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.

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

Other Parts Discussed in Thread: CC2540

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!

  • Hello,

    Did you modify the Advertisement data or Scan Response data? Likely there is something in the logical data that is preventing the phone from displaying the device. I would use the sniffer to review the Advertisement data.

    Best wishes
  • Try to install bluez on linux machine and try to sniff the ADV data. If Adv is not standard, then phone will not recognize your device
  • I didn't change anything I just downloaded the original SimpleBLEPeripheral program provided in the BLE stack 1.3.2 and tried to verify my design. And I'll try to use sniffer to verify the Advertisement data. I'll let you know after my test. Thanks for your quick reply!
  • Let me install Linux on my laptop first XD. By the way what's the difference between TI's sniffer and this bluez? Thanks in advance!
  • I tried TI package sniffer software along with  cc2540 dongle. The advertisement from my device running the SimpleBLEPeripheral is the same as the that from Sensortag running the same program(I downloaded the SimpleBLEPeripheral to the sensortag with LED and LCD disabled.) My iPhone sent scan request to the Sensortag but not my device, as shown below. Sensor Tag has an address as 1C BA 8C 20 C3 67. My device is D0 5F B8 52 FA 34.

    Is there any possibility that this is result from a hardware issue? My design uses an unmatched dipole antenna. However, the signal strength is good, saying with an RSSI of -38dBm.

  • Hello,

    To rule out an antenna issue, you would need to do a conducted RF-PHY test. You'll have to do this test anyway to get BT qualified. However, the sniffer doesn't not detect any issues, so it's not clear why it's not showing up in your phone. Have you tried using the TI SensorTag app or Light Blue on iOS?

    Best wishes
  • When I looked the log of sniffer again, I found that, in the time column, all the "+" number for my device "D0 5F B8 52 FA 34" is huge, all 90K above. Does it imply anything? Besides, I remove the load caps connected to the 32 MHz crystal to save space. Can those missing caps be a cause?

    Best regards