Author Archives: stevey201

MEMO

EECE 380 (Group L2B1)

To: David Michelson, Associate Professor, UBC

From: Evan Huang, Student

Date: March 24^th, 2014

Subject: Weekly Review

Dr. Michelson,

During the week of Mar 17^th, our group attended the tutorials and attempted the exercises.  Last week we experienced some difficulty with the OrbComm e-mail system.  This week we successfully remediated the problem with the e-mail system and completed the exercise.  We also experienced a problem with our ADC exercise, where the analog input was not reading any of the signals.  This week we discovered the correct pin layout and quickly fixed the problem, successfully running the ADC demo with our voltage divider circuit.

This week’s tutorial, we focused on writing a script to forward and extract messages sent from the OrbComm satellite to our group’s G-mail account to our ece.ubc.ca e-mail account.  The message that is sent to our G-mail account is labelled with a specific subject header, and is therefore sorted and forwarded to an ece.ubc.ca account, where a script will export the message into an orb.txt file.  The text file will eventually be read and the data will be plotted into a GUI software (eg: Microsoft Excel, MatLab).

Overall, the progress of the project is slower than expected, yet time is quickly running out.  Our group has assigned two members to design the hardware and two members to compose the software, with one member managing parts and organizing the group as well as helping out where ever help is needed.  An order of electronic parts from DigiKey was sent to the T.A. this week to take advantage of the free shipping.  Our total budget for the course has come close to being exhausted from purchases for the OrbComm project.  We hope to have the parts as soon as possible, as time until our deadline is less than two weeks.

With Regards,

Evan Huang

MEMO

EECE 380 (Group L2B1)

To: David Michelson, Associate Professor, UBC

From: Evan Huang, Student

Date: February 9^th, 2014

Subject: Weekly Review

Dr. Michelson,

During the third week of the spectrum analyzer project we’ve made some progress in implementing and developing the hardware components of our circuit.  For the resolution bandwidth filter we’ve researched and built a crystal ladder filter with an expected1.5 kHz band pass, to cut noise and other signals out of our desired signal.  Thorough testing and analysis has shown that our crystal ladder filter has a band pass slightly less than 1.5 kHz, which is acceptable.  Our group is also implementing a low pass filter with a cutoff frequency of 1.5 kHz.  The low pass filter is fairly simple in design; however our group struggled to practically apply the circuit to cut out noise outside of the 1.5 kHz designed signal.   We’ve ordered several operational amplifiers of various frequencies above 10 MHz and are awaiting their arrival.  The op amps are to be used in building a precision peak detector to minimize the voltage drop between the input and output of the peak detector.

The two group members previously assigned to design the digital portion of our spectrum analyzer are continuing to familiarizing themselves with myDAQ and the LabVIEW software.  Specifics, such as input values and functions, are being considered for the LabVIEW program.  The members are implementing the ramp function and its relationship with the voltage-controlled oscillator (VCO) and the electronic mixer.  Its output would control the sweeping function of the spectrum analyzer.  One of the members expressed a concern with the insufficient amount of time to work with the myDAQ equipment.  Without being able to use the myDAQ outside of the labs we may not have enough time to properly troubleshoot the complete project in the future.

Our group members have come to build a rapport with one another.  We each contribute a certain necessary aspect to the group and the project, sharing both complications and successes.  Our goal for the following week is to complete the hardware design and begin troubleshooting with the given test specifications.  For the software, our goal is to fully develop the ramp and display functions, and begin troubleshooting with mock input signals.

With Regards,

Evan Huang