A blinged-out Pinewood Derby car #NeoPixels #Adafruit @Adafruit
Via the Adafruit forums, user beermat shows a rules-compliant Pinewood Derby car that is decorated with lights, sound and video.
Presenting “The Light Fantastic v2”, a rules-compliant Pinewood Derby car that is decorated not with paint and stickers, but lights, sound and video, with (almost) all products obtained from Adafruit! Under the hood is a Teensy 3.6, powering 47 NeoPixel lights (3 Sticks, 1 Jewel, 1 Ring and 4x individual), one small LED back-light underneath, an Adafruit 1.54” 240×240 TFT display (removed from the breakout), a small “SugarCube” speaker, PAM8302 amplifier and a LSM9DS0 9DOF sensor.
User input comes via a small digital joystick and two micro push buttons, as well as tilt sensing. Various animations are programmed in to show on the display and/or NeoPixels, as well as the ability to play video at ~37 fps full screen (1:1) and ~50 fps letter-boxed (3:2). A custom built menu system adds additional goodies, such as a photo viewer, music player, video player, settings, calibration of 9DOF sensor, and access to games like Pacman and Flappy Birdz! A 400mAh LIPO powers this all for around 3 hours, but it can run off tethered USB power too.
The Teensy 3.6 has 256k of RAM, enabling the use of an in-memory buffer for fast screen updates, the heart of this project. Full screen 240×240 at 16 bits of colour requires ~115K of RAM for the buffer and using SPI with a bus speed of 90 Mhz (CPU clock speed 180 Mhz), the transfer to the display takes ~22 ms. Reading a full video frame from the Teensy SD card adds a further 6 or 7 ms, so playing video converted to a 23.98 fps rate is easily achievable! Semi-intelligent reduced data transfer allows for a 240×160 video to play at ~50 fps. This can be unnecessarily further improved by overclocking the Teensy up to 240Mhz/120Mhz, but the battery does not like this!
The electronics (display, lights, battery, Teensy, 9DOF sensor, switches, speaker, amp, joystick, wiring) weigh ~1.4 oz, so easily light enough to put inside a Pinewood Derby car and within the “legal” weight limit of 5oz. The wooden chassis, wheels and nails weigh ~1.3 oz, so additional tungsten weights totaling 2.2 oz were added. Track speed of car yet to be determined, but it rail rides, runs on 3 wheels and is weighted at the rear as much as possible, given the constraints of the electronics placement.
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.