Any thrift store worth its salt will have a pile of the ever-popular “Billy Big Mouth Bass” motion activated signing fish… "ever-popular" as in “Was this really ever popular?” Apparently so, and apparently not anymore, given the number of them in second hand stores.
Here's what you'll need:
- 6V DC converter 300 mA, pos tip (or 4 C batteries)
- Billy Bigmouth Bass (or any similar annoying toy)
- 3-button mouse
- Wire cutter/stripper
- Soldering Iron & solder
- Elec tape or shrink tubing
- Screw drivers
Step 1: Hack Billy
Here we'll open up Billy, tear out unneeded guts, and ID the 3 pairs of motor wires we need:
- Remove back (6 screws on mine)
- Cut the battery wires (2 black,1 red on mine) and speaker wires (2 white on mine)
- Cut the power wires (Pinlk +, Black - on mine)
- ID the 3 pairs of motor wires coming out of Billy's body (see pics), verify what fish part they control (mouth, head, or tail) and the desired polarity (which direction the fish part will move) by connecting directly to the power wires (6V output on mine) or to your benchtop power supply. This will take some experimenting. Here's the color codes on mine:
Yellow- White+ : head
Red+ Black- : mouth
Orange + Brown - : tail
- Remove the circuit board, speaker, motion sensor, & button for other cool projects!
- Find a good hole to run the mouse cable through
Step 2: Hack the Mouse
Now we'll open up the mouse (mine is a Logitech M-M30) and rearrange some stuff:
- Cut the end connector cable off – decide how long you want your control wire, but leave enough on connector to use for something else. Strip the main sheath off, then strip and tin 4 of the small wires (remember the colors)
- Pull out the trackball & encoder wheels (more free project parts!)
- Open the mouse housing
- Cut the wires at harness end and remove the plug
- Choose the same 4 colors as you stripped on the other end, strip & tin, and cut any others short (won't use)
- Remove the control board, flip over, and ID the button solder points
- Remove all ICs & caps (weird stuff might happen if you don’t) – clip or desolder them
- Solder the correct wires to the correct button solder points (see pic) - for mine it was Red-left, Yellow-middle, Orange-right, and Black to common (the trace that connects all three buttons).
- reassemble mouse
Step 3: Put It All Together
By now you should have a modified mouse with a long tail, with 4 wires coming out the other end. These should now be soldered to the corresponding motor wires in Billy - for mine it was red to red, orange to orange, yellow to white, and black to pink (the +6V line). The other 3 motor wires (negative ends) all go to ground (Yellow-Black-Brown to Black in my case).
Put it all back together, tying a strain relief knot in the wire (see pic).
Now plug in the power (or put in the batteries) and test it out! try short bursts... the mouse switches are not rated to the current these motors will draw.
Last step is to label your mouse controller and try making your fish sing to a better song than "Take Me to the River" (see video)