USB Interfacing to controllers

I want to connect usb port to the microcontrollers.

as i study a tutorial where they mention we have to add common mode inductor to the DP+ and DM+

But i dont know the Values of inductors..?
How we can calculate..??

Any weblink or articles

Marx

Hi,
First you need to select what USB type: device, host, OTG .
Then you need to choose USB speed.
Then you need to select a USB IC
Then read it's datasheet.
And you should know what signals you want to suppress.

The (single ended) inductance often is not that critical. You need low stray inductance to prevent data transmit problems.
The common mode inductance often is given as common mode impedance at given frequencies. Often you find it in a chart.

Klaus

they mention we have to add common mode inductor to the DP+ and DM+

Click to expand...

Don't believe you'll find an USB controller datasheet requiring common mode chokes as a general design means.

They may be useful in some cases to reduce RF noise emissions. If you have a validated reference design suggesting common mode chokes, it will surely give a component specification.

There are a number of USB to TTL converters available that will connect USB to the receive and transmit pins of a microcontroller's UART. There are converter cables that have the USB chip built into the cable. Arduino uses an ATmega 16U2 as a on board USB to TTL converter. See the Arduino Uno schematic for the design. The USB software for the 16U2 is included with the Arduino software package if one wants to build their own. There are converter boards using chips such as FTDI. All of these are recognized by Linux and Windows (drivers are available), so they are plug and play on a PC. They can communicate using a terminal program like, hyperterminal, Putty or Minicom. They can be used with programs that upload software using an on-chip bootloader, such as Atmel Flip and Pic Tiny bootloader.

@FenTrac do not mess with arduino and uarts (U(S)ARTS a far to slow for USB, and do not think that OP wants to build another VCOM device). Most modern uC (AVR micros are not counted as modern) have USB hardware built in. Te best example is the STM32 family of microcontrollers. The only problem is that you need to implement the USB stack.

@ Bjtpower take $3.4 micro - for example STM32F303CB - and you will only need 4 resistors. I you want to reenumerate your device - another two resistors + one transistor. Schematics - see the ST-Link part of the STM Nucleo boards (files are avaiable from the STM site)

PIC32MX family can do both host and client in the USB mode.
Or even more.
Just use the google search, there are many helpful sites like: https://sites.google.com/site/pcusb...microcontroller-work-as-a-usb-flash-ram-stick

For example:

Using the PIC32MX250F128B as a USB Host to
Interface With Mass Storage Devices

By Douglas Katz and Fred Kummer

Click to expand...

Code and documentation in the attachment:
View attachment PIC32MSDReport.pdf

View attachment PIC32-Mass-Storage.zip


(Sorry for the double post but somehow the forum functionality is broken and I can't edit my yesterdays post)