tests analysis that I did using RF Analyzer.

In the tests I conducted on RF Analyzer I found that the RF Power Increases on increasing the Distance. i.e. I saw on 3 meter distance the power seen is around 10 dBm. Under the Advertisement parameters I have set the Tx Power as TX Power and not Controller will choose TX Power. Still I see this. I want it to be 10 dBm by default.

If this is correct is the Default Tx Power is what we need to switch to 10 dBm which is available on sdk 4.3 and over.

As I am very new to this can you suggest mw which example code should I use as I am using CC2652P1, so should I use example code of CC1352P2 or P4 to migrate the files. I understand how to migrate the files. I tried using 1352P2 code as it supports 10 dBm but I cannot see 10 dBm option in the 5.1 sdk. I can see from 14 to 20 directly, but using 1352P4 I can see 10 dBm option. So which example code to use.

Regards,
Ankit

Hi Ankit,

To be honest, I am more a protocol and software expert than an RF expert. For the questions related to RF measurements, it would be best if you could open a new thread. That way, our RF experts will be able to help.

Thank you for your comprehension.

Best regards,

Hi Clement,

Thank you for the Help I have opened a new thread.

Regards,
Ankit

Hello Clement,
As you told that migrating to 4.30 is solution.

I would like to know that in the previous sdk are we transmitting the signals using 5 dBm path only even if high PA is used or are we transmitting less than 5 dBm using high PA path only or we are not sure via which path it is transmitting using old sdk.

I want to know the exact issue in old sdk considering we rae using switch for PA and 5dbm path.

I hope despite closure of this thread you will reply me back.

Regards,
Ankit

Hello Clement, 

Can you please answer to my query asked. As because of this Bug we may have to consider retuning of our boards.
Awaiting your response.

Regards,
Ankit