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RTOS/LAUNCHXL-CC1350: Sensor Node only connects to Collector one time after firmware flashing

Part Number: LAUNCHXL-CC1350
Other Parts Discussed in Thread: CC1350, CC1350STK

Tool/software: TI-RTOS

I am using the CC1350 in coprocessor mode with the prebuilt firmware. This displays a web gui that shows all the sensor nodes. (see attached screenshot)

My sensor nodes (CC1350STK) will connect very fast and work great if I re-flash them with their default firmware immediately after flashing.

However, if I unplug the power to the sensor node and then 2 minutes later reconnect the power, I cannot get that sensor node to connect again.

I'm happy to answer any questions. Any help is appreciated. 

  • Hey Ryan,

    This is probably because the sensorTag nodes are restoring the network information stored in NV when you first connected the device. To clear NV or "Factory Reset" the device hold down the left button on the sensorTag (Right button on a LaunchPad) and power on the device.
  • Hello Brocklobsta,

    I have disabled the NV on my collector, but I didn't know there was NV on the sensor as well.

    However, I'm not sure why the sensor can't keep connecting to the same collector over many power cycles. It should be normal in the field to have the sensor power cycled many times but still be able to reconnect to the same colllector. 

    On the sensor Tag, there are two buttons. Which button I press depends on the orientation of the PCB (which is considered left side or right side, etc). Sadly there are no pictures I have found on the Ti Website and the Quick Start document does not detail this.

    So anyways, I tried both buttons and this did not change anything for me. 

    On the CC1350STK I have a RED LED on constantly on the back of the board (opposite side of PCB from the coin cell). This constant Red LED worries me. Right after I program the flash, the LED is green and operation is proper. Once I power cycle the sensor, I always have a Red LED.

  • Hey Ryan,

    The red LED gets illuminated when the device is in a network. If you power cycle the device and the red LED is illuminated, this means that the device has read network information out of NV. If the collector is also power cycled then the devices will be out of sync (collector doesn't know the sensor is in the network, but the sensor thinks it is still in the network). I suggest turning NV off on both the sensor and collector if you want to form a new network each time. The button you need yo hold down while powering the device on is on the opposite side of the board as the JTAG headers (after powering on with the button pressed the red LED should NOT illuminate). you can also try enabling NV restore on the collector side so the devices will only need to associate once.

    You might want to setup a packet sniffer in order to see the network traffic between the devices, this will let you see what messages are being sent. You can find more information on TI 15.4-Stack and how it works in the Users Guide found here:

  • Hello,

    Please clarify and confirm how to do the following:

    I suggest turning NV off on both the sensor

    I am very clear how to do this on the collector, but I am not sure how to do this on the sensor.

    Thank you,


  • Ryan,

    To enable/disable NV on the linux collector, you can set 'load-nv-sim' to either true or false. On the embedded example applications you can define 'NV_RESTORE' to enable NV. We recommend enabling NV so a network can persist through a power cycle or relaunching the linux demo. To clear NV on the embedded example applications hold the right (btn-2) and reset the device. On the linux collector you can delete the 'nv-simulation.bin' file.

  • Hello,

    Thank you for the info.

    Please define which file the #define NV_RESTORE should go inside of. (or is by default)

    Please let me know if this is enabled by default for some of the CC1350 sensor applications in the SDK.

    Thank you.

  • As I know, it's enable by default. If it doesn't show in your Predefined Symbols, you can add it by yourself.