✏ FP2 : USB device compatibility

Hello all !

We already discussed in another thread the very cool feature of the FP2 that its hardware support USB on-the-go.
That means, with the right cable (few € on ebay), you can plug any USB device as you would do on a PC.
Though, be aware that it might suck a lot from your battery, and since it uses the USB port you can’t do this and charge your phone at the same time.

You will find down here the results of community experiments. Done with the out-of-the-box regular FP OS, so note that :

  • it might be possible to extend capabilities with a custom compiled OS.
  • any device not working out of the box with the standard OS, does not mean impossible. We would need either external power source (very easy), finding or developping an android app (easy) or a kernel driver (uneasy, needs custom OS compiling or asking FP to include it in the OSOS)


###:white_check_mark: USB stick
Plug it and open the Amaze file manager, and choose ‘usbotg’. You can do anything thinkable, copy files, play movies…

###:negative_squared_cross_mark: External hard disk
Obviously this would need more power. I guess it might work with a powered USB hub.

##HID devices

###:white_check_mark: Mouse
You get a pointer appearing on the screen and can point’n’click in a traditional fashion. @TobiasF also reported this to work.

###:white_check_mark: Keyboard
You get a new input method, and you can use a real full sized keyboard for your SMS or Whatsapp sessions :slight_smile: or whatever involving typing.
You can go to input method settings to select your keyboard layout (azerty, qwertz…)
A cool feature is that you get some shortcuts working : alt-tab for app switch, printscreen for screenshot, F3 to search, page up/down to scroll, ctrl-XCV for copy/paste, and I think many others

##Game controllers

###:white_check_mark: SmartJOY
Smart joy is a super nintendo to USB adapter.
I am a retro gamer… And now I can use my old days SNES controller, and play super mario world on my phone with the REAL controller in hand !! wicked ! :slight_smile: Tested and works with snes9x EX+.
It’s WAY better than playing with on-screen touch controls.
Didn’t test with other apps.

###:negative_squared_cross_mark: Generic gamepad
I have a very basic gamepad provided with my internet box (freebox)
It is not recognized, the LED doesnt light up.

###:negative_squared_cross_mark: Xbox gamepad
Not standard compliant, I think it would need a specific driver.
On linux it can be done with ‘xpad’ kernel module. OS compiling anyone ?


###:white_check_mark: PCM2704-powered sound-card
Reported by @retsifp. At least 3.5mm output works, and the three buttons (vol +/-, mute) are active.
TOSLINK and S/PDIF outputs untested, but likely to work.
###:white_check_mark: HiFime DIY 9018D
###:white_check_mark:Focal XS speakers
Includes an USB sound card. Reported working by @diegotascon
###:white_check_mark:Phillips AS360
Officially only supports analog Jack and bluetooth
But reported working via USB by @diegotascon
###:white_check_mark: MIDI over USB
Apps like ‘Midi monitor’ or ‘Midi commander’ can receive MIDI data from my controller.
I didn’t find a way to create a mapping for a DJ software and actually use it, but at least the MIDI interface works and raw messages are logged.
There are many synth apps, so if you have a midi piano keyboard you might be able to use it easily.
###:negative_squared_cross_mark: AudioQuest DragonFly
not working (external audio DAC ; a new material version is announced “soon to be released” by AudioQuest last january)
This could be a power issue.
###:negative_squared_cross_mark: Traktor Audio DJ 2
Would also need a specific kernel module, snd-usb-caiaq

Basically any USB printer should work as long as the vendor offers an SDK (“driver”) for the printer model.
Successfully tested were some POS (receipt) printers, the respective SDKs support many other models.
###:white_check_mark: [POS] Epson TM-T20II
###:white_check_mark: [POS] Star TSP100
###:white_check_mark: [POS] Custom TL60

##Card readers

###:white_check_mark: Smart card reader
It’s possible to use a CCID compliant card reader.
I used the ‘Smart Card Toolkit’ app, and could read my credit card with a Gemalto Prox USB reader.
Its a combo reader, It could both use contact (chip) and contactless.
Note that AFAIK, CCID cannot read NFC cards, it would require a different reader.

###:white_check_mark: IZettle payment terminal
Actually not an USB device, because it connects on the audio Jack.
But it might be useful to mention here that it does work on the FP2.

##SDR (Software Defined Radio)
Recommended receiver software: Dennis Mantz’s RF Analyzer from F-Droid or Google Play
More info about SDR can be found here: http://www.rtl-sdr.com/
###:white_check_mark: HackRF One
HackRF One only tested as receiver. Transmit mode untested because no software available for Android.
###:white_check_mark: RTL-SDR (RTL2832U based USB Digital TV Dongles).
Martin Marinovs RTL2832U driver from F-Droid or Google Play is required for these to work.


