[Jacques] thought his doorbell was too loud, so of course the first thing that came to mind was replacing the electronics and playing a WAV file of his choosing every time someone came knocking. What he ended up with is a very neat circuit: he used a six-pin microcontroller with 64 bytes of RAM to play an audio file. (French, Google translation)
The microcontroller in question is a PIC10F322. one of the tiniest PICs around with enough Flash for 512 instructions, 64 bytes of RAM, and a whole bunch of other features that shouldn’t fit into a package as small as a mote of dust. Without the space to store audio data on the microcontroller, [Jacques] turned to a 64 kilobyte I2C EEPROM. The PIC communicates with the EEPROM with just two pins, allowing it to read the audio data and spit it out again via PWM to an amplifier. The code required for this feat is only 253 instructions and uses just a few bytes of RAM; an impressive display of what a very small microcontroller can do.
While the Raspberry Pi has very good support for an I2C bus, a lot of very cool chips – including the in system programmer for just about every ATtiny and ATmega microcontroller – use an SPI bus. [Louis] sent in a tutorial for getting hardware SPI on his Raspi, and even though it’s rather limited right now, it’s a step in the right direction.
Previously, [Brian Hensley] put up a tutorial for using the Linux SPI drivers with the Raspi. [Louis] wanted to play with SPI in Python, so he added a C extension to the spidev.c file (available here) that allows him to open an SPI connection, initialize, transfer, and close the connection.
After connecting an Arduino to the MOSI, MISO and SCK pins of his Arduino, [Louis] was able to transfer data from his Raspi over an SPI bus. It should be noted that a level shifter would be a really good idea here, but this is an excellent project if anyone would ever want to port AVRDude to Python.
So this is what happens when a fan of The Rock-afire Explosion grows up. Meet Compressorhead, a musical trio of hydraulic and pneumatic musical mastery.
Compressorhead is a lean band, consisting of only three members. Stickboy, the drummer, is a four-armed beast reminiscent of [General Grievous] that plays a 14-piece Pearl kit with a double bass. His listed influences include [Danny Carey] and the original MPC60.
Fingers is the guitarist and a wonder of mechanical linkages consisting of 78 hydraulically actuated fingers. Influences include [Yngwie Malmsteen], but with more fingers and less of an ego, we expect Fingers to be an even better guitarist than his idol.
Bringing in the low-end is Bones, the robotic tread-mounted bassist for Compressorhead. Like Fingers, he plays an unmodified instrument. He’s also the newest member of the band, completed in 2012.
If you’d like to check out Compressorhead in person, they seem to be touring Australia right now. If you’d like to schedule them, their rider lists a requirement of 65 Amp, 3 phase power, 3 liters each of hydraulic fluid and motor oil, and suspiciously no requirement for removing all the brown M&Ms from a package. Be sure to check out the videos of the band in action on their media site.
Thanks [BadWolf] for sending this one in.