I'm building a project that will connect to users' phones (Android at first, but iPhone too, if there's enough interest) via USB. Of course, this means that I need a USB host in the project. The total size of the device has to be about the size of the phone, so answers that seriously suggest shields aren't going to be helpful - they'd put me over my size budget by at least a factor of 3.

I'd also rather not require an adapter to go from the USB Mini B connector type to the Micro B connector type.

Gravitech has a USB Host board for the Nano 3 that has a USB Type A connector, and the combination of a Nano and Gravitech Host is about the right size (maybe a little thick, once the whole thing is soldered to my own board), but the USB host is $25. I can get the Nano for about $4 each and would like to keep the USB host in the neighborhood of $8 each. Are the solder fumes getting to me, or is there such a specimen out there and I'm just not finding it?

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    Why not go with bluetooth?
    – Gerben
    Feb 24, 2015 at 10:57
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    I'm uncertain of what you mean by "USB host". Do you wish to be able to plug the Arduino into the phone's USB port and interact with it via USB or GSm or WiFi or ... ...? Feb 24, 2015 at 11:04
  • Your requirement would probably be better met by something that isn't an Arduino at all, and has native USB host. Feb 24, 2015 at 12:05
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    Atmel has AVRs with USB OTG support perhaps one of those would work.
    – Craig
    Feb 24, 2015 at 15:06
  • In the non-Arduino realm, I've had success with both STM32F401/411 Nucleos and the Kinetis KL25Z freedom board. Those are all in the $10-12 range and slightly larger than an Arduino, but I've also made the corresponding chips work on smaller custom boards. A KL25Z64 is just over $3 in a QFN32 package, though it needs another crystal and requires skill to solder (if space is not an extreme concern, the QFP48 will be easier to work with). Jun 11, 2015 at 14:25

2 Answers 2


The Arduino Due and Arduino Mega ADK can both serve as a USB Host. You can also use the chip that the Mega uses yourself

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    No, the Arduino Mega is not a USB host (perhaps you confused the Mega for the ADK?). You can of course add an embedded USB host chip to a Mega, but it is probably not cost effective to do so compared to devices which have that natively. The Due, while still overpriced, is comparatively a good deal since it costs less than a board + host shield and is in the class of things which are far more capable as computational platforms (but still twice what you need to spend on hardware to do this). Feb 25, 2015 at 2:53
  • Thanks for clarifying. I guess I misinterpreted when I read about the Mega. Feb 25, 2015 at 20:40
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    I think you were probably looking at the Mega ADK - not particularly small or cheap -arduino.cc/en/Main/ArduinoBoardMegaADK Feb 25, 2015 at 21:13

Cypress makes very small usb chips capable of host mode. Does this board meet your size requirements? http://www.mouser.com/ProductDetail/Cypress-Semiconductor/CY8CKIT-049-41XX/?qs=FSHIiqjonm0YmFbmBQfo1A%3D%3D&kpid=1159933375&gclid=CPjl6KOm4cQCFYGUfgodJh4A_g

You may also consider ditching the arduino and running everything on the cypress

  • Are you sure that the board you link can do this? Cypress' own documentation lists the CY8C4125AXI-483 and CY8C4245AXI-483 offered on those kits as being without a USB interface while I'm not seeing any indication that the interface IC can function as anything other than a device. Cheap alternative to an Arduino or USB-serial, yes,. But apparently not a host solution. Jun 11, 2015 at 14:17

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