• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 52 subscribers
  • Views 903 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

How to increase Tx power during audio data transmission?

Christina Lim
Expert 6345 points
Other Parts Discussed in Thread: CC2541, CC2540, CC2590

Hi, 

There are feedbacks from customer that the distance of their BLE Voice Remote (using CC2541) for a good audio transmission is too short ; about 5 – 6m in normal environment (= less noise), and 1 – 2 m in noisy environment ; which is too short.

While we worked to increase the transmission power, can you help advise on the following questions?

1)      Is the audio library limit the TxPower when transmitting audio data ?   if yes, at what value ?

2)      How to increase the TxPower during audio data transmission ?

  • Is it by using ‘llStatus_t LL_EXT_SetMaxDtmTxPower( uint8 txPower )’ ?
  • Or, using ‘HCI_EXT_SetTxPowerCmd( uint8 txPower )’ (as per suggestion in TI Wiki – BLE – FAQ) ?
  • Or, any other method ?

3)      What’s the maximum TxPower for CC2541 BLE ?   is it 4.5dB max ?

Thanks!

Christina 

 

  • 0
    TI__Guru** 106705 points
    Hi Christina,

    The SW does not limit TX power at any time, it runs at the set value which by the default is 0 dBm. In other words: 1) No; 2) NA; 3) 0 dBm.

    With the range you outline it sounds like something is wrong with their HW. Most likely it is a problem with the RF layout and/or the antenna matching. Do you know if they have done any RF measurements to check the performance of their design?

    Cheers,
    Fredrik
  • 0 in reply to Fredrik K
    TI__Expert 6345 points

    Hi Fredrick,

    If we are referring to CC2540, would the following works to alter the TxPower using code?

    Using ‘llStatus_t LL_EXT_SetMaxDtmTxPower( uint8 txPower );’or ‘HCI_EXT_SetTxPowerCmd( uint8 txPower );’ routines can only set to 4 different values: -23dBm,-6 dbm,0dbm, and 4dBm.

    ·         LL_EXT_TX_POWER_MINUS_23_DBM,

    ·         LL_EXT_TX_POWER_MINUS_6_DBM,

    ·         LL_EXT_TX_POWER_0_DBM,

    ·         LL_EXT_TX_POWER_4_DBM

    Note:    Looking at the options available for the variable ‘txPower’, it seems follows the TxPower options available for CC2540.

    Please refer to “Table 1. Output Power” in CC2540.

    The max TxPower for CC2540 is rated at 4dBm, can we use the above command to select it to 4dBm?

    Thanks,

    Christina

  • 0 in reply to Christina Lim
    TI__Guru** 106705 points
    Hi Christina,

    The maximum output power for CC2540 is 4 dBm, the maximum output power for CC2541 is 0 dBm.

    Anyway, I think you should focus on checking the RF performance of the remote.

    Cheers,
    Fredrik
  • 0 in reply to Fredrik K
    TI__Guru** 105180 points
    Hi Christina,

    Please use HCI_EXT_SetTxPowerCmd to adjust the output power. If higher power is required, you can use a CC2590.
    As Fredrik states, there is likely some other issue that the TX power is masking. I would also check for Wi-Fi interference and make sure the Channel Map Update is used to mask the channels with higher interference.

    Best wishes