I have a porblem with the stm32f4 bootloader!
The initialisation of the bootloader via USART1 (PA9/PA10) works so far.
I am using a stm32f4discovery-board. The problem ist that it only works with very low baudrates. I connected PB5, PC11 and PB11 to GND so that none of them toggles. Furthermore I connected BOOT1 to GND and BOOT0 to 3,3 V before entering the bootloader-mode by pulling the NRST-PIN to GND for a short time.
If I send 0x7F with a baudrate of 2400 I recive an ACK (0x79) so there is no problem with flashing.
With a higher baudrate of 4800 it doesn’t send 0x79 as an answer but 0xFE.
Baud 9600: 0xFF
Baud 14400: no response
I supposed there is a problem with the autobaudrateadaption!
Using the bootloader demonstrator:
Baud 2400: recognized device
Until Baud 9600: unrecognized device
From Baud 14400: no response from target
First I used usb-ttl-converter. Using a rs232-ttl-converter didn´t help although I measured the boudrate and it is exact !
So is there a way to increse the possible baudrate? What might be the problem? Thanks for your help!