Issue in DA14531 MOD Bluetooth range

Hi Laxmi,

Thank you for posting your question online.

laxmi said:

But the same code is flashed to other Module, which is not working beyond 5 meters.

How do we say it is hardware of DA14531 MOD issue or Firmware issue?

It would be difficult to be hardware problem of the DA14531MOD. Only if the installation on your custom PCB has not been made as stated in the Guidelines there could be issues with the RF performance.
Please refer on DA14531MOD Datasheet, section 8 Design Guidelines, page:17

laxmi said:

How can we check the power level is really set to +2.5dBm?

Please refer here: 9. AT Commands — DA145XX Tutorial SDK Getting started (renesas.com)
You can use the AT+PWRLVL command to get the power level.

Best Regards,
OV_Renesas

Hi,

OV_Renesas said:

It would be difficult to be hardware problem of the DA14531MOD. Only if the installation on your custom PCB has not been made as stated in the Guidelines there could be issues with the RF performance.
Please refer on DA14531MOD Datasheet, section 8 Design Guidelines, page:17

As per Design Guidelines, we have designed and placed DA14531 MOD in our custom board. But still we are facing BT range issue with some modules. 

OV_Renesas said:

Please refer here: 9. AT Commands — DA145XX Tutorial SDK Getting started (renesas.com)
You can use the AT+PWRLVL command to get the power level.

Through AT command we have already tested and it showing expected value.

Regards,

Laxmi Narayana.

Hi Laxmi,

Thank you for the reply.

laxmi said:

As per Design Guidelines, we have designed and placed DA14531 MOD in our custom board. But still we are facing BT range issue with some modules. 

Did you follow the same procedure for all the custom boards? How many boards have this issue?
Did you make sure to follow the Soldering Guidelines as well on section 9 Soldering page 22?
Would it be possible to remove the DA14531MOD from the custom board and test it separately to see if it has the correct behavior?

Best Regards,
OV_Renesas

Hi OV,

OV_Renesas said:

Did you follow the same procedure for all the custom boards?

Yes we have followed the same procedure for all custom boards.

OV_Renesas said:

How many boards have this issue?

Out of 10 modules we noticed the issue in 3 modules.

OV_Renesas said:

Did you make sure to follow the Soldering Guidelines as well on section 9 Soldering page 22?

Yes, we followed the same Soldering Guidelines.

OV_Renesas said:

Would it be possible to remove the DA14531MOD from the custom board and test it separately to see if it has the correct behavior?

Yes, as you suggested we have removed DA14531MOD from custom board and verified the same. but still BT module disconnecting for 5 meter range.

Please let us know how can it be fixed.

Regards,

Laxmi Narayana.

Hi OV_Renesas,

Please let me know if you found any solution for this issue.

Regards,

Laxmi Narayana.

Hi Laxmi,

Thank you for the reply and clarifications.
I believe there was an issue during Soldering/desoldering on the custom boards.
Could you please probe the XTAL pins during boot time so we can check the Oscillator behavior?

Best Regards,
OV_Renesas

Hi OV_Renesas,

Thank you for reply,

OV_Renesas said:

Could you please probe the XTAL pins during boot time so we can check the Oscillator behavior?

As i mentioned we are using DA14531 MOD and the XTAL will be under shield. How to probe the XTAL ?

Regards,

Laxmi Narayana.

Hi Laxmi,

Thank you for the reply.

laxmi said:

As i mentioned we are using DA14531 MOD and the XTAL will be under shield. How to probe the XTAL ?

You are correct, the XTAL pins are not exposed. It would require you remove the shield of the module.
Before doing that, please try the following change on the Codeless SDK AT+PWRLVL command.
After several trials, we found that the AT+PWRLVL command, is not correctly initializing the radio after the level change. We replaced the following line in user_at_commands.c file in function user_at_pwrlvl and now it is has the expected Power level at all times:

            rf_pa_pwr_set((rf_tx_pwr_lvl_t)result);
            //set_recommended_settings();                           
            rf_reinit();                                          

Hi OV_Renesas,

Thank you for quick reply, we will definitely try your suggestion.

DA14531 MOD supports Max power level of +2.5 dBm which we are setting up in our all BT modules to meet our requirement of BT range (25 to 30)meters.

My doubt is if we set max power level for BT module, will be any issues in Power Amplifier performance?

is it suggestable to use Max power level?

Regards,

Laxmi Narayana. 

Hi Laxmi,

Thank you for the reply.

laxmi said:

DA14531 MOD supports Max power level of +2.5 dBm which we are setting up in our all BT modules to meet our requirement of BT range (25 to 30)meters.

My doubt is if we set max power level for BT module, will be any issues in Power Amplifier performance?

Yes, increasing the Tx Power output will affect the current consumption.
Please refer here: 4. User Guides — DA14585/DA14531 SW Platform Reference Manual (renesas.com)

laxmi said:

is it suggestable to use Max power level?

It will not affect the performance of the DA14531MOD but it will affect the current consumption.

Best Regards,
OV_Renesas