Hello Community!
I have a project where I was using a STM32F407 MCU from a minimal ready-to-run system with USB, programming connection and pin headers to access every MCU pin. While using this hardware, the project can be loaded and executed on the MCU.
However, to improve the hardware solution I integrated all these features in my own PCB and buy the MCU. The problem is that when connecting it for the very first time to STM32CubeProgrammer the system does not find the target at all.
I have checked the following things on the MCU pins:
- Power supply 3.3V is OK
- MCU current consumption is in the order of uA, lower than the specified by STM in the hardest Energy Saving mode.
- Continuity from MCU pins and Progrrammer connector is OK
- Clock signal from ST-Link Device is properly reaching the MCU.
- Boot pins are properly managed by the programmer
The error raised by the STM32CubeProgrammer is the same as if there were no MCU connected: NO STM TARGET FOUND!
I bought a batch of 10 MCUs and the error is the same on the 4 different MCUs that I checked, also on PCBs from different manufacturers.
So far, I want to ask to the community the following:
- Is there any special status in which the MCUs are sent from factory that must be change before the very first programming? If yes, which is the procedure?
- Can you suggest me other points to check to validate the correct mounting and that the connection between ST-Link and MCU is OK?
Thank you all in advance for your help, I will appretiate your answers a lot.
