USB device and USB host

[TiagoRibeiro]

Hello everyone,=D
I would like to know the difference between usb host and usb device. What types of devices use? Anyone know any datasheet that explains all about it? How to use them in the development of hardware?

 

[xpress_embedo]

I am giving you a simple example.

Computer (PC) is a host, and whatever USB device that can be connected to PC USB port are USB devices.

You can connect many USB devices to a Host (Limited).

One more example.
Tablet when connected to PC behaves as a USB device and when a Pen Drive is connected to a tab it behaves as USB Host for that.

What type of hardware you want to make???
There are lots of micro-controller available in the market and are easy to use, i had used one PIC32MX795F512L from microchip family.

https://electronics.stackexchange.c...-the-difference-between-a-usb-host-and-device

 

[TiagoRibeiro]

Hello, thanks for reply. :grin:
What I am developing is a hardware that uses an ARM Cortex processor, and need to include a USB Bluetooth module, Wi-Fi, one USB for charging and data transfer.

 

[component_inc]

1) USB to host allows you to connect a computer to the DP.
2) USB to device allows you to connect a flash drive or memory card reader to the DP.

 

[TiagoRibeiro]

Got it, but electrically, how each port behaves? Means that only the host USB supply voltage for the devices? But if a tablet behaves as host for a pendrive, how it behaves like a device to pc? Is there any internal switching?
Hope you understand.:wink:

 

[MrPopples]

you might want to check this: https://en.wikipedia.org/wiki/USB_On-The-Go

usb OTG has a supplementary pin, which indicates to the controller how to behave (host or device).
The status of the pin is "hard wired" in the connectors.
if you look at your phone to pc connector, you'll see that it is labeled "A" on PC side and "B" on phone side.
this tells the phone to act like a device.

if you plug a "A" connector to your phone, it will act like a host.

and yes, the Host supplies the VBUS... but not only, read the usb electrical specification for (far more) details.

 

[TiagoRibeiro]

Thank you, clearly explained