All of the Lights

Visualization of Bluetooth transmitted vinyl signal

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Inspiration

Eli and I realized how much Sid loved vinyl and wanted to incorporate it into our final project. With this in mind we created All of the Lights a system that transmit a signal from a record player over Bluetooth, and then visualizes the signal by passing it through high and low pass filters.

Sub components

Hardware We used a Technics direct drive record player, and a phono pre-amp. With these two devices we are able to take acquire a "line-in" ready signal. This signal can either be hardwired or sent with Bluetooth to high and low pass filters. These filters each got the same signal and separated the high and low frequencies which were then displayed on a two separate LED strips.

Software With the introduction of the Bluetooth, Arduino code had to be written. We found that music is typically transmitted at 703,000 bits per second so we set the BTSerial.Begin to 706000. This allowed us to attempt to reach the speed that the record player was gather information.

First Deadline

For the first deadline we want to secure a signal from the record player, and visualize with our filter.

Second Deadline

For the second deadline we want to transit the signal with Bluetooth.

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Updates

posted an update —

Our project intended to adapt the Pretty Lights lab, but add the use of bluetooth and a record player. We got this idea thinking back to the first class when Professor Sid used a record player to demonstrate an oscilloscope. Me and my partner are both interested in vinyl, so we decided to incorporate this into our program. After the Pretty Lights lab, we thought that a good final project would be to recreate this lab, but instead of using a standard line-in signal, we would instead use the signal from a record player, that would be transmitted to the circuit using bluetooth. For the first demo day, we successfully recreated the Pretty Lights lab with a direct signal from the record player. After some tinkering, we were able to get fairly responsive lights. An issue that we faced at this step was making sure that the signal coming out of the record player was strong enough to be seen in the lights. Since the raw signal out of a record player is very quiet, we had to incorporate the use of a pre-amplifier. This gave us a signal that was about as loud as a standard line-in. After we got this, the lights worked as well with the record player as they did initially. The final project was comprised of a few subcomponents. First, the signal is generated in the record player. It then gets initial amplification in the pre-amp. From the pre amp, the signal is sent directly into a bluetooth chip connected to an arduino. A separate arduino was connected to a paired bluetooth chip. This arduino output the signal from the bluetooth chip into the beginning of the pretty lights circuit. This circuit was comprised of a high/low filter, which separated the signal into bass and treble components. Each of these sub-circuits fed into individual LED strips. This could be turned into a product by housing all of the filter and LED circuitry in a fancy box. This box would be able to pulse with the music, without direct wires from the source. During the construction of this project, we ran into a few issues. We realize that that the signal that the record player produces is much too fast for standard bluetooth/arduino communication. This could be fixed by fine tuning the source signal to be at a sampling rate that the bluetooth can communicate, or by writing more advanced code. A second issue we faced was the loss of strength of the signal. As the signal was processed and transmitted, it lost a lot of its power. This made the lights flicker very faintly, instead of the noticeable pulses we had observed before adding bluetooth. This could be fixed by adding an additional amplifier, or by simplifying the circuitry, such that less power was lost during the processing.

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