This week we had an important meeting with Chris Smith on Friday 10/8/21 for about 1 hour, as requested by professor Notash, regarding the project and our concerns/solutions. The meeting was very productive and Mr.Smith gave us very useful feedback and showed interest in the project.
Mr. Smith’s suggestions:
Conduct a proof of concept by placing transducers on both sides of a rigid sample. Play a simple sinusoidal signal through both transducers, with one out of phase, and measure the degree of cancellation. This will serve as a very basic proof of our device's function.
If the goal of our device is to cancel continuous/periodic noise, the system latency is perhaps less critical.
If it is intended to cancel irregular noise (like music) latency is critical.
When synchronizing clocks between IC's, Trace Length Matching is critical.
Achieving the proposed basic functionality of ANC is challenging enough to warrant omission of the comparator/switching function. Focus on getting it to work one-way before adding extra hardware/variables.
Rather than adding 2-way switching, perhaps "listen through" functionality can serve as an extension. This would only require the addition of a HF driver, secondary DSP program and touchscreen options.
Attempt to contact someone with a physics background to verify the feasibility of the device.
Given the advice taken from our meeting with Mr. Smith and our continued research we are confident in using the DSP (ADAU1466 eval) board with the USBi (to use with SigmaStudio) for the project.
Since Mr. Smith recommended that we conduct proof of concept we ordered the Dayton Audio Tactile Transducers to prove this concept as soon as possible.
Continued research was conducted on different types of microphones, more specifically Micro-Electro-Mechanical System (MEMS) omnidirectional microphones, rather than using the electret microphones.
John
Johns research indicates that using MEMS microphones shall be more efficient in comparison to the electret microphone for our design. The MEMS TDK ICS-40300 omnidirectional microphone has precision phase matching characteristics, excellent frequency range (6Hz - 20kHz), requires minimal power, and is of moderate cost.
The ADAU1466 Evalboard will allow for integration with a low-latency ADC/DAC
Programming of the EvalBoard requires the use of a USBi emulator:
Hunter
(Week 7)
This week we continued to contact Analog Devices forum in attempt to get feedback regarding concerns of latency in the design, as mentioned previously in our conversation with Mr. Smith. Hunter tried calling Analog Devices and was able to speak with someone but they said that all questions for their technicians are to be posted on the forum. No response was given to either of our teams posts at this time.
In the meantime, since the ANC project has been approved, Hunter is continuing his research on the exact details of the ANC project to catch up with his teammates progress and understanding, additional information still needs to be reviewed.
Points of focus are on the ADAU1466 DSP board, AB Push-Pull Amplifier, the implementation of using a feedforward ANC design, as well as the ANC duct test for proof of concept testing.
Updates to the website were also completed this week. There were some issue's in formatting some tables on the website so Hunter tried to contact a WiX Youtuber by the name of, Lorraine Lilley, (video below). Fortunately, she responded providing valuable feedback for creating tables in WiX.
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