How is this playing music without uC/memory?

Hello,

Please see the attached pic. This device is playing pre-recorded 10/12 really small voice samples such as “Happy Birthday to you”, May God bless you" etc…It has a selection switch and volume control. When powered on it continuously repeats(in infinite loop) 1st voice sample until selection switch is pressed and released when it jumps to 2nd sample and starts playing in an infinite loop. Wondering how this is done without any IC/uC/memory…

See that big black blob in your last picture? That's the "brains". It could be a microcontroller, or custom logic. It was made specifically for this product so there is no need to put it in a plastic package with pins, like you can buy at distributors. It's just the raw silicon wafer, bonded to the board with small wires, then a big goop of black stuff is put on top to keep it in place.

-- Beat707: MIDI drum machine / sequencer / groove-box for Arduino

@ Above,

Thanks for the response. Yes, I did notice that black blob, however it's really small and thin. (less than 5mm x 5mm)..Hence I was not sure....What kind of IC would be able to perform such memory storage and b able to play without uC? And since its super cheap product(Made in Bharat(India)) I am not sure if it could be a custom logic....Thanks...

5mm x 5mm is plenty big. The actual silicon die is just a small part of the overall IC package:

The IC could very well be a microcontroller. Instead of having a handsome package with metal pins, it just has a blob.

-- The Flexible MIDI Shield: MIDI IN/OUT, stacking headers, your choice of I/O pins

however it's really small and thin.

So is the die at the centre of your AVR microcontroller - probably no more than 2 or 3 mm square and a fraction of a mm thick.

It would be cool if the plastic casing on an IC were transparent.

A tiny chip, held up by a bunch of tiny gold wires

sciguy: It would be cool if the plastic casing on an IC were transparent. A tiny chip, held up by a bunch of tiny gold wires

Yes - unfortunately, light can interfere with semiconductors, so a transparent chip is not too likely.

In fact all silicon diodes react to light just like a photodiode - photodiodes are optimized to let the light into the silicon.

Modern microprocessors probably could run in a transparent package though as they have 5 to 15 layers of metalization on top that should keep the light out!

Anyone else remember Steve Ciarcia’s DRAM (4116?) camera?

sciguy: It would be cool if the plastic casing on an IC were transparent.

A tiny chip, held up by a bunch of tiny gold wires

Which is exactly how certain types of image sensor chip are made. I used one, a TSL1401, in a 128-pixel line camera for the Arduino. My photo of the chip is here: http://www.flickr.com/photos/anachrocomputer/4896928437/.

KE7GKP: Brilliant! :-)

Thanks!

KE7GKP: Where did you get the sensor chip?

I bought it from Farnell, order code 124-2265, one-off price £6.66.

KE7GKP: Where did you get that lens extrusion piece?

It's a section of a magnifying ruler (W.H.Smiths) that I cut off with a hacksaw!

KE7GKP: What is the status of your project?

It works, and sends 128-pixel lines over the serial link at 115200 baud to a program on the host that I wrote in Processing to act as a display. I've been able to detect visible and infra-red light, and have done various tests on tracking IR beacons and detecting camera movement by optical flow. I think I could use a pair of IR LED beacons and make a distance sensor rather like the Wii "sensor bar". I'd like to make a much better lens, and I'd also like to combine the sensor with a red line laser module to make a laser harp.