{"product_id":"snowflake","title":"Snowflake: a project by Lucky Resistor","description":"\u003cp\u003eA set of five shimmering snowflakes that talk to each other to synchronise their nineteen cool white LEDs that sparkle and fade to create beautiful wintery effects. \u003c\/p\u003e\n\u003cp\u003eThe snowflakes come pre-assembled on a gorgeous, festive-looking PCB panel. Each snowflake is pre-programmed, so all you have to do is pop them out, connect them together with the cables, and plug in power to bring them to life.\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/learn.pimoroni.com\/tutorial\/sandyj\/assembling-snowflake\"\u003eCheck out our tutorial on how to get started with your Snowflakes.\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003eThey are programmed with eleven patterns; Ice Sparkle, Sky With Stars, Waves, Circles, Rain, Shift, Rotation, Diagonal, Flash, Particle, and Flicker. You can change between patterns and turn the snowflakes on and off using the button the power supply board. Check out \u003ca href=\"https:\/\/youtu.be\/w-GqsQLUh2w\"\u003ethis video\u003c\/a\u003e to see the patterns.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003c\/strong\u003eThis project was originally designed by \u003ca href=\"https:\/\/luckyresistor.me\/\" target=\"_blank\"\u003eLucky Resistor\u003c\/a\u003e as an assemble-yourself kit which took a lot of time and a very steady hand to complete! We've worked with them to make the kit accessible by pre-assembling the surface mount components and pre-programming the microcontrollers.\u003c\/p\u003e\n\u003ch2\u003eContents\u003c\/h2\u003e\n\u003cp\u003eThe kit comes in a beautiful gift box with the contents wrapped in black tissue paper and an introduction sheet to get you started. Perfect as a present!\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e5x pre-assembled and pre-programmed snowflake PCBs\u003c\/li\u003e\n\u003cli\u003e1x pre-assembled micro-B USB power supply PCB\u003c\/li\u003e\n\u003cli\u003e1x power supply acrylic cover\/switch with fixings\u003c\/li\u003e\n\u003cli\u003e4x 20cm flat flex cables (FFC)\u003c\/li\u003e\n\u003cli\u003e1x 100cm flat flex cable\u003c\/li\u003e\n\u003cli\u003e1x introduction sheet\u003c\/li\u003e\n\u003cli\u003ePanel dimensions: 214x153x3.15mm\u003c\/li\u003e\n\u003cli\u003eSnowflake dimensions: 79.5x79.5x3.15mm\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eNote\u003c\/strong\u003e that a micro-USB power supply \u003cem\u003eis not\u003c\/em\u003e included, but you can \u003ca href=\"\/en-eu\/products\/raspberry-pi-universal-power-supply\"\u003epick one up here\u003c\/a\u003e.\u003c\/p\u003e\n\u003cp\u003eIf you want to experiment with reprogramming your snowflakes, you can solder a 5-pin 0.1\" vertical female SMT connector to the landing on the underside of the snowflakes. Here are a couple of options: from \u003ca href=\"https:\/\/www.toby.co.uk\/board-to-board-pcb-connectors\/254mm-sockets\/b27a-valcon-254mm-single-row-surface-mount-staggered-socket-strip-5mm-profile\/\"\u003eToby\u003c\/a\u003e, and from \u003ca href=\"https:\/\/www.digikey.co.uk\/product-detail\/en\/sullins-connector-solutions\/NPPC051KFXC-RC\/S5636-ND\/776095\"\u003eDigikey\u003c\/a\u003e.\u003cbr\u003e\u003c\/p\u003e\n\u003ch2\u003eFeatures\u003c\/h2\u003e\n\u003cp\u003eEach snowflake has: an \u003cstrong\u003eARM Cortex M0+\u003c\/strong\u003e microcontroller that runs the firmware to control patterns on the LEDs, \u003cstrong\u003enineteen cool white 0402 LEDs\u003c\/strong\u003e, input and output connectors (for the FFC cables), a landing for a debug\/programming header, and power regulator.