Naughty Duck Will Be The End Of Secret Santa At Your Place Of Work

Aw, isn’t he cute? Looks are deceiving, because if you get him started, this duck says some vulgar things. [Gigavolt] found the little guy abandoned at the Goodwill store and decided it might have some hacking potential. Boy was he right. The stock toy can already sing a tune while flapping its beak and wings. After spending some time in [Gigavolt’s] lair, this duck is going to be on the naughty list. The best part is that this is going to end up in the hands of someone else thanks to a Secret Santa exchange.

The build article linked above is safe for you to read at work, but the video embedded after the break most certainly is not. [Gigavolt] got to work replacing the integrated circuit inside with his own PIC 16F628 microcontroller. He uses a new audio track, which is played back by a SOMO-14D audio player board. The two use different input voltage levels which is something of a bother, but it’s a standby power drain that has been vexing [Gigavolt] he rolled his own board using the DorkbotPDX order and can’t figure out why the current consumption is so high. Take a look at the cursing duck, then see if you can’t troubleshoot his electrical issues.

NSFW video: (language)


[via Build Lounge]

26 thoughts on “Naughty Duck Will Be The End Of Secret Santa At Your Place Of Work

  1. Freaking hilarious! Great job on the execution of this sweet Secret Santa gift. Hopefully the person you are giving it to has a good sense of humor ;-)

    As for your phantom current… I’m guessing it’s coming from the PIC, and going into the audio player through the CLK and DATA lines. You are driving those lines with 5.3V (6V battery – 0.7V diode drop), dropping the voltage through a diode (4.6V) but your audio player is running on 3.3V (a whole 1.3 volt difference). Your audio player likely has clamping diodes on it’s input, so your extra 1.3V is easily biasing them with a 3.3V supply on that chip. However, you have the 100 ohm resistors in there… so that should limit the current to (1.3V – 0.7V / 100) = 6mA. So if your idle state on the PIC I2C (?) bus is high, that’s only accounting for 13mA of current.

    You are also biasing your Motor outputs with 13mA of current on the base of those transistors… way overkill, although I have no idea what the transistors are, their gain, or the output current demand of the motors. Although, if they are on that’s another 26mA.

    I’m going to say your problem is the SOMO-14D sinking lots of extra current because you are over driving your CLK and DATA inputs. Fix that with resistor dividers that will drop the input voltage from 5.3V to 3.3V, without consuming a ton of current themselves. 2.2k and 3.3k would work pretty well. 5.3*3.3k/5.5k = 3.18V

    Let us know how it turns out ;-)

  2. Just on your consumption issue (hopefully I’m not missing something obvious), but why not power the pic from 3.3V (the spec sheet seems OK with it)? – that should sort that higher voltage appearing on the SOMO thing as well as any extra current flowing into it through the I/O.

    Also you could replace that linear regulator with an LDO to save power and those BJTs with FETs.

    Sometimes with PICs just making sure all your I/O is set right when going into sleep can make a huge difference.

  3. Awesome!
    The VCC problem struck my interest. I fetched your eagle design-data and had a closer look. even if the schematic has a couple ERC messages, it seems ok. BUT there are no diodes between the PIC and the SOMO, what also causes a bunch of forward annotation errors.

    Now looking at your pics i cannot tell if you put these diodes in before ordering the pcb, or if you modified that or if they’re simply missing.

    if they are missing, the whole situation does look a bit different: 5.3V – 3.3V = 2V, 2V / 100R = 20mA. (per signal in worst case)
    Still, reading the datasheet, a 100R Resistor is actually enough for use in a 5V system.

    Here’s my guess: In your schematic, you’re using 100-470uF for C3 and C4. Probably electrolytic caps. Are they mounted the right way round? Remember: on Tantalum caps (unlike the normal electrolytic caps) it’s the positive side, that’s marked.

  4. that PIC will run just fine on 3.3V, that should solve the problem of the different voltages and probably part of the high current as well, like Brett W. explained (I can’t reply for some reason)

    1. if you listen closely yoiu hear something like that:

      “Oh my god. That feels so good. Oh yeah. Slow down. Who’s your Daddy? Oh yeah. Play with my b@lls. Just roll them around. Oh my God. Uh oh. Slow down. Don’t move, I’ll go get you a towel.”

  5. I wanted to thank everyone for the comments. I needed 6volts to run the duck motors, but I never thought about using the 3.3 reg. to power both the PIC and SOMO-14d board. My power consumption problem is coming from the regulator itself. And it looks like I left out the diodes between the pic and somo on the board. I think I ran out of room.

    I should have used a voltage divider to drop the 5v to the 3.3 level.

    Thanks again! Your comments will help those that try to duplicate my project.

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