Overview of Status of Analysis, Design, Fabrication, Tests, etc.
Began PVDF sensor connection encasement once epoxy adhesives arrived
Waiting on the arrival of more glue gun nozzles to complete the connection encasement
Once the sensors are encased and arranged on the acrylic face, we will test for location data using an impulse hammer and will represent the data obtained using some kind of heat map.
External, fast sampling analog to digital converter, 8 to 1 multiplexer, operational amplifiers, and diode bridge rectifier components have been ordered from Digi-Key, expected arrival 4/13
Signal conditioning circuitry to convert differential PVDF sensor readouts to single ended sensor readouts has been developed and a rudimentary test has been established and confirmed the operation of this circuit while electronics are shipping
Teensy microcontroller has proven it can achieve sampling rates required with its onboard analog to digital converters, and next design decision will be whether to use these ADCs or an externally interfaced ADC with better, more robust specifications
Software and read/write speeds are a new bottleneck in data acquisition system, even writing to the onboard EEPROM memory on the Teensy microcontroller might be too slow. A perfectly optimized sampling rate beneath the read/write speeds of the onboard memory, but with enough speed to collect the impulse data will be necessary
EEPROM memory has a guaranteed life of 100,000 write cycles per memory address, which should be enough to survive the life of the club, but an external, fast writing memory might be necessary to eliminate the worry of write cycle life, and give a larger amount of storage capability
Test to identify exact voltages emitted from new and encased PVDF sensors to create voltage division circuitry for exact strain percentages expected in impact
NRF24L01wireless transceivers are confirmed to be a good fit for our project needs, but we need to experiment how fast it can send the data to the other transceiver
MATLAB is a good program that can interact with the data from the Arduino, so we will be using MATLAB to display, interpret, and analyze the data
Accomplishments from Previous Week
Started PVDF sensor connection encasement (Kaitlynn)
Handed off PVDF sheet for automated cutting (Kaitlynn)
Handed off soldering kit for DAQ/electronics use (Kaitlynn)
Sent CAD file for test stand to ARMOR Lab employee (Reuben)
CAD PVDF cut (Reuben)
Received/Verified dimensions of Laser cutout golf face (Reuben)
Confirmed compatibility of NRF24L01wireless transceivers with Arduino Uno, Arduino Mega, and Teensy micro-controller (Michelle)
Confirmed the decision of using Arduino Mega to receive data from the Teensy micro-controller and chose MATLAB to interpret, analyze, and display the wanted strike characteristics (Michelle)
Developed preliminary signal conditioning circuitry to read differential PVDF sensors in single ended analog to digital converter channels (Chris)
Optimized code for very high sampling rates with Teensy 4.0 microcontroller and onboard dual ADCs. (Chris)
Read PVDF sensors on single ended Teensy channels. (Chris)
Goals for Next Week (list names after each item). Use specific and measurable objectives.
Finish PVDF sensor connection encasement; waiting for more glue gun nozzles to arrive ETA 13 April (Kaitlynn)
Adhere PVDF sensors to acrylic golf faces for testing (Kaitlynn)
Impulse hammer location testing on acrylic face (Kaitlynn and Reuben)
Represent location testing results using a heat map on Matlab (Kaitlynn and Reuben)
Retrieve 3D printed test stand from ARMOR Lab (Reuben)
Inquire about automated cutter in ARMOR Lab (Reuben)
CAD file to cut PVDF sheet (Reuben)
Purchase test setup hardware from Home Depot (Reuben)
Send test results to Michelle for data analysis coding (Kaitlynn and Reuben)
Experiment with the data transmission speed of the NRF24L01 and the maximum operating distance away between two transceivers (Michelle)
Start the skeleton MATLAB code that is able to grab and analyze the data received by the Arduino Mega (Michelle)
Develop method for fast storage of very fast analog to digital conversion data, because serial monitor baud rate is now a bottleneck (Chris)
Continue developing signal conditioning circuitry (what voltage division is necessary), and investigate multiplexing at different points in the circuit to reduce necessary components per sensor (Chris)
Develop accelerometer triggering electronics to begin sampling when club is in significant swing motion (Chris)
Develop voltage reference circuitry for onboard Teensy analog to digital converters (Chris)
Investigate if external, Serial Peripheral Interfacing analog to digital converter is necessary or if onboard Teensy analog to digital converters are acceptable (Chris)
Sponsor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)
Dr. Loh approves us ordering an impulse hammer (~$700) to better replicate the force involved during impact (4/8 via Zoom)
There is an automated cutter in ARMOR Lab that we can use to cut the PVDF strips at better precision. Ann would know more about it (4/8 via Zoom)
Dr. Loh confirms that determining impact angle is a low priority. He would prefer we have better results on location and force (4/8 via Zoom)
Dr. Loh hasn't been able to get the index number for us. He recommends ordering ourselves and getting reimbursed since reimbursements are going through a different index. This may be an issue if we order the impulse hammer since we would prefer not to pay ~$700 out of pocket (4/8 via Zoom)
Dr. Loh can put us in contact with former students to have a wider variety of contacts to address electrical engineering concerns (4/8 via Zoom)
Instructor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)
Ed offered to help with Arduino/Matlab if needed (4/6 via Zoom and email)
Darren: include page number on slides, cite references from literature, write full word before using abbreviation (4/6 via Zoom)
Darren: Keep angle in mind for making our current design compatible (4/6 via Zoom)
Dr. T suggested a different tape (poly-something?) other than painters tape; we used painters tape for rapid prototyping but are open to exploring other insulative adhesives. We couldn't hear the name of the suggested tape so need to confirm that at our next meeting (4/6 via Zoom)
Dr. T asked if the data will be displayed real time or collected and broadcast later with the Teensy; we are planning to write to the Teensy memory and broadcast the data later since the impact occurs over such a short time (4/6 via Zoom)
A pendulum has merits for impact testing and can be well calibrated (4/6 via Zoom)
Comments from Other Students in the Class (indicate date of comments and if via email or in person)
Look into analysis on applying force to an acrylic face (4/6 via Zoom)
Make sure that since we are testing statically, that the electronics will be able to withstand a dynamic impact (4/6 via Zoom)
Risks and Areas of Concern
Need a storage method or transmission method that can perform at speeds that are comparable to the analog to digital converter sampling and conversion rate. This might be difficult to accomplish.
Resources or Information Required but not Available
N/A
Schedule
Impulse hammer testing
Budget (list amount spent and amount remaining)
Amount spent: $499.51
Amount remaining: $2,400.49
Progress on Report and Webpage
Start working on Impact on Society and Professional Responsibility sections on 4/13
Revise/update Home page and add Multimedia