STM32F407 USB Host config for FT232RL

SohamC · ‎2025-09-22

Title edited to name the device being hosted.

Hello ,
I am currently trying to configure STM32F407 board as USB host. The code for it is given below. I am not receiving anything from the USB device(bus powered). I have a doubt that it might be related to the hardware of it(VBUS). The rest of the code is generated by the IDE itself so there is no doubt related to it. I have configured it as USB host only mode. I am new to embedded systems so any kind of help would be appreciated. Is there anything wrong with the code or any links to help me configure the USB host.
I would be glad to clarify any queries related to the above.

Andrew Neil · ‎2025-09-22

welcome to the forum.

Please see How to write your question to maximize your chances to find a solution for best results.

In particular, what STM32F407 board are you using, and what is the USB device?

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

SohamC · ‎2025-09-22

STM32F407ZGT6 , and the USB device is USB to serial converter FT232RL chip(which expects power from the bus).
Does this help?

waclawek.jan · ‎2025-09-22

> the USB device is USB to serial converter FT232RL chip

That's not a standard CDC class device, look at its descriptors. You would need a custom driver for it.

JW

FBL · ‎2025-09-23

Hi @SohamC

Do you reproduce the issue using STM32F4DISCOVERY board? If so, have you tried the firmware example provided here. Then you can check host applications and dive deeper into requirements of host application. This section in wiki might be helpful as well.

To give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.

SohamC · ‎2025-09-23

Thank you for the clarification, so what method would you suggest to establish communication with this chip?

waclawek.jan · ‎2025-09-23

As I've said, you'd need a custom driver for it. Maybe there is some vendor out there who offers that (maybe even FTDI, try asking them); or maybe the protocol is available and then you can implement it yourself.

JW

Andrew Neil · ‎2025-09-23

Have you tried an internet search for "Microcontroller Host FT232" ?

First hit I get with that is: STM32 USB Host. Virtual Port Com. FTDI and CH340

Which confirms what @waclawek.jan said ...

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.