This week our team worked on slides and presented for the interim demo. Olek and I also worked together on Wednesday evening to set up an Arduino to communicate over I2C with the Raspberry Pi.
This week I finalized the sensor data schematics and finished the layout of the board. I generated the gerber files and the bill of materials and uploaded them to PCBway to receive a quote which came out to around $82 not including shipping. I am currently waiting for PCBway to review the board so that I can order it. I am behind schedule, so in order to receive and debug the board in time I am planning on paying for the board to be manufactured out of house and for expedited shipping using our remaining budget.
My goals for the week are to have the PCB design approved, ordered, receive the board, and start testing it and integrating it with the Raspberry Pi for the final showcase.
ABET #6 says … An ability to develop and conduct appropriate experimentation, analyze and interpret data, and use engineering judgment to draw conclusions
Now that you are entering into the verification and validation phase of your project, provide a comprehensive update on what tests you have run or are planning to run. In particular, how will you analyze the anticipated measured results to verify your contribution to the project meets the engineering design requirements or the use case requirements?
Thus far, I have simulated a simple sensing circuit using the force sensing resistor sensors, potentiometers, and an LED. I tested different values for the potentiometer to ensure that the voltage output would cover the full range of the ADC. I found a value for the potentiometer that covers as much voltage range as possible whilst also illuminating the LED.
When the pressure sensor data collection board arrives, first I will test the power conversion circuitry to make sure my 5V and 3V3 rails are working. Then I’ll test that the ADC I2C chip is working correctly by ensuring the Raspberry Pi is receiving I2C packets from the PCB. Then I’ll mess around with the sensors to see if I need to change any resistance values to alter voltage levels or change my RC filter.