FOUR CHANNEL ULTRASONIC RECEIVERTEAM CBRIAN MARKUS (TEAM LEAD)DANNY VISELMAN CHEN JIA

OVERVIEW• Design and create a Four Channel Ultrasonic Receiver,

capable of receiving signals between 30 kHz and 50 kHz.• Capable of receiving a chirp signal as well as a constant

frequency signal (Beacon).• Will work with Team B’s Ultrasonic Transmitter.

SYSTEM DESIGN

Level 0

Level 1

SYSTEM DESIGN (CONT.)

Level 2

TESTING/EVALUATION• Will use breadboards to build the system. Currently one channel is

built and we have been testing it.

• Initially used a function generator as the input signal to the system.

• Eventually we collaborated with Team B and used their transmitter to receive their beacon signal as well as their chirp signal and recorded the results.

• Once the board is milled we will build all four channels on the PCB and verify that each function simultaneously.

TESTING/EVALUATION (CONT.)

Figure 1 - Output of the mixer time domain and frequency domain, as well as the 33.5 kHz oscillator waveform

TESTING/EVALUATION (CONT.)

Figure 2 - Time and frequency output of receiver system (blue and pink, respectively) and transmitted signal from transmitter (yellow)

TESTING/EVALUATION (CONT.)

Figure 3 - Transmitted signal (yellow), received signal (pink) and beat frequency output (blue) at a distance of 53 cm

SCHEMATIC

SINGLE CHANNEL

BOARD LAYOUT

SOFTWARE PROCESS• Local Oscillator

• SPI Protocol• 16 bit binary number to calculate frequency

written to Arduino in Hexadecimal• Digital Amplifier

• 3 bit binary number to write gains of 0,1,2,4,8,16,32,64 Volts/Volt

• Synchronization with transmitter board.• Rising edge of TTL signal will start transmission

process and finish after a predetermined transmission time.

SIGNAL PROCESSING• Four different signal into the ADC• Use “fast” analog read (1us)• Use FFT libraries to analyze the four

frequencies • Extract Amplitude and Phase information

Q5: The project organization (WBS, schedule, and org chart) is specific and sufficiently detailed. The project is well planed.

Q7: Project risk has been identified and an good mitigation plan is in place.

PROJECT MILESTONES

• Signal Acquisition • Mixer/LO/Filter/Amplifier Hardware design• Over-voltage protection • Embedded system design (software) (halfway done)• Testing and evaluation

ORGANIZATION CHART

GANTT CHART

RISK MITIGATIONHigh risks:1. High volume of components2. Voltage/Current limiting3. Micro-solder required4. Vulnerable components involved5. Collaboration amongst team members and with the

transmitter team is crucial. 6. Time limit

SOLUTIONS:• Be careful, careful, careful, careful and careful• Using breadboard for testing and data collecting process before soldering the actual PCB• Schematic design• One time micro-solder board, no more budget and time for any more duplicates• Communicate with team B, regardless whether they want to talk to us or not• try to not loss too many micro parts

QUESTIONS ?