The Trickster - USB Computer Prank

Introduction: The Trickster - USB Computer Prank

Plug The Trickster into your victim's computer, and it will randomly move their mouse while playing a game or using the desktop;
  1. Compatible with all operating systems
  2. Harmless fun: Acts as a second mouse, and goes away when you remove The Trickster from their computer

It's a fun little prank, here's a demo:

Even if you victim is computer literate he will suspect a virus or a remote control software in first place, please observe and stop him before he reformats the entire hard drive!

Another tip - if you really want to conceal the device , best way to do it is to solder a 4-pin header instead of the supplied USB plug, then plug the device directly into the USB socket on the motherboard inside the computer case. However be warned that this last step may result in the entire computer being thrown away out of the window!

Trickster is firmware updatable, so once you had fun with it you can re-purpose it as USB-to-Serial Converter, Propeller Programmer, USB IMU or one of many other application running on the UsbThumb platform.

Step 1: Make It: Tools

The Trickster is available pre-programmed right here.  If you pick it up that way, you'll just need a soldering iron and a bit of solder to add the included USB Jack and you're ready to go. 

Otherwise, to make The Trickster on a breadboard / protoboard, you'll need;

1 - Soldering Iron and solder. Leaded solder is easier to work with, and a 15-40 watt iron is just fine. A conical or chisel tip works well.

2 - Dikes. Diagonal cutters are used to trim the excess leads from components after soldering them down. 

3 - A PIC programmer.  The PICKIT3 works well, you can pick it up from mouser.

Step 2: Breadboard Version: Parts

First, I'll show you how to make a breadboard /Protoboard version - skip to step 5 if you've got a pre-programmed Trickster. 

Parts List:

1x PIC18F14K50 (digi-key)
1x 12 Mhz Crystal (digi-key)

2x 22pF Ceramic Capacitors
3x 47uF Electrolytic Capacitors (for power regulation)
1x 10k ohm Resistor

3.3v Power Regulator (mouser)

Male USB cable (Just about any spare cable will work)

Breadboard or Protoboard

Step 3: Breadboard Version: Programming

If you have the Pre-programmed version, you won't need to worry about this, but if you're building The Trickerster yourself, here's how you program the PIC18F14K50 (datasheet);

  1. You'll need a PIC programmer.  NOTE: Most programmers (like this one I got from Sparkfun) WILL NOT work with the 18F14K50.  You'll need to use a PICkit 2 or PICkit 3. There might be other programmers that will work with the 18F14K50, but be sure to verify they will before buying it.
  2. Download and install MPLAB from Microchip.  The MPLAB development environment only works on windows (the Trickster is compatible with all OS'es, though).
  3. Download the Trickster Hex file
  4. Connect the PIC18F14K50 to the PICkit, Microchip has made a helpful connection poster (pdf)
  5. Open up MPLAB, in the 'Programmer' dropdown, select PICkit 3 (or PICkit 2, if that's what you're using) and specify the target device.  It will give you a few warnings about programming the 18F14K50, just click 'ok'. 
  6. In MPLAB, click 'file -> import' and browse over to the Trickster hex file.  DO NOT USE 'FILE -> OPEN'.  If you do, It will appear that it has opened the hex, but it won't program the device.
Programming should only take 15-20 seconds.  Once it's done, it will say 'Program / Verify Complete'.  Now, let's build the rest of the circuit so we can test it out!

Step 4: Breadboard Version: Circuit

Below is the breadboarded circuit.  It omits the power - you'll need to provide a regulated 3.3v power supply (a pair of double AA's might work, but I haven't tried it). 
  • The crystal is 12MHz and connects to Pin 2 and Pin 3.  Also on Pin 2 and 3 are small ceramic caps, they should be around 22pf.
  • A 10k resistor should pull Pin 4 up (one end connected to 3.3v, the other end connected to Pin 4.
  • Pin 1 should be connected to a 3.3v power source
  • Pin 20 should be connected to ground

The header on the board should connect to your male USB cable.  Take your USB cable and cut off one end (the end that normally connects to the USB device).  There are 4 wires in the cable, here's how they connect to the circuit;
  • Vss = Ground - usually the black wire in your usb cable
  • D-, Pin 19 - usually the white wire in your usb cable
  • D+, Pin 18 - usually the green wire in your usb cable
  • Vusb, Pin 17 - usually the red wire in your usb cable
If you're unsure of your USB cable's wiring, use a multimeter to test continuity.  Here's how the USB jack is connected;

Here's the schematic, too;

(full size)

Step 5: Pre-Programmed Version: Assembly

If you have the Pre-Programmed version, everything's already setup except the USB jack.  It's included, just snap it on to the board and solder the pins, see the photo below.

The USB jack snaps on the board, sometimes it takes a little effort to push it in, but the bottom of the USB jack should be flush with the bottom of the board.  Once it's snapped in, just flip it over and solder the pins to the board and you're done!  The PIC is pre-programmed and ready to go.

Step 6: Next Steps

The Trickster will work reliably for thousands of pranks, but did you know you can re-program it? 

The Trickster firmware includes a USB Bootloader, so you can reprogram it without needing a PICKit - Starlino did a little walk through on updating it - it's pretty easy. 

Of course, you'll need to know how to program PIC's, but at least you won't need a PICkit to update the firmware.  If you program microcontrollers, he's created a Propeller Programmer firmware you can download and update.  Microchip also provides a variety of USB demos.

Have fun with The Trickster!

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    11 years ago on Introduction

    another way, is to put a small peice of tin foil in the optical hole, and it will randomly reflect therefor makeing it mouse around randomly....


    12 years ago on Step 6

    I'm sure this will prove a popular device beyond its initial frustration. I admit that mouse randomity would leave me extremely pissed! Normal drift of an optical mouse is enough to drive me up the wall.

    Be careful whom you prank--I wouldn't respond very favorably!

    Gadget Gangster
    Gadget Gangster

    Reply 13 years ago on Introduction

    T400.  Big and heavy, but feels solid.  Switchable graphics don't play well with linux, though.


    13 years ago on Introduction

    This could be much more frustrating if it was fitted internally to a spare USB header on the mainboard... You could ship the kit with an appropriate connector.


    Gadget Gangster
    Gadget Gangster

    Reply 13 years ago on Introduction

    You have a devious mind :)

    You can connect it internally if you do it on a breadboard, too!  I think the USB header is standard .1" spacing, too.