Monthly Archives: March 2014

MEMORANDUM

Date: March 30th, 2014

To: David Michelson, Associate Professor, UBC

CC: yinh@ece.ubc.ca

From: EECE 380 Group L2B1

Subject: Weekly Review

Dear Dr. Michelson,

The purpose of this memo is to inform the course staff of EECE 380 about our team’s progress during this past week as well as any difficulties we encountered.

Our group continued with our design process, working on each component of the project. Parts ordered from Digikey had arrived and we were able to test and begin implementing each components of our design. Temperature sensor was easy to be set up, which only required a load resistor for calibration. An IR emitter and a photodiode were used to transmit and receive infrared signal so that we can measure the RPM of the windmill. One problem we faced was the effective distance is too short so have to make sure they are working the range next week. We intended to power all of our sensors and actuation circuit a solar cell we ordered from Digkey. It could output a steady voltage about 6V but the current obtained was too small, which was around 60 micro-amps. Therefore we might have to go to an electronics store to purchase another more powerful solar cell.

Next week we will finish combining the main functions of Q4000 into one program. Also, we will finish implementing and integrating all the hardware components. We hope to have the two jobs done as soon as possible, as time until our deadline is less than a week and we need time for troubleshooting.

With Regards,

Chun Yeung Chow

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

Memorandum

To: David Michelson, Associate Professor, UBC

From: Anupam Abhayakumar, Student

Date: March 16^th, 2014

Subject: Weekly Review

Dear Mr. Michelson,

This week we continued with our Orbcomm project and we are pleased to find that our hello world program works fine. However the email demo did not work as we could not get the email to send more than once. We believe it to be due to the satellites being out of range in that moment of time.  Secondly, we constructed a voltage divider for our ADC circuit using 357k Ohms and 866 k Ohms resistors. The unmodified ADC demo works, but there were some issues with modifying the program to read channel 0 of the analog input. We have to yet to investigate into the third tutorial in the upcoming lab days.

With Regards,

Anupam Abhayakumar

Date: March 10^th, 2014

To: David Michelson, Associate Professor, UBC

CC: yinh@ece.ubc.ca

From: EECE 380 Group L2B1

Subject: Weekly Review

Dear Dr. Michelson,

This was a transition week when we wrapped up and demonstrated the swept-tuned spectrum analyzer project, wrote a report for it, and started the Orbcomm project.

During the first demonstration, our project did not behave desirably. It could only precisely describe RF but not FM signals. Therefore, we applied for a one-day extension to upgrade the project’s behavior. While troubleshooting, we figured out that our problem was probably caused by the large capacitor in peak detector and redundant crystals in RBW filter. Due to these issues, the FM signals with low modulation frequencies overlapped to create distortion. Therefore, we redesigned our circuit by replacing the capacitor and eliminating two of the crystals. As a result, the new spectrum analyzer could plot FM signals with modulation frequency as low as 10 kHz, and we successfully demonstrated at Wednesday night.

On Friday, we were given several guides and slides to read through and start working on the second project. In the lab section, our goal was to send emails to the group email account. We completed the task by modifying codes in the APL.c file, and spent rest of the time gaining knowledge on Q4000 instruction.

Next week, our goals are:

• Split tasks and assign to every group member
• Read and learn the Q4000 data sheet, programmer guide and user guide
• Familiarize ourselves with IAR Workbench, QCT and PUTTY

With Regards,

Yuan Liu

Memorandum

EECE 380 Group L2B1

To: David Michelson, Associate Professor, UBC

From: CHUN YEUNG CHOW, Student

Date: March 2, 2014

Subject: Weekly Review

Dear Dr. Michelson,

This is the last week before our first project is due, and we started to combine all the components together early this week. We put the test signal and VCO into the mixer, then connected that into two cascaded CE amplifiers, followed by a Crystal Ladder filter. The precision peak detector was the biggest problem that it was not working desirably. Then we have discussed and figured out that our design could use a simple peak detector instead. Unfortunately, it is still not working properly so far. Moreover, we observed that the gain of our amplifier is not enough and the loss of a tested signal is quite large so we have to come up with different ideas to solve these problems as soon as possible.

We got into the troubleshooting late into the project.  After we put the hardware and software together, we had a lot of problems finding the correct display, mostly because our signal magnitude was too small (less than 35dBm).

For next week our team plans to finish the project as much as possible and begin writing the presentation/report so that we are ready to demo on Wednesday, March 5.

With Regards,

CHUN YEUNG CHOW