STM32f407 isoc transfer was reduced

replicater81 · ‎2015-08-02

Posted on August 02, 2015 at 13:43

Hello all!

I use STM32F4Discovery (embedded code based on HAL v1.6.0) paired with libusbk. To switch on/off the isochronous IN transfer over EP2 i send commands (control transfer) to EP0. The maximum size of EP2 packet was set to 864 bytes. I modified a standart example (Read.Isochronous written on C♯), wich enabled receiving the data from device. After the program was runned first time, the data was received correctly. All transfers was with 864 bytes length. But all other execution of program was bring that all packets are reduced to latest 4 bytes (aligned to four bytes size). I attach the USBlyzer report below.

https://mega.co.nz/♯%217ElSAKyR%21V1mH8a6h_4yPIOCgqscVeB5QctFUpO4s7JqOJLTJ--c

#usb #stm32 #isochronous

Amel NASRI · ‎2015-08-31

Posted on August 31, 2015 at 12:41

Hi replicater,

Having no idea about the code you are running, it is difficult to help you in the problem you are facing.

If you have already fixed the issue you are facing, it may be interesting to other users to know what you did exactly.

-Mayla-

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