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problems with snap-o-lanterns

So I tried to make two snap-o-lanterns. One I wrecked trying to put the microcontroller into the socket (clumsy people should not try to make electronic kits). The second one seems to be fine despite some issues with the 6 pin DIL header (okay I actually put it in the wrong way and had to remove it).

The finished kit only has one LED light up now and then. That's it. No movement and nothing else happens. I have checked the soldering. It looks okay. Anyone have any ideas of what I can do? I'd really love to have one working snap-o-lantern after paying $60 (delivery and the kit) and spending hours on them.

The other thing I am wondering: if I bought the kit, do I have to program the microcontroller somehow? It doesn't say how in the assembly instructions.



  • Hi Glenn,
    You do not have to program the microcontroller at all-- it comes preprogrammed, and it *is* working correctly if you see one of the LEDs lighting up now and then.  (If you do have a reason to reprogram it, you'll need an AVR ISP programmer.)

    First, try to figure out what's wrong with the other LED.  There is *very* little that can go wrong here.  The LED is connected on one side to the pin of the chip and to the resistor, and on the other to ground.    Either, the LED is backwards, or there is a missing connection at one of those points. 

    Trace the wires and connections, and try to see where they go and match them to the circuit diagram.  At every connection, look to see if you can physically observe how the parts-- either wires, solder joints, or copper traces on the circuit board --are connected, to make sure that the diagram is actually implemented.  (And, if you have access to a multimeter, use that to verify connections between those points.)  

    If you can verify that all of the connections are correct, it could be that the LED is soldered in backwards.  You can check this by disconnecting one of its leads (desolder one of the two wires that touches the leads of the LED, and touch it one way or the other across the leads of the working LED.  That should tell you if the LED itself is good, and connected with the correct orientation.

    For the servo, follow the same basic procedure, however note that there are now three wires, not two, to trace.

    With regards to the other kit, with the damage to the socket, it's not beyond repair, so long as you haven't actually torn off any of the pins.  Strictly speaking, a socket is not needed, and you can wire the relevant pins-- there are only six of them that matter --directly to the circuit board with a little extra wire if needed.

  • I sorted out the mistake causing the issues I am having. The DIL header was in the wrong place. I guess you shouldn't try soldering stuff after a twelve hour workday especially when you are not that good at soldering in the first place. I didn't think I needed to program the microcontroller. I will keep that in mind about the socket.

  • I found a mistake. Even when I put the pin header where it belongs, it still didn't work. I am disappointed that after spending hours on this I am still debugging it. I am giving up. Two kits bought and delivered at high cost with no gain but hours of my spare time were lost. Besides my lousy soldering skills, the pins are so close together I can't solder accurately enough. I think I'm done.
  • I'm sorry to hear that you're still having trouble with it.  However, it is likely that the kits are both recoverable, should you decide to look into it again.
  • Thanks. Yeah. I'm done. I'm so tired I can't spend any more time than this (I work full time with three part time jobs) and I'm spending my spare time doing this.

    Maybe I'll try again next year.

    Thanks for the help.
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