[Isaac] sent in his mashup build of a LED cube combined with a graphic EQ meter. The build is fairly simple and from the video we can tell that his build would be a great installation in a dubstep venue. While it’s not the 9x9x9 cube possible with some judicious coding we think it’s a very fitting display for the intended purpose.
[Eli Skipp] wrote in to share a project she has been working on bit by bit, for over a year – an LED VU meter scarf. The project was originally going to be built using a custom PCB, but no matter how long she spent troubleshooting the piece, it just wouldn’t work right. She eventually broke down and purchased a VU meter kit, which worked out quite a bit better than the homebrew version.
The VU meter circuitry is tucked away inside the scarf as she shows in the video below. The LEDs are connected using conductive thread sourced from Lamé Lifesaver, which she says is far more durable than other threads she has tried. After originally testing the VU meter, she was unimpressed by the output of the LEDs, so she swapped them out for brighter ones, which look much better. It looks like it works quite well – we definitely dig the idea of a scarf with a built-in VU meter, even if it was partially built from a kit.
Continue reading to see [Eli] give a quick demonstration and a rundown of the scarf’s construction.
[Dillon] just finished his first project of the summer. It’s a volume units meter for his sound system and it has a few tricks up its sleeve.
He’s driving the rows of LEDs using an AN6884 LED driver chip. It has an integrated amplifier circuit which makes it the perfect part for building a VU display. He had a broken Linksys 5-port switch sitting around which he used as the enclosure for the project. It has just enough room to incorporate a speaker in case he wants to take the meter on the road with him. But when at home he can choose to use his stereo system instead with the flip of a switch. To ensure he’s making the most out of the 5-bit precision he’s included a voltage divider that can be adjusted with a potentiometer. We’ve embedded a video after the break which shows how well it works.
Looking for a bit more inspiration for your own VU meter project? Check out this RGB version.
[Simon Inns] turned out this VU meter with a 16 RGB LEDs. He’s using three 16-bit TLC5940NTG LED drivers for the project. They’re not cheap chips but they do a great job. If you were looking to save on parts [Simon] found there’s more than enough brightness and any loss due to multiplexing would not be a problem. The device connects to a computer via USB thanks to the PIC 18F2550 which he’s used in his past VU meter projects. One of the design choices he made was to use a switching power supply. The LM2576 (datasheet) has no problem sourcing 3A at 5V and in addition to two electrolytic capacitors which are commonly used with linear regulators, you just need to add a diode and an inductor.
The meter offers several different configurations which are set on the PC side of things. These include the colors that are used and if the entire bars is used as one meter or split into sections to display both audio channels. Check it out after the break.
WaitingForFriday’s [Simon Inns] is quite possibly the USB interface and PIC master. This week he let us know about his VU-meter repurposed as a computer performance monitor using a PIC18F2550 and his open source USB Generic HID communication class. With PWM the meter’s needles and RGB LED can be accurately set and even dampened for CPU usage, network usage, HDD utilization, and even memory usage. Oddly enough, in his software we didn’t find the ability to use the device as a VU-meter – go figure.
[Christian Doran] wanted some blinky goodness to go along with the tunes on his PSP. He built a VU meter circuit around a couple of LM324 op-amp chips and fit it into the UMD space on the back of the PSP. Using surface mount LEDs and some fine wire he lined up a string of indicator lights round the circle on the clear UMD cover. As you can see in the video after the break, the back of the case now pulses along with the music.
[Christian] notes that building the VU circuit around an LM3915 would have been much easier but he’s working with what he has on hand. Looks like he achieve the effect he was after. If you want to learn a bit more about how the op-amps work, take a look at the tutorial from our links post.
Hard drive speakers aren’t anything new, but they have yet to be done very professionally. Most hard drive speaker hacks are awesome, but aren’t meant to be a showpiece. [Oliver] took the opportunity to put together a set of 20GB drives and a custom-built acrylic case with a horizontal VU meter up front. The project is well-photographed and documented and can be recreated without the use of laser cutters or other expensive tools. The only thing it’s missing is an iPod dock!
Related: Giant bulb VU meter