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Minaihab
Associate II
April 14, 2024
Solved

Issue with HC05 Bluetooth Module Communication When Using External Battery

  • April 14, 2024
  • 9 replies
  • 3712 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.

9 replies

Mike_ST
Mike_ST
ST Technical Moderator
April 17, 2024

Hello

What board is it ?

Is it a custom board or a Nucleo ?

 

 

In order to give better visibility on the answered topics, please click on 'Best answer' on the reply which solved your issue or answered your question. 
    MinaihabAuthor
    Associate II
    April 17, 2024

    Hello,

    Board Nucleo-L010RB 

    Andrew Neil
    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

     

    A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
      MinaihabAuthor
      Associate II
      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

       

       

      Andrew Neil
      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? 
      A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
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