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Minaihab
Explorer
April 14, 2024
Solved

Issue with HC05 Bluetooth Module Communication When Using External Battery

  • April 14, 2024
  • 2 replies
  • 3644 views

I have a problem in my project involving the STM32L010RB MCU and the HC05 Bluetooth module.

Currently, the system operates smoothly when connected to the USB port. The HC05 Bluetooth module successfully performs its data transmission and reception tasks without any hitches. However, upon introducing an external battery and jumpering pins 2 and 3 on JP5 to provide the Bluetooth module with a 5-volt supply, the module appears to power up correctly, as indicated by the LED, but fails to transmit or receive any data.

I have thoroughly reviewed the connections and power supply, but I have been unable to identify the root cause of this issue.

    This topic has been closed for replies.
    Best answer by Minaihab

    Hello,

    I found the solution to my problem: to start data transmission to or from the Bluetooth module, we should press the reset button on the microcontroller.

    However, I have another problem with ADC 2 and ADC 3. One sensor always gives the maximum reading, and the other has no response, while all the other ADCs work. I am using Tim2 and LPUART.

    2 replies

    M
    Mike_ST
    Technical Moderator
    April 17, 2024

    Hello

    What board is it ?

    Is it a custom board or a Nucleo ?

     

     

      M
      MinaihabAuthor
      Explorer
      April 17, 2024

      Hello,

      Board Nucleo-L010RB 

      A
      Andrew Neil
      Super User
      April 17, 2024
      @Minaihab wrote:

       STM32L010RB MCU and the HC05 Bluetooth module.

      How are they connected - UART?

      Have you looked at what's happening on the (UART?) connecting lines in both the "working" and the "non-working" cases?

       

      What battery are you using?

      Show some good, clear photos of your setup; radio transmitters inherently draw large current peaks, so any issues in the power wiring are likely to disrupt things.

      Try putting a scope on the module's supply pin - is it good and steady? Again, compare  "working" and the "non-working" cases.

       

      EDIT:

      On debugging serial comms:

      https://www.avrfreaks.net/s/topic/a5C3l000000UaFXEA0/t153137?comment=P-1212903

       

        M
        MinaihabAuthor
        Explorer
        April 17, 2024

        We used LPUART in our project.
        Also we used 2 lithium batteries connected in series each 3.7 volts.

        Minaihab_1-1713389813415.png

         

         

        A
        Andrew Neil
        Super User
        April 17, 2024
        @Minaihab wrote:


        Also we used 2 lithium batteries connected in series each 3.7 volts.

        What capacity are those batteries?

        Again:

        • Have you looked at what's happening on the UART connecting lines in both the "working" and the "non-working" cases?
        • Show some good, clear photos of your setup;
        • Try putting a scope on the module's supply pin - is it good and steady? 
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