USB Host Shield 2.0
USB Host Library Rev. 2.0

The code is released under the GNU General Public License.


This is Revision 2.0 of MAX3421E-based USB Host Shield Library for AVR's.

Project main web site is:

Some information can also be found at:

The shield can be purchased from TKJ Electronics:

USB Host Shield

For more information about the hardware see the Hardware Manual.

Developed By

Table of Contents

How to include the library

Arduino Library Manager

First install Arduino IDE version 1.6.2 or newer, then simply use the Arduino Library Manager to install the library.

Please see the following page for instructions:

Manual installation

First download the library by clicking on the following link:

Then uncompress the zip folder and rename the directory to "USB\_Host\_Shield\_20", as any special characters are not supported by the Arduino IDE.

Now open up the Arduino IDE and open "File>Preferences". There you will see the location of your sketchbook. Open that directory and create a directory called "libraries" inside that directory. Now move the "USB\_Host\_Shield\_20" directory to the "libraries" directory.

The final structure should look like this:

Now quit the Arduino IDE and reopen it.

Now you should be able to go open all the examples codes by navigating to "File>Examples>USB\_Host\_Shield\_20" and then select the example you will like to open.

For more information visit the following sites: and

How to use the library


Documentation for the library can be found at the following link:

Enable debugging

By default serial debugging is disabled. To turn it on simply change ENABLE_UHS_DEBUGGING to 1 in settings.h like so:



Currently the following boards are supported by the library:

The following boards need to be activated manually in settings.h:

Simply set the corresponding value to 1 instead of 0.

Bluetooth libraries

The BTD library is a general purpose library for an ordinary Bluetooth dongle. This library make it easy to add support for different Bluetooth services like a PS3 or a Wii controller or SPP which is a virtual serial port via Bluetooth. Some different examples can be found in the example directory.

The BTD library also makes it possible to use multiple services at once, the following example sketch is an example of this: PS3SPP.ino.

BTHID library

The Bluetooth HID library allows you to connect HID devices via Bluetooth to the USB Host Shield.

Currently HID mice and keyboards are supported.

It uses the standard Boot protocol by default, but it is also able to use the Report protocol as well. You would simply have to call setProtocolMode() and then parse HID_RPT_PROTOCOL as an argument. You will then have to modify the parser for your device. See the example: BTHID.ino for more information.

The PS4 library also uses this class to handle all Bluetooth communication.

For information see the following blog post:

SPP library

SPP stands for "Serial Port Profile" and is a Bluetooth protocol that implements a virtual comport which allows you to send data back and forth from your computer/phone to your Arduino via Bluetooth. It has been tested successfully on Windows, Mac OS X, Linux, and Android.

Take a look at the SPP.ino example for more information.

More information can be found at these blog posts:

To implement the SPP protocol I used a Bluetooth sniffing tool called PacketLogger developed by Apple. It enables me to see the Bluetooth communication between my Mac and any device.

PS4 Library

The PS4BT library is split up into the PS4BT and the PS4USB library. These allow you to use the Sony PS4 controller via Bluetooth and USB.

The PS4BT.ino and PS4USB.ino examples shows how to easily read the buttons, joysticks, touchpad and IMU on the controller via Bluetooth and USB respectively. It is also possible to control the rumble and light on the controller and get the battery level.

Before you can use the PS4 controller via Bluetooth you will need to pair with it.

Simply create the PS4BT instance like so: PS4BT PS4(&Btd, PAIR); and then hold down the Share button and then hold down the PS without releasing the Share button. The PS4 controller will then start to blink rapidly indicating that it is in pairing mode.

It should then automatically pair the dongle with your controller. This only have to be done once.

For information see the following blog post:

Also check out this excellent Wiki by Frank Zhao about the PS4 controller: and this Linux driver:

Several guides on how to use the PS4 library has been written by Dr. James E. Barger and are available at the following link:

PS3 Library

These libraries consist of the PS3BT and PS3USB. These libraries allows you to use a Dualshock 3, Navigation or a Motion controller with the USB Host Shield both via Bluetooth and USB.

In order to use your Playstation controller via Bluetooth you have to set the Bluetooth address of the dongle internally to your PS3 Controller. This can be achieved by first plugging in the Bluetooth dongle and wait a few seconds. Now plug in the controller via USB and wait until the LEDs start to flash. The library has now written the Bluetooth address of the dongle to the PS3 controller.

Finally simply plug in the Bluetooth dongle again and press PS on the PS3 controller. After a few seconds it should be connected to the dongle and ready to use.

