https://microengineer.eu/2018/05/01/diy-night-clock-projector/ Zum Inhalt springen Primares Menu Advanced Electronic Projects * Startseite * Datenschutz * Impressum Suchen Suche nach: [ ] [Suche] Zum Inhalt springen Advanced Electronic Projects DIY Night Clock Projector Veroffentlicht am Mai 1, 2018Juli 31, 2021 von Thomas Pototschnig A Clock Projector can project the time to a ceiling in the night. DSC00244 There are lots of commercial alarm clocks with integrated clock projector on the market but I thought, it would be fun to build one myself. Moreover it was a good project for becoming accustomed to the process of 3d-designing cases which can be 3d printed and to learn about designing tolerances. The principle is easy - basically it works like a video beamer (or any other projecting clock^^). principle LCD and Calculations I choosed a small negative (background black) 64x32 LCD which has the dimensions of just 15mm x 12mm (active area 11.18mm x 5.58mm). lcd The goal was to build a complete projector with not more than 50mm x 50mm x 50mm (which I didn't managed ... But close to^^). A small LCD has the advantage that everything becomes smaller and cheaper - this influences heavily costs for optics because a smaller LCD needs smaller optics to project an low distorted image. Moreover a smaller LCD needs smaller focal length for a decent sized imaged on the ceiling. A good distance would be 2m from LCD to ceiling. The formula for image width depending from the focal length is defined as: Lens3.svg \frac{1}{f}=\frac{1}{S_1}+\frac{1}{S_2}\hspace{20mm}\frac{W_1}{W_2}=\ frac{S_1}{S_2} with: - S2 distance from lens to LCD and - S1 distance from lens to ceiling - W2 is the width of the LCD - W1 is the width of the projected image The formulas show that the smaller the focal length the larger the projected image will be. I decided to go for 25mm because there are cheap lenses which can be obtained for about $12 in china. For our values that would magnify the image by about x80 - 11.1mm LCD width would become 88.1cm image width on the ceiling in a distance of 2m. Light and Condensor Lens It was not really clear how strong a LED has to be in order to get a reasonable well readable picture in the night on the ceiling. To be sure - actually I wasn't really - I decided to use a high power LED with 1W and use a cheap chinese condensor lense to parallelize the light before it passes the LCD (this has do be done anyway but a condensor lens makes it possible to use more light because condensors are shaped in a way that allowes to get the lens as near to the LED as possible - so catching more light). 23131890_1213188468813683_2381276653004583966_n 23131607_1213188442147019_5008004252267984808_n The two pictures show the condensor-lense which is directly mounted to the PCB the resulting light spot on the ceiling. It is a really gread lens which is made for my LED - so it fits perfectly and parallelizes the light nicely. Electronics Construction Two PCBs were designed - one holding the LCD and the actual projecting board. Spectacle.J24673 Spectacle.J24643 The latter is equipped with 1W LED driver, STM32F103 Cortex ARM, a rotary encoder (for changing settings like brightness, standby-timer, time, ...), USB, IR (both not used yet). Mechanics Construction Originally, I aimed for 50mm x 50mm x 50mm but I only managed to get to 60mm x 60mm x 60mm Here an overview about all I designed: Spectacle.J23956 From left to right: Case with DIY projection lens (I skip this part - it worked but not really well), Sony E-Mount, C-Mount. In the middle the rest. LCD-Holder A custom LCD-holder was designed to perfectly mount the LCD on the right place on the PCB. 22780314_1206666822799181_4845087505472371951_n 22851997_1206666786132518_3949441219433421302_n Case - C-Mount Variant There are incredibly cheap chinase C-Mount lenses with a focal length of 25mm. They are sooo cheap that image quality is really really bad when using for fotography. 23380257_1223416981124165_4793755427854490814_n But surprisingly it works (almost) perfect for the Mini DIY Projector 23559568_1223771867755343_5931761190105667111_n The pillow-effect (optical distortion where the edges are not straight but bent outwards) is almost neglectable - resulting a much better image than I expected (after reading reviews to this lense) 23559460_1223772024421994_2585757183464992038_n Case - Sony E-Mount Variant Just for fun - and because I have a 3d printer which works reliably without much attention - I did a variant for Sony E-Mount. Spectacle.Tw9321 Here the projector with Walimex Pro 10mm 2.8 lens. 23380218_1219804668152063_8622113328646516671_n I have to admit - it isn't that bright in reality but it's still very readable although it is so large. DSC00244 The image has more than 2m in width! And distortions almost non-existent Downloads Followig GitHub-Repository contains: - Schematic - Layout - Bill of material - STM32 Cortex ARM Source - 3D-STL-Files - Images Link to GitHub Repository STL-Files on Thingiverse Ahnliche Beitrage Beitrags-Navigation Vorheriger BeitragIOTA PoW Hardware Accelerator FPGA for Raspberry Pi (und USB) Bloggen auf WordPress.com. * Abonnieren Abonniert + [wpcom-] Advanced Electronic Projects [ ] Anmelden + Du hast bereits ein WordPress.com-Konto? Melde dich jetzt an. * + [wpcom-] Advanced Electronic Projects + Anpassen + Abonnieren Abonniert + Registrieren + Anmelden + Kurzlink kopieren + Melde diesen Inhalt + Beitrag im Reader lesen + Abonnements verwalten + Diese Leiste einklappen Lade Kommentare ... Du muss angemeldet sein, um einen Kommentar zu veroffentlichen. [Schliessen und Akzeptieren] Datenschutz & Cookies: Diese Website verwendet Cookies. Wenn du die Website weiterhin nutzt, stimmst du der Verwendung von Cookies zu. 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