###:white_check_mark: “Seek” Thermal Camera Module
Camera faces the right direction and there is no need for an adapter.

###:negative_squared_cross_mark: SCL3711 NFC stick
Not recognized by Android

###:negative_squared_cross_mark: Ethernet adapter
The LED lights up on both ends of the cable, but I couldn’t find anywhere to configure it.
Only WIFI and bluetooth are available in the settings.

##Still untested, your help is welcome !

:grey_question: USB HUBS (very important, as they could help powering devices with higher power requirement)
:grey_question: VGA adapter
:grey_question: other NFC sticks
:grey_question: CD/DVD drive
:grey_question: full-size printer
:grey_question: scanner
:grey_question: camera remote control

This is a wiki, so feel free to experiment with your own gadgets, and share your results here !


Just tested a PCM2704-powered sound-card. (only the 3,5mm-Output, but I assume the others work too).
Works very well! The sound is automatically switched to the soundcard.
Even the buttons work. :slightly_smiling:

thanks refsifp
Is it kind of a small soundcard-stick ? Does it make a difference in audio quality with the internal sound ?
And buttons, what can they do ? volume control ? play/pause ?

@jaymanu: It’s a board with approx 5 cm x 5 cm. There are three buttons (vol +/-, mute), a 3,5 mm Jack, TOSLINK and S/PDIF.

I didn’t check the quality but it depends on the chip, not on the FP :slightly_smiling:

Do you mind, if I wikify your post, so everybody can add to your list? :slight_smile:

Great if you can wikify, that was my intent if I knew how to :slight_smile:

It’s now a wiki! (only the mods can currently wikify posts).

Will be keeping an extremely close eye on this topic, you guys are doing crucial research for possible backcover development!


For backcover, I think USB is already convenient, not sure I would buy a separate cover for each function.
One big problem is power, as you can’t plug an USB device and a charger at the same time.
What about some kind of easily detachable docking station, with power input and USB hub ?
If it doesn’t increase the cost too much, may also have hi-fi audio output, or handsfree speaker/mic, but that would be a bonus.

@retsifp, would you have time to test the PCM further ? How does sound quality compare with the regular output with headphones or an hifi amp ? Does it have inputs ? Can it be used for phone calls, or only “media” audio ?

2 new devices confirmed working : Smart card reader and MIDI instrument. See head post.

I’d like to add here that printers also work. Already some time ago I’ve written an app to print QR-Codes on POS printers (those used to print reciepts in shops). It is successfully tested with printers from Epson, Star and Custom, all of these manufacturers offer SDKs allowing to talk to their printers.

I’m quite sure that also regular printers and those small photo printers work. Which could be quite fun to print a photo directly from the phone via USB, now that I think of it…

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thanks @bfb and @Torsten_Romer !

@bfb : Could you give the reference of your thermal camera ? and the app you used ?
a screenshot would be great too :slightly_smiling:

@Torsten_Romer : could you update the wiki with the printers you are reporting to work, and apps that you used or even written ? I remember printing on Custom ticket printers years ago, in PalmOS and IrDA age :slight_smile:

Its the Seek Thermal Compact XR (XR : with focus, the same camera module without focus is called Seek Thermal Compact - those are the only models for android by seek ). The app used is the Seek Thermal app, the only app for this device.
I dont know what kind of references or further informations you need. As the device is rather unique, there is not much room for ambiguousness.

For further discussions and informations see FP2 compatible with Flir One?

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Thanks for this info !
Now it’s very clear.
Sorry if that was not as obvious for me as it is for you, i’m totally ignorant in the field of thermal cameras :slight_smile:

Sorry, I did not want to be rude. I just did not know what further references are needed.

Off topic: thermal cameras for smartphones are rather new, yet rare and it was a nice surprise that my model is actually compatible with FP2 (it even faces in the right direction). Good sign in terms of general compatibility of FP2 with common or not-so-common devices.

@jaymanu I finally added the tested USB printers, sorry for the delay!

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Sharing this easter USB keyboard illustration from @TobiasF

Mouse works (Logitech MX510) works. But not through a USB hub.

As stated here : FP2 audio quality

  • AudioQuest DragonFly : not working (external audio DAC)
  • HiFime DIY 9018D : working with 32ohm headset (not with 250ohm headset)

AudioQuest is to release soon an Android compatible DAC with low power consumption… I may have to wait.
HiFiMe DIY 9018D is reported as plug-and-play with Android 5.0 Lollipop (Nexus 6), but even with a 32ohm headset, I still have noises or cuts once every ~45s.

Thanks @siltaar for this update !
I updated the wiki accordingly, and reorganized it on the occasion.