Xavier Haupt’s Work Log

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  • Post last modified:February 25, 2024
  • Reading time:7 mins read
  • Post category:Work Logs

Spring 2024

1/27/24: This week the RecycleBot team got together to layout what the new iteration of RecycleBot will look like. With the coming changes I started laying out the electrical box and proposing where the best place to put the power supply and heater controllers would be. My To Do list for the coming week is as follows:

  • Design a more in-depth controls box
    • Decide where power supply, arduino, and wiring will go.
    • Decide a final placement on where the power supply may end up
    • Explore how to connect motor and power supply to one power cord
  • Create electrical parts list and create a draft bill of materials
    • Explore thermistor options
    • Figure out what electrical items are available within the lab
  • Explore funding opportunities
    • Set up meeting with Len Switzer and discuss how to join EMI

2/3/24: This week with RecycleBot continued its development of the initial layout for the extruder module. It was decided that the electrical box will be developed once the initial frame is constructed. With Aluminum extrusion found within the lab it is possible that RecycleBot will not have to wait for the ordering of more extrusion before we can move on to constructing the frame. I started working on circuit diagrams from initial power supply box and will continue to try and flesh out the electronics box for next week. A meeting with Len Switzer showed us that EMI is a good possibility to try and get RecycleBot funded. My To Do list for the coming weeks is as follows:

  • Finish the rough draft of the circuit layout of the electronics box
    • Figure out how to wire thermistors and temperature controllers
    • Learn how our power supply works
  • Continue to work with James to develop the electrical parts list along with bill of materials
  • Explore funding opportunities
    • Draft a proposal and have it submitted to Len Switzer before winter carnival break

2/24/23: The final draft of the EMI proposal has been submitted to Len Switzer. There will be about a two week period in which the EMI team will look over out proposal and give us funding. With the new extrusion barrel delivered work has been started on the electricals of the system. The power supply will

Fall 2023

9/23/23: Continued my Arduino research by diving into the recyclebot.ino code to understand what libraries and functions that are currently implemented for recycle bot. This researched gave me a better understanding of what code needs to change once some of the other functional requirements get met.

From the meeting held on 9/22/23 my goals moving forward is to research how to have the Arduino act a potentiometer for the new auger motor. I also need to look into adding functions which will allow for us to test the cleaning procedures.


Looked into ways around using a physical potentiometer. One of the solutions found was outputting variable voltage from the Arduino using the PWM pins and an RC low pass filter. The PWM would pulse 0 and 5 volts and based off the duty cycle we could control the average voltage. The RC low pass filter was to smooth out the pulses to get a more analog steady state voltage. This implementation could have worked although after further research we have ultimately decided to purchase and use a digital potentiometer.

Using the Adafruit DS3502 I2C Digital Potentiometer and the existing open source libraries we can replace the analog potentiometer(pictured below) and have great digital control over the voltage that needs to be inputted into the motor controller. The digital potentiometer’s “wiper” is adjusted base on an integer from 0 – 127. Using the 3.3Vout from the Arduino the wiper can be adjusted from 0 – 96 to control a voltage from 0 -2.5V. I have started on creating test code for the digital potentiometer.


The digital potentiometer was connected via the I2C pins on the motor shield. This caused the LCD display to be connected to the passthrough I2C port on the digital potentiometer. The digital potentiometers RH(Wiper High) RW(Wiper) were soldered in order to connect into the motor controller. Due to the motor putting pressure on the barrel the potentiometer has yet to be tested with recycle bot functioning.


While some of the issues with the motor screw are being resolved I have started work on flowcharting the interface as well as researching how we can interface with the Arduino via the rotary encoder we have. The current idea is to use the rotary encoder to start the extrusion process as well as access menus in which motor speeds could be adjusted.