Sound Blink03 Feb 2019
The sound blink is an incredible unique portable speaker. Check out Adhith’s project page on Hackster
Music and lights have always been a fascination to me. This project, which I named Sound Blink, is an effort to unite them. It’s a portable speaker with remarkable sound quality that has features which rivals commercial speakers. The LED light show along with the music is the main attraction of this project.
I was also very adamant on making the build with common materials so that even people without CAD could replicate. This also challenged my capabilities to find unconventional solutions and was an awesome experience.
The key design aspects are placement of electronics outside the enclosure which enables easy customizations and repair as well as a fully screw fixed assembly and curved wooden enclosure. Hardware features include 6 speaker drivers, a Wi-Fi controlled LED matrix with VU meter and multiple charging inputs. Furthermore, it has several user-friendly features like onboard music control soft buttons, charging level indicators and group function with AUX output. However, adding lot of elements to the project complicated the planning process to a great extent. For adding a new feature, a lot of critical dimensions should be changed to make room for it. This would in turn affects the other component arrangements that were planned earlier. Literally speaking, I was repeatedly customizing the entire project over and over again for a long time. Though it was daunting, eventually I came up with a detailed plan.
The need of a wooden circular enclosure compelled me to use the layer enclosure technique where each plywood cut-out were stacked on top of each other to form a single structure. Apart from being a time consuming process, it also had another drawback. The free hand cutting with the jig saw made all the sections a bit different in dimensions. This resulted in misalignments throughout the final enclosure. Though my belt sander helped a lot to smooth it down, still there were a lot of noticeable offsets throughout the enclosure. Since I already knew my limitations in wood cutting from the beginning, every attachments were designed to somehow mask the wood at every inch of the enclosure. As you can see, the finished speaker don’t expose wood at any portion. In this project, making things with low tolerance level and smooth surface finish were very tough to achieve. The practical solution was to mask the defect with a more flexible material. The use of fabric was a great option for it. I have extensively used it throughout the build. Also, black fabric makes glue stains and cloth edges less noticeable.
By including a VU meter (the circuit which lights up the LEDs to music) circuit, I was able to make the project more visually charming. The VU meter circuit which I designed had a dedicated op-amp based peak detector & output Darlington transistors for better sensitivity & reduced IC heating. The VU meter, WI-Fi LED driver and the specific wiring arrangement within the LED matrix enables a lot of custom light patterns and lighting effects. The switch box and wiring were another area of build which needed a lot of attention. To give you an idea, there were around 50 pin connections behind the switch box alone. All the wires coming from the switch box were properly labeled to avoid any confusion. Also special care was given to avoid any wrong connections to the circuits. Before powering the circuits, all connections from the switch box underwent a continuity test with my multi-meter to make things extra safe. Since this project dealt with various process like woodworking, electronics, and crafting, I was able to expand my knowledge in these areas. Working on this project was an incredible and rewarding experience and I’m thankful for the experience it has given.