\u003c\/p\u003e\n\u003cp\u003eThe snowflakes can communicate via a \u003cstrong\u003esingle bi-directional data line\u003c\/strong\u003e. During power up they determine their order in the chain so that effects can transition between them seamlessly. The first snowflake—the “master”—decides which effects will be displayed and \u003cstrong\u003esynchronises the other boards in the chain\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp\u003eThe key to the snow-like shimmering effect are the \u003cstrong\u003etiny 0402 LEDs \u003c\/strong\u003e(check the photo with the pencil tip to see just how small they are). The small but bright, point-like light source \u003cstrong\u003ecreates diffraction spikes\u003c\/strong\u003e in your eyes. It's the same effect you experience if you look at snow in bright sunlight.\u003c\/p\u003e\n\u003cp\u003eIt was important to ensure that the \u003cstrong\u003eLEDs' brightness changes linearly,\u003c\/strong\u003e since both LEDs and your eyes are non-linear in that respect. This was solved using a \u003cstrong\u003ecustom PWM control method\u003c\/strong\u003e. It is optimised to display a wide range of brightness levels and to work well at very low brightnesses (a common weakness of PWM brightness control). \u003c\/p\u003e\n\u003cp\u003eThe \u003cstrong\u003ekit includes flat flex cables to connect the snowflakes\u003c\/strong\u003e and power supply together easily. Alternatively, if you want to minimise the visibility of the cables, you can connect them by soldering super-thin enamelled wire using the exposed pads on the back of each snowflake.\u003c\/p\u003e\n\u003cp\u003eThe entire project (including the firmware, schematics, bill of materials, and PCB layout) is \u003cstrong\u003eopen source under GPLv3\u003c\/strong\u003e. You can find all of the files in the \u003ca href=\"https:\/\/github.com\/LuckyResistor\/SnowFlakeProject\" target=\"_blank\"\u003eGitHub repository\u003c\/a\u003e.\u003c\/p\u003e\n\u003cblockquote\u003e\n\u003cp\u003eOver the past few years I have designed a new decoration for my home each winter. This snowflake decoration started as one of these projects.\u003c\/p\u003e\n\u003cp\u003eI asked a graphic designer friend, \u003cstrong\u003eFrancesco Mazzola\u003c\/strong\u003e (\u003ca href=\"https:\/\/www.mdmbunny.com\" target=\"_blank\"\u003ehttps:\/\/mdmbunny.com\u003c\/a\u003e), to design the outline and detailing which I then converted into functional PCBs.\u003c\/p\u003e\n\u003cp\u003eInitially, I produced a small number of kits which were offered to members of the \u003cstrong\u003eBoldport Club\u003c\/strong\u003e (\u003ca href=\"https:\/\/boldport.com\/\" target=\"_blank\"\u003ehttps:\/\/boldport.com\/\u003c\/a\u003e). Due to the low volume, these kits were expensive to produce and the customer had to hand-solder all of the components—including the ninety-five individual 0402 LEDs—ouch!\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003ePimoroni\u003c\/strong\u003e found out about the project and got in touch to see if they could create a more accessible version as a kit with all of the surface mount components pre-assembled. I said yes! :-)\u003c\/p\u003e\n\u003cp\u003eThey reached out to \u003cstrong\u003eMicrochip\u003c\/strong\u003e (\u003ca href=\"https:\/\/www.microchip.com\" target=\"_blank\"\u003ehttps:\/\/microchip.com\u003c\/a\u003e) to see if they could support the project to help reduce the cost. As the kit includes five ATSAMD20E16 they made up a large part of the overall cost!\u003c\/p\u003e\n\u003cp\u003eI hope you enjoy this project as much as I enjoyed designing it!\u003c\/p\u003e\n\u003cp\u003e- Lucky Resistor\u003c\/p\u003e\n\u003c\/blockquote\u003e","brand":"Pimoroni","offers":[{"title":"Default Title","offer_id":31146259578963,"sku":"PIM481","price":31.95,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0174\/1800\/products\/snowflake-2_d0586cd6-ba13-4be8-aba9-5340370b0c21.jpg?v=1573647023","url":"https:\/\/shop.pimoroni.com\/en-eu\/products\/snowflake","provider":"Pimoroni Ltd","version":"1.0","type":"link"}