STM32F072 USBD_LL_Transmit problem

[martintramsak9]

Posted on July 01, 2016 at 11:04

I'm using STM32F072 MCU in USB Device mode. The USB enumerates nicely creating 1 interface and 2 bulk endpoints. One input and one output. Both with the maximum transfer size 64 bytes.

The problem occurs when I try to transfer more than 16 bytes of data. The transfer data is OK when I transfer less than 16 bytes but gibberish when I transfer more than 16 bytes in a single packet. I am analyzing the stream on a USB analyzer. 

I have opened the endpoints and I transfer data with USBD_LL_Transmit function. 

I am using HAL libraries

Any ideas what I am doing wrong ?

#stmf0 #hal #usb #usb #stm32f0

[tsuneo]

Posted on July 02, 2016 at 13:56

Hi martin,

Sound like a problem around assignment of endpoint buffer address for the bulk endpoint, using HAL_PCDEx_PMAConfig().

Using ''search files'' function of your editor, find code lines like this one,

  HAL_PCDEx_PMAConfig(&hpcd , 0x00 , PCD_SNG_BUF, 0x18);     // EP0 OUT

  HAL_PCDEx_PMAConfig(&hpcd , 0x80 , PCD_SNG_BUF, 0x58);     // EP0 IN

  HAL_PCDEx_PMAConfig(&hpcd , 0x01 , PCD_SNG_BUF, 0x100);    // EP1 OUT

  HAL_PCDEx_PMAConfig(&hpcd , 0x81 , PCD_SNG_BUF, 0x140);    // EP1 IN

HAL_PCDEx_PMAConfig() assigns starting address of endpoint buffer on USB RAM to each endpoint.

- You should have four lines of HAL_PCDEx_PMAConfig(), for the default EPs (EP0 IN/OUT) and the two bulk EPs.

Above example assumes EP1 IN/OUT for the bulk EPs. To keep 64 bytes buffer for EP1 OUT (starting at 0x100), EP1 IN starts at 0x140. Modify your code like above one.

Tsuneo

[yshen.6]

I Modify my code like above,but the  problem also occurs .what can i do ? the mcu is stm32l433rct.