6 Replies Latest reply on Jul 18, 2019 10:56 AM by DheerajP_41

    Power current is different between firmware.


      Hi, teams.


      During test with CYBT-213043-MESH board, I found the following.


      • The stacked firmware

      RGB LED is cycling sequentially and print temperature and brightness to peripheral UART periodically.

      I don't know how I can rebuild this firmware.


      • Custom built firmware

      Own built firmware with ModusToolbox 1.1 and BT SDK 1.3, based on BLE_Mesh_SensorTemperature template.

      No LED blinking and different output to peripheral UART.


      When I checked with RF signal analyzer, both firmware send beacon every 30 seconds.

      But, the first one consumes only 2mA, but the second one consumes 5mA.


      I want to know why this difference made, and how can I achieve 2mA current with current development environment.



        • 1. Re: Power current is different between firmware.

          Hi Hyun-ho Choe,


          • "The stacked firmware" -> Do you mean the state before downloading any Mesh application on the board (a fresh board)? If yes, before downloading Mesh application (snip or Demo) you will be able to see RGB led toggling sequentially and, temp and Luminance prints on serial logs, which is a custom non-mesh application to indicate that the board modules are working well and good. I need to check whether this application comes with released SDK or not. May I know why you want to restore the device in this state? When you want to download another mesh application on an existing board you can recover the device by Press Recover - Press Reset - Release Reset - Release Recover button combination and download the firmware.


               Power Consumption

          • TX current consumption

                    BLE silicon: 5.8 mA (radio only, 4 dBm)

          • RX current consumption

                    Bluetooth silicon: 5.9 mA (radio only)

          • Cypress CYW20819 silicon low power mode support

                    PDS: 16.5 uA with 176 KB RAM retention

                    ePDS: 8.7 uA

                    HIDOFF (wake on external or timed interrupt): 1.75 uA


          Please let me know your if you have any queries.




          • 2. Re: Power current is different between firmware.

            I am just interested in the power consumption of this firmware.


            IMO, there is no reason even if the pre-installed firmware is non-mesh application, can use less power than mesh application firmware.

            I have not provisioned the device with new firmware into the mesh network, and both two devices only send beacons for every 30 seconds.

            And according to the peripheral UART, pre-installed firmware is checking two sensors (temperature & Luminance) every few seconds.

            There is no reason the pre-installed firmware uses less current than the new firmware.


            Is there any reasonable explanation why the pre-installed firmware use less power than newer ones?

            If not, please check why it happens, or let me know how to re-build the pre-installed firmware myself, to figure out the difference.


            As you may already know, it is a huge difference between 2mA and 5mA, for the battery-driven devices.

            • 3. Re: Power current is different between firmware.


              Are you use USB power?

              Try to use CR2032.

              I measured pre-installed firmware working current is 6mA.

              • 4. Re: Power current is different between firmware.

                Yes, I tested with power supply.


                Because the overall power will be the same, if the voltage is lower, the current will be higher, I guess.

                But, it is obious that the current is different each other per firmware.


                I want to dig out why.

                • 6. Re: Power current is different between firmware.

                  Hi Hyun-ho Choe,


                  As I explained default firmware on the MESH kit is used for evaluating the hardware on the manufacturing line before they are shipped out. It is not included in the customer release.


                  In unprovisioned state we sent Unprovisioned Device beacons plus Connectable advertisements with Unprovisioned GATT service.  Application is scanning very close to 100%.  So 5mA sounds very reasonable.