I/O Expander for LED Arcade Buttons

Teensy creator Paul Stoffregen has shared a new project on OSH Park:

I/O Expander for LED Arcade Buttons

The Monolith Synth Project needed to use a large number of these LED lit arcade buttons.

Dimming of the LEDs was required. Initially I considered using this Adafruit 16 Channel PWM board. But the LEDs in these buttons have integrated resistors which require 12 volts, so 16 transistor circuits and another board for reading the switches would have also been needed.

It uses the same PCA9685 chip for 12 bit PWM control on every LED, with mosfet drivers to handle 12V outputs, and also a MCP23017 chip to read the buttons. Every button has a discrete 1K pullup resistor (rather than using the higher impedance on-chip pullups) to help with use in the same cable bundles cross coupling to 12V PWM signals.

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Monolith Synth

Four of these boards where used in the Monolith Synth project:

monolith_before_mf

The project is featured in this Tested video:

I/O Expander for LED Arcade Buttons

Trixel Interactive LED Kit

Arkadi designed this interactive LED kit:

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Trixel LED

Create your own interactive Light elements by soldering basic shapes, such as triangle, square, pentagon and hexagon to create an interactive LED sculpture.

Here’s a video of the Trixel LED boards in action:

The design files are available on GitHub:

arkadiraf/Trixel-LED

 

Arkadi_Raf has shared the boards on OSH Park:

Pentagon LED

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Square LED

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Triangle LED

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Trixel Interactive LED Kit

LED Matrix Generator for EAGLE

Ted Yapo is designing a display for his  LED Oscilloscope Mk. II and decided to automate the process:

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16×32 Display Design

I painstakingly drew the schematic for 512 LEDs in this display, then endured the drudgery of laying out the board. The whole process took about 45 seconds. Yes, I wrote a few Eagle User Language Programs (ULPs) (elapsed time after the scripts were written and debugged). The previous time I wrote one was last century to lay out a circular LED clock face. I figured it was about time I regained those skills.

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The EAGLE ULPs are on GitHub:

led-matrix-generator

 Eagle scripts for LED matrix display generation

LED Matrix Generator for EAGLE

Brake Lamp Flasher for Motorcycle

Bryan Cockfield of Hackaday writes:

Brake Light Blinker Does It with Three Fives

Sometimes you use a Raspberry Pi when you really could have gotten by with an Arudino. Sometimes you use an Arduino when maybe an ATtiny45 would have been better. And sometimes, like [Bill]’s motorcycle tail light project, you use exactly the right tool for the job: a 555 timer.

boardsMore details on William F. Dudley’s project page:

Brake Lamp Flasher for Motorcycle

The 555 is a clever chip; not only will it supply the oscillator for the flashing effect, it has a reset pin that can be used to force the output to a known state (low) when (other circuitry tells it that) it’s time to stop flashing. Thus the brake light will be steady “on” after a few flashes every time the brake is applied.

brake_blinker_1_schem

The 555 is happy to run directly off the nominal 12 volt vehicle electrical system, so no voltage regulator is needed. The 555 is almost immune to electrical system noise, so no worries about your Arduino code going off into the weeds if there’s a spike from the electrical system.

 

Brake Lamp Flasher for Motorcycle

Tilt activated LED watch

askoog89 saw a major flaw with many LED watches – you have to press a button to see the time:

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A Watch

I tried fix that problem by using a tilt switch to active the LED showing the time when tilt your arm to look at the watch

The watch uses the low power MSP430G2211 MCU from Texas instruments to control the LED and mesure the time with the help of a 32kHz watch cristal. The MCU sleeps most of the time only waking up ones a second to count up the time and check if the tilt switch is active.  To show the time the watch uses 12 charlieplexed orange LEDs.

Tilt activated LED watch

Electro Pet plays Santa

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Electro_pet by Facelesstech

I got inspiration for this project from the petduino. The petduino is a great project to get kids into coding and electronics. I thought I would have a go and see if I could add some more features to it. Also my daughter was really interested in the 8×8 led matrix

Hardware walkthrough video:

Video of Santa hat and breathalyzer hat for the Electro Pet:

Design files and source code are available on GitHub:

images11 facelessloser/electro_pet

 

facelessloser has shared boards on OSH Park:

electro_pet

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santa_hat_rev_b

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Electro Pet plays Santa

reDOT: Tiny 5×7 LED matrix

al1 created this remake of the old Texas Instruments TIL305 display with tiny surface mount LEDs:

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reDOT

TIL311 had a alphanumerical brother the TIL305. This was a 5×7 LED matrix in the same form factor

Here is a video of reDOT in action:

ALKR has shared the board on OSH Park:

reDOT

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reDOT: Tiny 5×7 LED matrix