Basic Binary Ultrasound Testing App Job Spec:

This app uses the mobile phone’s microphone to listen to a sound at high frequencies, which are being emitted by an existing machine, based on binary pulses. This application must: - Receive the binary signal which is being emitted - Display a decimal number as a result and refresh the result every 2 seconds - indicate when it refreshes - indicate: “no sound” if it does not hear anything - indicate “interference” if other sounds in the frequency band 20 – 22k are present but do not conform to the structure of the expected signal. The app MUST be designed on all of: - Blackberry OS6/7 - Android - iPhones GUI The design is not necessary, it can display basic text, black on white. Binary Sound Key Each “pulse” = 0.05s duration. A string will be up to 0.25seconds duration (consisting of up to 5 pulses), allowing a string to be repeated up to 4 times each second. Code is basic binary with 4 bits: Decimal Binary 0 0 1 1 2 10 3 11 4 100 5 101 6 110 7 111 8 1000 9 1001 The sound emitted from the machine will be: 20000Hz = 0 21000Hz = 1 21500Hz = gap 22000Hz = next string Example string: 21000Hz for 0.05 seconds 20000Hz for 0.05 seconds 20000Hz for 0.05 seconds 21000Hz for 0.05 seconds 21500Hz for 0.05 seconds 21000Hz for 0.05 seconds 20000Hz for 0.05 seconds 21000Hz for 0.05 seconds 22000Hz for 0.05 seconds this string is repeated forever App must decode this and display in decimal: 1 0 0 1 = 9 gap 1 0 1 = 5 next result to display = 95