Download presentation
Presentation is loading. Please wait.
Published byLynn Margaret Manning Modified over 9 years ago
1
Monitoring Volume Level Application - End of Project Presentation Made by: Roi Abecasis Maxim Meltsin Supervisor: Boaz Mizrahi
2
Contents Table Previous Project Project goals Project milestones System demonstration
3
The Previous Project Multi-Sensors Personal Digital Assistant (PDA) By: Aviv Rosenberg & Ben-Ami Zilber
4
The Previous Project INPUTS: OUTPUTS: TOP LEVEL
5
Project Goals Automatic TV volume control Keeping TV volume on given level Detecting significant volume changes and acting accordingly Implementation of Universal TV Remote Controller (optional)
6
Project Milestones Part A: Microphone debugging microphone circuit Processing microphone samples Implementing an algorithm for AGC
7
Project Milestones Part B: Infra Red Learning existing IR Protocols (RC5, NEC,..) Detecting IR protocols frequencies Implementing functions for decoding IR messages Implementing functions for transmission
8
The algorithm Goal: -Finding reliable and stable method to measure volume level changes Problems: -Overcoming sensitivity for short but intense sounds -Avoiding ‘quiet’ samples -Typical TV Broadcasting volume is very inhomogeneous
9
The algorithm Solutions: 1.Measuring maximal value in time segment: new sample = max{sample(i)}, i=1,…,20 2. Averaging samples as follows: new avg = new sample + old avg 3. Throwing samples which are below certain value
10
The algorithm Implementation: 1.calculating stable value by sampling and averaging 2. Setting higher and lower thresholds values as app. 2% higher and lower then stable average value 3. An act is taken whenever a deviation from threshold values is detected
11
The algorithm Finding stable value Sample Start: Setting higher and lower thresholds New value < min => increasing volume New value > max => decreasing volume Otherwise do nothing
12
Two Main Infra Red Protocols NEC: RC5: f=38 kHz f=36 kHz
13
Implementation of different IR protocols issues Different Carry Frequencies Different ‘0’ and ‘1’ bit representation Different Start Sequence Toggle bit and repeat pulse Different bits number
14
System demonstration Universal Learning IR Remote Control Automatic Control of TV volume
15
Throughout work Presenting signal on screend decoding:
16
PDA Respond for 1KHz sinus wave
17
System demonstration National geographic channel: Channel 2: Channel 10:
18
System demonstration Universal Learning IR Remote Control Automatic Control of TV volume
19
Resource Usage CPU Usage: About 0.3% for average volume detecting About 1.1% in transmitting mode Typical total average usage = 0.3% Memory Usage: Less than 1Kbytes
20
Special Thanks to: Boaz Mizrahi – Supervisor Bruria Zohar – Lab technician
21
THE END
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.