5 Replies Latest reply on Feb 27, 2020 2:16 AM by AnjanaM_61

    Can't set power on CYBT-483039-02

    DaHo_397236

      Hello,

      I'm trying to set Tx power on board CYBT_483039_EVAL for Advertisement with this code:

       

      wiced_bt_start_advertisements(BTM_BLE_ADVERT_OFF, 0, NULL);

      r = wiced_bt_ble_set_adv_tx_power(8);

      wiced_bt_start_advertisements(BTM_BLE_ADVERT_NONCONN_HIGH, BLE_ADDR_RANDOM, NULL);

       

      and result is 0 - OK. But when I'm reading curent value, the result is still 4.

       

      wiced_bt_ble_read_adv_tx_power((wiced_bt_dev_cmpl_cback_t *)read_tx_power_cb);

       

      void read_tx_power_cb(wiced_bt_tx_power_result_t *p_tx_power)

      {

          if ( (p_tx_power->status==WICED_BT_SUCCESS) && (p_tx_power->hci_status==HCI_SUCCESS) )

              WICED_BT_TRACE("adv tx power: %i\n", p_tx_power->tx_power);

      }

       

      Don't you have any idea what I'm doing wrong?

       

      And second question: What are the valid values of Tx power for this module? I'm little bit confused, somebody says the maximum power is +4dBm + gain of PA/LNA, others the max value is +16.

       

      Thanks,

      David

        • 1. Re: Can't set power on CYBT-483039-02
          AnjanaM_61

          Hi David,

           

          Please have a look at the following thread which clarifies your queries:

          CYBT-483039-02 documented PA/LNA control interface

           

          Thanks,

          Anjana

          • 2. Re: Can't set power on CYBT-483039-02
            DaHo_397236

            Hello Anjana,

            thank you for quick response.

            So I see that valid Tx power levels for this chip are [4, 0, -4, -8, -12, -16, -20, -24] dBm, and I have probably module set up to maximum Tx power. In real test in open air I find out usable range about 140-180m against mobil phone held by hand. Could it be adequate?

             

            Are there any limitations how and when to set Adv Tx power? I tried call wiced_bt_ble_set_adv_tx_power(-8) when beacon advertising is on and off, but verification by wiced_bt_ble_read_adv_tx_power(cb) always returns 4. I have no idea where the problem might be.

             

            Thans for patience,

            David

            • 3. Re: Can't set power on CYBT-483039-02
              AnjanaM_61

              Hi David,

               

              I was able to reproduce the issue with CYW20719 . The issue is only with WICED 6.2, its fixed in WICED 6.4

              But unfortunately CYW20719 based Ez- serial modules have some known issue of inconsistent behavior in WICED 6.4. This will be fixed in next WICED SDK 6.5 version.

              If 4dBm tx power (max power setting) is fine for your application, you can carry on development with WICED 6.2 for now and can shift to WICED 6.5 later.

              Sorry for the inconvenience caused.

               

              Thanks,
              Anjana

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              • 4. Re: Can't set power on CYBT-483039-02
                DaHo_397236

                Hi Anjana,

                thanks for verification of my problem. I started with WICED 6.4, but than I found the issue with CYW20719 and I downgraded IDE to 6.2.

                 

                What do you think about the real usable range of nonconnectable beacon advertising of this modul with max Tx power? I tryied test with mobile phone in open air and I see the beacon in range up to 180m. I expected a little bit more.

                 

                When are you planig to release WICED 6.5? Now I can't change Tx power and I'm afraid that the value of 4dBm with PA is too much for Europe regulations.

                 

                Thanks,

                David

                • 5. Re: Can't set power on CYBT-483039-02
                  AnjanaM_61

                  Hi David,

                   

                  Range will depend on so many parameters like the line of sight , environment , module placement etc. We don't have practically tested values for max range.

                  I am sorry , I am not sure about WICED 6.5 release as it is still under process. I understand your point on regulatory certification.

                  I would suggest you to contact any of our local sales support for help on WICED release.

                   

                  Thanks,
                  Anjana

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