Tag Archives: Hack A Day

This motorized skateboard is controlled by hand gestures

A Maker named Aditya has created a prototype skateboard controlled by simple hand gestures.

“I was just sitting in our Robotics Lab doing nothing. And then I had this idea to make an automatic skateboard, operated only by hand gestures,” Aditya explained in a recent blog post. “I [then] started gathering the parts. We had some very high torque BLDC motors just sitting there, with 75KG/CM of torque each making it 150KG/cm. [We] also had a uC board with [an Atmel] ATmega 16 on it, [as well as a] few long wires, limit switch and a bunch of connectors.”

As the Hack A Day crew notes, the sensor for hand gestures is currently connected by a control wire, although Aditya expects to transition to a wireless RF unit at some point in the future.

Aditya says he first assembled the chassis before kicking off the electronics side of the project, which included a breakout board for the ATmega 16 mounted on the corner of the deck. The above-mentioned board is apparent tasked with monitoring an accelerometer for steering as well as throttle.

“The accelerometer had been abused in a previous project so he had to add an extra switch to bolster his available inputs,” writes Hack A Day’s Mike Szczys. “We were glad to hear that he also included a kill switch, since putting the control of those motors in the hands of a damaged accelerometer is a bit sketchy.”

Additional information about Aditya’s hand-gesture controlled skateboard can be found here on his official blog here.

Printing a 3D Tardis-Transformer

Earlier this month, we gave props to a remarkably realistic DIY PIP-Boy (Personal Information Processor-Boy) made with a 3D printer. Today we’re taking a closer look at a Tardis Transformer which was designed using an open source RepRap 3D printer.

“I originally only had Soundwave in mind when I was designing this. So all the small details are based around his robot design. But I was catching heck for making the Tardis into a Decepticon so I repainted him and added a second head option to make him Vector Prime,” a Maker by the name of “Nonnef” explained in an Instructables post.

“I still think Soundwave would make an awesome Tardis, but anyone making this has their option of which to build. The print is still rough and needs cleaned up, but I keep changing the design faster than I keep up with actually printing him out. Going to keep it at a weekly print of what I currently have changed.”

As Hack A Day’s Brian Benchoff notes, be prepared for a very long print if you plan on having a go at the Tardis Transfomer, as the latest iteration of the model took approximately 30 hours with a .35 mm nozzle.

Nevertheless, the level of detail is impressive, as is the fact that 99% of the Tardis Transformer originated from a 3D printer – with only a pen spring and small screw scrounged elsewhere.

Additional information about the Tardis Transformer can be found here on Instructables, while details about Atmel-powered  RepRap 3D printers can be found here.

This mini computer is designed around Atmel’s ATtiny84

Recently, we discussed how a talented Maker by the name of Jack Eisenmann designed a multi-core homebrew computer using 16 ATMega328P microcontrollers. And today? A programmable computer based on Atmel’s ATtiny84 dubbed the DUO tiny.

“The DUO system interprets its own proprietary programming language to run all applications. This language is called DUO Tiny Programming Language, or DTPL,” Eisenmann explained.

“Software is stored in EEPROM (AT24C1024B-PU25) and loaded through a serial interface. The computer is equipped with 4 buttons and a 102 by 64 pixel LCD display (EA DOGS102W-6). [Meanwhile], a three-pin port is available on the DUO Tiny board, [which] may be used to inspect and modify the contents of EEPROM.”

As the Hack A Day crew notes, Eisenmann’s project began on a breadboard, but as he brought each part into being it transitioned to a strip-board prototype – and finally the fab-house version seen in the video above.

Additional information about the Atmel-powered DUO tiny can be found here.

This ATmega1284 is an 8-voice 32 kHz synthesizer

Atmel’s ATmega1284 is certainly a versatile microcontroller, but how many of us have thought of using the MCU to power an 8-voice 32 kHz synthesizer like Mike of Epromfoundry?

As the Hack A Day crew notes, we should particularly admire the cleanliness of the prototype shown in the video above, with each part given ample room on its own board – and interconnected by 10-pin IDC ribbon connectors.

So, how does it work? Well, to generate audio from the digital microcontroller, Mike built his own R2R digital to analog converter. A resistor ladder – created from 16 resistors – feeds a rail-to-rail amplifier. And although the sound is mono, playback is actually polyphonic due to Atmel’s stalwart ATmega1284.

“It is reading MIDI commands coming in from an external controller (we assume it’s the computer on which the hardware is sitting),” Hack A Day’s Mike Szczys explained.

“The chip’s 128 KB of Flash memory leave plenty of room to store samples, which are selected from a lookup table based on the MIDI data. If more than one sample is to be played the chip averages the data and sets the 8-bit output port accordingly.”

Additional information about the 8-voice 32 kHz synthesizer can be found here.

The ATmega32 WAV player

A Maker by the name of Vinod Stanur has created a WAV audio player powered by Atmel’s ATmega32 microcontroller (MCU). 

As the folks at Hack A Day explain, Stanur originally started development using a PIC microcontroller, although the component ultimately lacked sufficient SRAM to effectively act as a playback buffer.

“When he got his hands on an ATmega32 his mind turned back to the project and he saw it through to the end,” explained Hack A Day’s Mike Szczys. “He takes advantage of what he learned on several earlier builds. He’s using a TV remote as input, just like his Snake game did.”

In the most recent iteration of the project, storage is provided by an MMC card. In place of a FAT  (File Allocation Table) library, Stanur uses his own code to read the linked-list for sector addresses. The WAV header is subsequently parsed and the file processed accordingly.

“Playback uses two 512 byte buffers,” added Szczy. “One is feeding the output while the other is being populated from the memory card. When the output buffer is exhausted the two are swapped and the process continues.”

According to Stanur, the ATmega32 WAV player is capable of outputting both mono and stereo of maximum bitrate of 160KHz and 96KHz, respectively. Additional information about Stanur’s ATmega32 WAV player can be found here.