@VasVar wrote:
a Bluetooth module (HC-05 or HC-06) ?
Note that these are not ST products.
They connect to a microcontroller - any microcontroller - using a UART (serial) interface. They neither know nor care what microcontroller you use.
So, as far as the STM32 is concerned, this is just standard UART comms.
If you're not already familiar with UART comms on STM32, then start by getting it working with a terminal on a PC.
https://wiki.st.com/stm32mcu/wiki/Getting_started_with_UART
https://community.st.com/t5/stm32-mcus/implementing-uart-receive-and-transmit-functions-on-an-stm32/ta-p/694926
Similarly, familiarise yourself with the HC-05/6 and its operation by getting it working with a terminal on a PC.
@VasVar wrote:
What is the recommended way to connect an HC-05/HC-06 module to the NUCLEO-F401RE when the X-NUCLEO-53L7A1 expansion board is mounted?
The X-NUCLEO-53L7A1 is immaterial to the HC-05/6 connection - just make sure that there are no pin conflicts.
Also check that the total power consumption is within the Nucleo board's capabilities.
@VasVar wrote:
2. Are there any potential hardware conflicts (e.g., UART pin usage, power supply limitations, or pin mapping issues)?
It's up to you to ensure that there are no conflicts - see the documentation for the various boards for details.
For the ST Boards, there will be a User Manual in the 'Documentation' tab of the Product Page; eg,
https://www.st.com/en/evaluation-tools/x-nucleo-53l7a1.html#documentation
There will also be schematics on the 'CAD Resources' tab; eg,
https://www.st.com/en/evaluation-tools/nucleo-f401re.html#cad-resources
How to interface anything to anything else
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.
