can not detect olimex STM32-H107 Virtual Port

[saimaddy123]

Posted on March 14, 2011 at 06:24

can not detect olimex STM32-H107 Virtual Port

[tsuneo]

Posted on May 17, 2011 at 14:27

Here is the schematic of Olimex STM32-H107 board

http://www.olimex.com/dev/pdf/ARM/ST/STM32-H107-schematic.pdf

Is R34 populated on your board?

The schematic shows it as NA

This resistor connects MCU PA9/OTG_FS_VBUS pin to the USB connector VBUS pin.

The OTG engine requires this connection to enable on-chip D+ pull-up resistor automatically at plug-in.

> the device is not detected on windows XP first

 

It suggests that the D+ pull-up resistor is not enabled.

So, I have doubt on the R34 resistor. 

Tsuneo

[tsuneo]

Posted on May 17, 2011 at 14:27

> But, D+ pull-up resistor is connected to PA12 of MCU.

This OTG engine has on-chip pull-up resistor(s). You don't need any external one.

> I am setting this GPIO pin so that D+ pull-up resistor is enabled. Still, I could see that the device is not getting detected..

Check the voltage of D+ and D- lines. Do you see the pull-up voltage at one of these lines?

As Windows don't tell any USB hardware connection, I believe these lines are kept in low.

Maybe, the connection routine, which enables the external pull-up, is not called on your firmware.

Did you change the processor type on the header file, as follows?

The default is STM32F10X_XL. For STM32F107, STM32F10X_CL is chosen.

Or, as the tips suggests, add this definition to the compile option.

----------------- excerpt from the source code, from here ----------------

\Libraries\CMSIS\CM3\DeviceSupport\ST\STM32F10x\stm32f10x.h

/* Uncomment the line below according to the target STM32 device used in your

   application 

  */

#if !defined (STM32F10X_LD) && !defined (STM32F10X_LD_VL) && !defined (STM32F10X_MD) && !defined (STM32F10X_MD_VL) && !defined (STM32F10X_HD) && !defined (STM32F10X_XL) && !defined (STM32F10X_CL) 

  /* #define STM32F10X_LD */     /*!< STM32F10X_LD: STM32 Low density devices */

  /* #define STM32F10X_LD_VL */  /*!< STM32F10X_LD_VL: STM32 Low density Value Line devices */  

  /* #define STM32F10X_MD */     /*!< STM32F10X_MD: STM32 Medium density devices */

  /* #define STM32F10X_MD_VL */  /*!< STM32F10X_MD_VL: STM32 Medium density Value Line devices */  

  /* #define STM32F10X_HD */     /*!< STM32F10X_HD: STM32 High density devices */

//   #define STM32F10X_XL      /*!< STM32F10X_XL: STM32 XL-density devices */       // <------ comment this line

   #define STM32F10X_CL      /*!< STM32F10X_CL: STM32 Connectivity line devices */  // <------ recover this line

#endif

/*  Tip: To avoid modifying this file each time you need to switch between these

        devices, you can define the device in your toolchain compiler preprocessor.

----------------- to here ----------------

Tsuneo

[saimaddy123]

Posted on May 17, 2011 at 14:27

Tsuneo,

Thanks for the reply,, You are right R34 is not populated. But, D+ pull-up resistor is connected to PA12 of MCU. I am setting this GPIO pin so that D+ pull-up resistor is enabled. Still, I could see that the device is not getting detected...

Is n't it the case that we can drive it without R34 also?

Thanks,

Sai

[saimaddy123]

Posted on May 17, 2011 at 14:27

Tsueno,

I could have the USB port working by putting PA11 and PA12 to BIT_RESET. You are right that those pull-up resisters are inside OTG. As the lines are multiplexed between PA11/USART/OTG_FS_DP, i disabled PA11 (and USART lines are not connected on this board), so that connected OTG_FS_DP to D+. So, I could detect it finally and Windows Recognizes it as Virtual COM port..

The tool chain I am using(CrossWorks) automatically selects STM32F10X_CL as build option for STM32F107.

I have different set of problems now.. I will post a different topic for that..

Thanks,

Sai