Custom built cc2541 BLE peripheral device cannot be found by Smartphone but can be found by CC2540 USB Dongle

I built a cc2541 peripheral device (the schematic is attached) running original SimpleBLEPeripheral example code. The device can be detected by either BTool or BLE device monitor through  CC2540 USB Dongle on a laptop, and the signal is very good. The RSSI reading can be -40. However, it was not shown on smartphones, iPhone 5 using BLE Utility app or Samsung Galaxy S3 using Bluetooth LE Scanner app. Does anyone know any hardware or software reasons for this? Thank a lot in advance!

7 Replies

  • I don't remember exactly the reason for such behavior, however this is not the right forum for such question.

    Post your question in Bluetooth® Low Energy Forum

    Good luck

    Br,
    Igor.

    Thank you for marking the thread as answered if your question was answered :)

  • In reply to Igor Sherer:

    Thank you for your advice! I reposted it in BLE forum. Could you also point me some possible directions for the potential problem? Thanks again!
  • In reply to Quan Dong:

    I really don't remember, as I stumbled with this issue several years ago, however, I do recall it was something easy to fix.
    I bet that in couple of hours someone from the BLE forum will guide you through this issue

    Br,
    Igor.

    Thank you for marking the thread as answered if your question was answered :)

  • In reply to Igor Sherer:

    Thanks! People from BLE forum suggest me do a RF-PHY test on antenna. Beside antenna, I suspect the 32 MHz crystal. I removed load caps to save space. Does it ring a bell?

    Br
  • In reply to Quan Dong:

    I'm aware of your chat in BLE forum (I'm tracking almost all the posts in Wireless forums) :)
    Removing the caps might pose some problem, but first do the RF-PHY test and come with results

    Br,
    Igor.

    Thank you for marking the thread as answered if your question was answered :)

  • In reply to Igor Sherer:

    Hi Igor,

    I'm build a device for research in university rather than a commercial product. Sending the device out for RF-PHY test is costly for me. Is there any alternative test or any test I can do in the lab?

    Best regards,
    Quan
  • In reply to Quan Dong:

    You could program the sniffer device, which assume is also a TI's dongle, with the same software as you programmed your custom device.
    If it doesn't connect either, then you probably have a FW issue which is not related to your custom HW.

    Br,
    Igor.

    Thank you for marking the thread as answered if your question was answered :)