FOUR CHANNEL ULTRASONIC RECEIVER

TEAM 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 MITIGATION

High risks:

1. High volume of components

2. Voltage/Current limiting

3. Micro-solder required

4. Vulnerable components involved

5. 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 ?