Note: You will have to plug in the Bluetooth dongle before connecting the controller, as the library needs to read the address of the dongle. Alternatively you could set it in code like so: PS3BT.ino::L20.

For more information about the PS3 protocol see the official wiki:

Also take a look at the blog posts:

A special thanks go to the following people:

  1. Richard Ibbotson who made this excellent guide:
  2. Tomoyuki Tanaka for releasing his code for the Arduino USB Host shield connected to the wiimote:

Also a big thanks all the people behind these sites about the Motion controller:

Xbox Libraries

The library supports both the original Xbox controller via USB and the Xbox 360 controller both via USB and wirelessly.

Xbox library

The XBOXOLD class implements support for the original Xbox controller via USB.

All the information are from the following sites:

Xbox 360 Library

The library support one Xbox 360 via USB or up to four Xbox 360 controllers wirelessly by using a Xbox 360 wireless receiver.

To use it via USB use the XBOXUSB library or to use it wirelessly use the XBOXRECV library.

Note that a Wireless controller can NOT be used via USB!

Examples code can be found in the examples directory.

Also see the following blog posts:

All the information regarding the Xbox 360 controller protocol are form these sites:

Xbox ONE Library

A Xbox ONE controller is supported via USB in the XBOXONE class. It is heavily based on the 360 library above. In addition to cross referencing the above, information on the protocol was found at:

Xbox ONE S Library

A Xbox ONE controller is supported via Bluetooth in the XBOXONESBT class.

Special thanks to HisashiKato for his help:

Wii library

The Wii library support the Wiimote, but also the Nunchuch and Motion Plus extensions via Bluetooth. The Wii U Pro Controller and Wii Balance Board are also supported via Bluetooth.

First you have to pair with the controller, this is done automatically by the library if you create the instance like so:

WII Wii(&Btd, PAIR);

And then press 1 & 2 at once on the Wiimote or the SYNC buttons if you are using a Wii U Pro Controller or a Wii Balance Board.

After that you can simply create the instance like so:

WII Wii(&Btd);

Then just press any button on the Wiimote and it will then connect to the dongle.

Take a look at the example for more information: Wii.ino.

Also take a look at the blog post:

The Wii IR camera can also be used, but you will have to activate the code for it manually as it is quite large. Simply set ENABLE_WII_IR_CAMERA to 1 in settings.h.

The WiiIRCamera.ino example shows how it can be used.

All the information about the Wii controllers are from these sites:

PS Buzz Library

This library implements support for the Playstation Buzz controllers via USB.

It is essentially just a wrapper around the HIDUniversal which takes care of the initializing and reading of the controllers. The PSBuzz class simply inherits this and parses the data, so it is easy for users to read the buttons and turn the big red button on the controllers on and off.

The example PSBuzz.ino shows how one can do this with just a few lines of code.

More information about the controller can be found at the following sites:

HID Libraries

HID devices are also supported by the library. However these require you to write your own driver. A few example are provided in the examples/HID directory. Including an example for the SteelSeries SRW-S1 Steering Wheel.

MIDI Library

The library support MIDI devices. You can convert USB MIDI keyboard to legacy serial MIDI.

For information see the following page:

Interface modifications

The shield is using SPI for communicating with the MAX3421E USB host controller. It uses the SCK, MISO and MOSI pins via the ICSP on your board.

Note this means that it uses pin 13, 12, 11 on an Arduino Uno, so these pins can not be used for anything else than SPI communication!

Furthermore it uses one pin as SS and one INT pin. These are by default located on pin 10 and 9 respectively. They can easily be reconfigured in case you need to use them for something else by cutting the jumper on the shield and then solder a wire from the pad to the new pin.

After that you need modify the following entry in UsbCore.h:

typedef MAX3421e<P10, P9> MAX3421E;

For instance if you have rerouted SS to pin 7 it should read:

typedef MAX3421e<P7, P9> MAX3421E;

See the "Interface modifications" section in the hardware manual for more information.


When I plug my device into the USB connector nothing happens?

When I connecting my PS3 controller I get a output like this:

Dualshock 3 Controller Enabled
LeftHatX: 0 LeftHatY: 0 RightHatX: 0 RightHatY: 0
LeftHatX: 0 LeftHatY: 0 RightHatX: 0 RightHatY: 0
LeftHatX: 0 LeftHatY: 0 RightHatX: 0 RightHatY: 0
LeftHatX: 0 LeftHatY: 0 RightHatX: 0 RightHatY: 0
LeftHatX: 0 LeftHatY: 0 RightHatX: 0 RightHatY: 0

When compiling I am getting the following error: "fatal error: SPI.h: No such file or directory".