Computer Combination Lock

Eric Betts created a computer combination lock.

The lock uses the Teensy, rotary encoder, circular led bar graph, and the encoder library.  You twist the knob to the correct position as indicated by the LEDs, push down on the knob to set that value, and on the 3rd value the sequence will be checked against the first 3 bytes of EEPROM. If the combination is correct, “Secret Word” is sent as keyboard input.

The code for the project is available on GitHub.

Dodecahedron with LEDs and Infinity Mirrors

Neil Merchant has made a pretty awesome dodecahedron with LEDs and infinity effect.

The dodecahedron, named Carl, uses a Teensy 3.6, OctoWS2811 adapter, SK6812 RGB LEDs, and 1-way mirrors to make the magic happen.

Neil is planning to take Carl to different festivals.  It will be making an appearance at Electric Forest, Lost Lands, and maybe Ever After Fest.

You can follow the the story of Carl’s development on this Twitter thread.

Squareinator – SN76489 Monosynth

Alex Davis made Squareinator – a SN76489 Monosynth.

After being handed an old package of the SN76489 sound chip, Alex wondered if could be used as a synthesizer.  After a bit of research he was inspired to make the Squareinator.

Squareinator drives a SN76489 vintage soundchip as a monophonic
synthesizer, using all three squarewaves plus pseudo-random noise to
deliver a fat synth sound. A multi-mode 12 db/oct VCF adds additional
character and is playable at full oscillation. All synth functions are
exposed as MIDI CCs. The ATMEGA32U4 in the Teensy 2.0 allows us to use
the high-speed timer PLL to provide the 2 mHz clock required by the
SN76489 with no extra parts.

You can find the code for the project as well as a schematic on GitHub.

RF Power Meter Using AD8307 Log Amplifier

Loftur Jónasson built an RF Power Meter.



Lofture says that it was simple to build.  It uses a Teensy ++ to sample from an AD8307 logarithmic amplifier from Analog Devices, 200 times per second. A Rotary Encoder with a built in Pushbutton is used to navigate the various displays and to access a settings/configuration menu..

The project web page has a detailed write up and includes the code for the project.