Do you remember those first 8 bit computers and video game consoles? Do you remember how beautiful music they were able to play? This unusual device is a combination of modern technology and charm of 90’s. A seemingly simple plug, hiding a very small attiny10 microcontroller and two watch batteries inside – plays 2 minutes long Chiptune track, after plugged into the amplifier input.
Well you can see how much technology has moved forward, even 25 years ago to play that kind of tune you had to build a device with the size of today’s mini-computers. Now, a small 1,5 x 3mm package is all you need. The presented device is a clone of the original – Noiseplug – by dop3joe . Here you can watch the originalvideo, there is no project site at the moment. 1kB of flash memory and 32 bytes of RAM – this is all the author was needed to fit the “player” that generates sound at the PWM output (pin1), and save the whole melody. Originally, the code was created in C, but with the passage of time author was prescribing it to ASM, until there were left not a single line of C code.
The whole thing is so simple that there is no schematic. Very simple “printed” circuit board with dimensions of 5 x 8 mm was made by scratching-off-copper method, the caliper with sharp jaws is ideal for this task. It makes no sense to dabble in print and etching, scratched takes literally 5 minutes – and the effect can be seen on the pictures. Circuit begins to play a tune as soon as power is supplied, it uses the PWM output on the pin No.1. This pin can be directly connected to the input of the amplifier or computer sound card, because such devices have already capacitors on the inputs to compensate the constant voltage, which this circuit adds. Pin 2 is GND, pin 5 is VCC – that’s all.
The whole circuit is contained inside of a metal RCA plug, this neat construction can be seen in the pictures. Two “button” battery (3V in total) are located at the rear side of the plug. After tightening the connector housing, the positive electrode touches the VCC field on the board. Power supply from 1.8V to 5V, but the best is 2,5-3V. In my laptop 3V signal level was already on the verge of distortion, but the amp can handle this a lot better.
Attiny4 5, 9, 10 series chips uses TPI programming interface (tiny protocol interface). It will not be a problem because usbasp 2011-05-28 version officially supports this protocol, also USBTiny-MkII SLIM (clone of atmel’s MKII) will handle it as well. Just load the hex file from the attachment. The code has been created for the Attiny9, who from Attiny10 differs only with that, the first one does not have ADC – so they can be used interchangeably. If there is a need to compile the code, use the Atmel Studio 6, with use of included makefile.
(sorry for overdriven sound and shaky hands, it was recorded on the go)
POBIERZ – HEX file, ASM source file, license file