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I can't write code to my own STM board


Ekran görüntüsü 2023-12-15 020417.pngWhatsApp Görsel 2023-12-15 saat 01.55.52_01d2e681.jpgWhatsApp Görsel 2023-12-15 saat 01.55.54_2a6b6838.jpg1.pngHello, friends. This is my season project. I am trying to send data and control servo to my stm32f103rbt6 MPU using HC-05. I made this board but I can't write code to my own MPU. Also I can start my bluetooth module in AT mode but I can't find HC-05 on my computer. What is the problem I can't find anything and this is my first project. Thanks for your help.

Pavel A.
Evangelist III

 I made this board but I can't write code to my own MPU.

Yeah, pity. Sometimes even parts of our own body won't obey... this is the life.

So it looks that you use the ST-LINK of a Nucleo-F1 (CN4) to debug your board on the right side? "Can't write code" is not quite a technical description. What do you see in the log? 

I can't find HC-05 on my computer

Again what do you try? This is a very popular device, a lot of guides are available on it. Should be visible by any decent modern Win10 or Win11 PC with Bluetooth.


ST Employee

Hell @bbayrm ,

Very vague description of the issue.. 

When you said: "I can't write code to my own STM board" do you mean you can't connect to the device? or what?

What tools you are using?

Regarding your hardware:

Did you follow the recommendations provided in the AN2586 "Getting started with STM32F10xxx hardware development"? I'm not seeing decoupling capacitors in you schematics, even there are some soldered on your PCB. You have to check this point.

Also, and sorry, I'm not very comfortable with your soldering quality especially the power part 😉!

To give better visibility on the answered topics, please click on "Accept as Solution" on the reply which solved your issue or answered your question.
Bob S

If you are trying to use the STLink built in to the NUCLEO board to debug an external CPU, you need to change a couple of jumpers. CN2 has 2 shorting clips on it.  If you look at the silkscreen, with shorting clips on it sends SWD signals to the on-board F103.  If you remove those two, the SWD signals are available on the header that you have your wires on.  There may be other changes you need to make.  It has been a while since I've done that.  Get the manual for the NUCLEO-F103 board and see what it says.

This - Remove CN2 jumpers, they create connectivity to the Local Target's SWDIO / SWCLK, and you want the Off-Board Target, with the jumpers in place the two will clash.

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