Bootloader-RS485

[DeveloperMan]

Hello there,

I want to load the application code with the bootloader over the RS-485 line using stm32f103 in my project. I did this over the RS-232 line. However, I could not achieve this with the RS-485 line.

[Tesla DeLorean]

I wouldn't expect the ROM based system loader to be able to support this mode of connection.

You'll need to code your own loader with awareness of your hardware design.

[DeveloperMan]

I can boot the software with Real-Term via the CPU's usart1 pins (Tx-Rx). However, there is an RS-485 integrated in my hardware and there is a conversion with the A-B line. In order to turn this hardware into software, I need to configure it over the enable pin.

[TDK]

The STM32F1 doesn't have native support for RS-232 or RS-485. You'll need a transceiver chip to convert it to a single ended signal and hook it up to one of the UART ports supported by the bootloader.

[DeveloperMan]

What exactly do you mean by the transceiver chip?

[prain]

You can use a custom Bootloader to achieve this.

The default ST Bootloader work in full duplex mode​, so you can use RS422 instead.

[DeveloperMan]

I can boot the software with Real-Term via the CPU's usart1 pins (Tx-Rx). However, there is an RS-485 integrated in my hardware and there is a conversion with the A-B line. In order to turn this hardware into software, I need to configure it over the enable pin.