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WiLink 8 Limitations

Kenny Koller
Prodigy 120 points
Other Parts Discussed in Thread: WL1837MOD

Hi,

I am in the process of evaluating components for a product that requires WiFi, GNSS, Bluetooth, and Bluetooth Smart.

The WL1837MOD looks promising. It does not give us GNSS but may satisfy the remaining needs.

If Class 1 power is required (100 mW) for a Bluetooth Classic connection is this strictly a hardware issue or must the stack support it in some way? What will be required to use the module and achieve Class 1 performance?

What are the limitations on the number of connections? Our requirements may be such that we must produce BT Smart notifications, while maintaining a varying number of Class 1 and Class 2 connections.

Perhaps some or all of this happens at higher levels in the stack and the question is reduced to can you simultaneously use Wifi, BT Smart, Class 1 BT, and Class 3 BT?

Many thanks,

Kenny

  • 0
    TI__Mastermind 32615 points

    Hi,

    WL18xx is "power class 1" device. the testing is done at 12dbm, please see the datasheet.  the power class is related to the hardware, The Power tables are loaded from the ROM. it can be changed from Service pack.

    Number of connections supported can be found in the data sheets (For BT 7, for BLE 10 BLE connections). But you can not have both Class 1 and Class 2 settings running simultaneously on the same DUT. But you can connect to Class 1 and Class 2 remote devices simultaneously.

    You can run WiFi, BT and BLE at a the same time. But not with different BT Class's 

  • 0 in reply to Sundeep Javvaji
    Prodigy 120 points

    Thank you Sundeep.

    Did you mean 20 dBm? I thought Class 1 was 100 mW.

    Can you change the power class (reload the power tables) dynamically or does it boot in one class or the other?

    Either way it sounds to me that if I want the long reach performance and connect simultaneously to Class 1 and Class 2 devices I must configure to Class 1. Are there any proximity effects in this case to consider? In practice can there be issues with a device being too close to a 100mW transmitter?

  • 0 in reply to Kenny Koller
    TI__Mastermind 32615 points

    Hi,

    With 20dBm you can get 100mW, which is the Maximum Output Power (Pmax). The Minimum Output Power can be   1 mW (0 dBm). Please see the section "TRANSMITTER CHARACTERISTICS" in the Bluetooth specification.

    I ma not sure why do you ant to change the Class of the device? Either your device is class 1 or class 2, It should be able to connect to all the bluetooth device (Either  class 1 or class 2) in the market. If it s in the range.

    It is possible to change the power table dynamically, after changing the power table you need to run calibration. see http://e2e.ti.com/support/wireless_connectivity/f/307/p/365576/1285269.aspx

    But I don't think you can change the class of device as you get certified for a specific class.

    like WL1835MOD is "power class 1" qualified (QDID: https://www.bluetooth.org/tpg/QLI_viewQDL.cfm?qid=22475)

  • 0 in reply to Sundeep Javvaji
    Prodigy 120 points

    Thanks again Sundeep.

    My understanding of radio and Bluetooth is limited. My concern might be battery life. It's not clear to me how you adjust power to the antenna. Our use-case is one device that may be tens of meters away and one that is 0.5 meters away. The long range mode is not always required. It'd be nice to adjust the output power. 

    The module was tested at 12.7 dBm per the datasheet. Is it capable of 100 mW? Perhaps we won't need this much power--testing and requirements will tell--but it'd be nice to know we can get to it.

  • 0 in reply to Kenny Koller
    TI__Mastermind 32615 points

    Hi,

    Please see the below table

    As a rule of thumb every 6 dB is around half the distance.

    The maximum WL18xx transmit is 15.5 dBm for GFSK on the chip (~50m) , after the module filter it’s 12.5 dBm.