[StabiloRose] VBUS

Today, we started to code for our board. The switching power supplies are working well and controlled by the STM32. Interrupts are generated if they are not stable. Everything went fine… Until we tried to implement the serial over USB module, and the shell. We were stuck for a loooooong moment. Impossible to obtain anything. It was like the STM32 was not connected to the laptop. We confirmed that it was not an hardware issue by communicating with the preinstalled USB bootloader of the STM32.

After checking the schematic, we (Thanks for all Dryvenn) pointed out the problem. The PA9 is the default pin for VBUS. Ours is connected to the buzzer, with a pull-down resistor. As the STM32 couldn’t detect if any cable was plug-in, it have never engaged the communication.

The problem is solved by defining the symbol BOARD_OTG_NOVBUSSENS in board.h. Now we have to manage the cable detection “manually” with interrupts.

 

Practical work

The diagram of our project is almost finished. Today, I have seen with Alexis what I have had to do with Vbus from the USB. We don’t use usb to supply our pcb however the STM32 need to be connected with the Vbus in order to know that there is a USB connection. I have changed the diagram.

I was working on the practical work. I have succeed to debug the demos application. Now, I am playing with LED’s. I have got just one problem. Firstly, I have forgot to press the reset button and nothing have worked.

Eric