Error Target MCU stm32f401cd

[yassir]

Salut la communauté,

J'ai créé une carte électronique permettant de visualiser l'état de la batterie d'un ULM. J'ai utilisé le microcontrôleur STM32F401CD, et j'avais initialement prévu d'utiliser uniquement l'horloge interne HSI du MCU, donc je n'ai pas ajouté d'horloge externe. En voulant programmer ma carte, j'ai remarqué que je parviens à effectuer une mise à jour sur mon STM32 Link/v2, mais je n'arrive pas à cibler mon MCU en SWD (qui est correctement alimenté en 3.3V, comme mesuré). Je voulais donc savoir si le problème pourrait venir du HSI.

Merci beaucoup.

[yassir]

Thank you for your Help, i will follow your advices ! 

Can i show you my schematic and give me back some tips or some mistakes that you can find for improve and upgrade my card ? 

[Andrew Neil]

That image is too low resolution to read.

Do you have a PDF, or a high-resolution image?

A description of what it's supposed to do would also help.

[yassir]

Take a look to these document, it's better.

Thank you

[SofLit]

1. Why VDD (pin 36) is not connected to 3.3V?
2. Why VBAT is not connected to VDD?

[yassir]

I thought it wasn't necessary to connect Vbat because I don't use it, and for VDD, i thought that all VDD were connected together inside of the MCU. 

[SofLit]

I thought it wasn't necessary to connect Vbat because I don't use it, and for VDD,

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You need to connect VBAT to VDD if the backup domain is not used. From RM0368 rev 5 / page 72:

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i thought that all VDD were connected together inside of the MCU. 

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You need to connect all the VDD pins to 3.3V. That's why from the beginning I suggested you to refer to the documentations and especially the AN4488.

[yassir]

Yes but I use a battery so i thought it wasn't necessary. Yes for the next version of my card  will use the AN4488 document before.

[SofLit]

Yes but I use a battery so i thought it wasn't necessary. 

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You need to put a jumper of switch on VBAT pin to to select between Battery source or VDD.

This is an example from STM3240G-EVAL board:

[yassir]

Ok I will do this for the future card, so do you think that for my current card, i can't correct problems inside ? 

[Andrew Neil]

I think it's probably best to start again - after thoroughly studying the datasheet, reference manual, application notes (including, but not limited to AN4488), and the dev board schematics.

If you haven't done it before, you should start by prototyping your system on a Nucleo-F401RE:

https://www.st.com/en/evaluation-tools/nucleo-f401re.html

That way you know you are starting with good, known, supported hardware - and that can be a reference for your own design.