Sarah: The system begins with a potentiometer, which acts as the user input by varying resistance as it is rotated. This signal is read by the Arduino and mapped to control the angle of a servo motor. The servo’s lever is extended with a popsicle stick, which pulls on a rubber band as it rotates. The stretching of the rubber band creates tension, which is measured by a load cell. The load cell converts this mechanical force into an electrical signal that the Arduino processes. The output of the load cell is then used to control a set of incandescent light bulbs, which illuminate at different brightness levels depending on the measured tension.

Helios: The system starts with a potentiometer to detect rotational movement from the user and transform the signal into rotational movement for the servo. This rational movement is utilized as a force, and pulls on the rubber band attached to the load cell to detect the amount of force outputted by the servo and rubber band. This signal is finally read by the load cell, and coverted into temperature via the lights to the right of the entire project.

Sarah: The load cell mechanism works by translating the servo motor’s rotation into measurable tension. The servo’s lever is reinforced with electrical tape and attached to a popsicle stick with a hole cut in the middle. At the far end of the stick, another hole is cut to tie a rubber band, which is then knotted to the outermost hole of the load cell. As the servo rotates, it pulls the stick and stretches the rubber band, creating tension that the load cell converts into an electrical signal. Positioning the rubber band at the end of the stick increases the lever arm length, making the system more sensitive to changes in rotation.

Helios: The temperature emitter is just three incandescent light bulbs powered by 5V and turned on and off by a MOSFET connected to the data pins in the Arduino. The interesting and most complicated part of the code was mapping the [0, 1023] range of the potentiometer into the [0, 255] range of each of the lights to allow for a smooth flow from light to light as the potentiometer signal, (or load sensor signal) increased. This was done by multiplying the potentiometer value by 3/4, then setting each light to the range associated with their spot in the sequence. 

Sarah: This video demonstrates how one form of energy (rotation) can be transduced step by step into another, represented as temperature through the dimming of incandescent bulbs. The intended system connects a potentiometer to a servo motor, which applies tension to a load cell. The load cell’s readings are then used to control the brightness of the bulbs.

During testing, I encountered significant troubleshooting challenges. A faulty Arduino produced unexpected errors, and the load cell failed to provide usable readings. As a result, the lightbulbs could not dim or brighten as planned. However, the mechanical chain from the potentiometer to the servo motor and into the load cell functioned correctly, showing that the core transduction pathway was working, even if the final output stage was incomplete.

Helios: This video shows the input (trying) to go through the double transducer to output a final signal by the 3 lights, as well as the skip the middle button working as intended and skipping the middle transducer for a direct input-output.

Sarah: Potentiometer to Servo Motor

This is a breadboard and Arduino wired together, with the potentiometer controlling the servo motor’s lever arm. From this step, we learned how a simple change in resistance could be translated into controlled rotation, giving us a clear understanding of how input values map to physical movement.

Sarah: Incandescent Bulb Wiring

Here, an incandescent bulb is wired into the breadboard and powered through the Arduino using a transistor and resistor. The bulb glows when current passes through, acting as the system’s heat and light output. Through this stage, we learned how to regulate higher-power components safely and how transistors can be used to control brightness effectively.

Sarah: Soldering the Load Cell

This image shows wires being soldered to the load cell while it is secured in a vise, with the vacuum on to remove fumes. Preparing the sensor taught us how to make clean, reliable solder joints and gave us insight into how careful wiring impacts sensor accuracy. We also learned that precise handling during soldering is essential for achieving consistent readings.

Helios: Setting the Lights

This image shows a progress step where the LCD was powered and displaying information while the three incandescent lights were able to be powered and manipulated by the Arduino and potentiometer. It also marked the point in which we knew how we would wire all three lights to the Arduino using the MOSFETs;