Is there any way to set a specific GPIO high when entered a bootloader

[EGinz.1]

I am programming the uC via UART that is connected via a Transceiver. The transceiver has an DE (Driver Enable) pin which is active high. Unfortunately, it has a pull down instead of pull-up in a design, therefor the uC can hear but can't talk back. This pin (DE) is also connected to one of the uC GPIOs. If only I could set this pin high by sending something to the uC when its in the boot-loader mode.., can I?

Other thought would be to force the STM32Cube to connect.. as off it has received the 0x7F from the uart.

Please help.

[waclawek.jan]

> Is there any way to set a specific GPIO high when entered a bootloader

No. You have to fix the hardware.

JW

[Ozone]

If you mean the ROM-based system bootloader, the answer is no.

But perhaps you can override the DE pin of your transceiver module with a pull-up, which you can later disable (or reset) from within your application.

Or skip the system BL alltogether, and use your own.