1

I am trying to put a custom message on a "sound box" in a stuffed animal. I asked this at the Reverse Engineering SE and they pointed me here. Here is a picture of the circuit board: board

The blue wires lead are connected to the speaker. The bottom holders are where two batteries go. I am thinking that those pads coming out of the chip that are not connected to anything might be used to put a new message on there. This board was in an "animal" and was not originally supposed to be modified so there is no microphone. Would this be possible? Any ideas on how I would do it?

NULL
  • 213
  • 3
  • 20
  • 3
    It might have a serial interface to upload data, but to figure that out you would need to have a scope or similar, and it is still possible that this is a one time process or using a custom protocol or is mask based rom anyways. You are better of getting some small micro with some flash and do a replacement board yourself. – PlasmaHH Jun 01 '15 at 14:46
  • The top connections with the fingers is probably your switch. As for anything else, it's doubtful anyone will have a good answer. All conjecture. – StainlessSteelRat Jun 01 '15 at 15:44
  • Its most probably a (factory) one time programmable (OTP) chip (under the black blob). Not meant to be updated. – JIm Dearden Jun 01 '15 at 16:13
  • 5
    Probably mask ROM rather than OTP to save a little cost. It may have more than one vocabulary selectable by pulling those unconnected pins high or low. A baby doll made the local paper one Christmas when (presumably thanks to a bad connection) it "swore like a trooper"... –  Jun 01 '15 at 17:23
  • I work in this industry. I agree with the others. My guess would be that there is a single custom IC under the encapsulation blob and the audio is encoded in mask ROM. OTP is possible, but not very likely, and even if it is OTP, you won't be able to reprogram it. Take PlasmaHH's advice and replace the whole thing. – user57037 Jun 01 '15 at 21:28
  • Ok...too bad. But, buying a new one is cheap I guess anyway. I could even strip it from one of those cards(the ones you do your own voice in). – NULL Jun 01 '15 at 21:33

1 Answers1

1

For future viewers, thanks to PlasmaHH and others I understand that most likely this audio is encoded in mask ROM. Or possibly it could be a one time programmable chip made in the factory. The easiest way to deal with this would be to buy a programmable one with some flash or strip it from a card that you can input your own audio into.

NULL
  • 213
  • 3
  • 20