Team__206.github.io

Hardware Proposal

Bill of Materials in Appendix D

Team Schematic

Figure 16: Team 206 Combined Schemtic

Switching Regulator:

The above schmetic depicts how the circuit layout for each team members combined subsystem would interact with each other in order to how our device function properly. The circuitry begins at the 4.5 volt power source transmitting power through a 3.3 volt switching regulator circuit which utilizes an inductor for energy storage. During the switching operation, the inductor stores energy in its magnetic field when the current through it increases. When the switch turns off, the inductor releases this stored energy to the load. This allows the switching regulator to regulate the output voltage efficiently. In a switching regulator circuit, two resistors in series are often used as a voltage divider network to provide feedback for regulating the output voltage. This feedback mechanism is crucial for maintaining the desired output voltage level. The two resistors form a voltage divider network across the output voltage. The output voltage is compared to a reference voltage (often a fraction of the output voltage) to determine if it needs adjustment.

Temperature Sensor:

In the temperature sensor circuit, pull-up resistors are pivotal components serving two critical functions. Firstly, they facilitate logic level conversion, particularly crucial when sensors employ protocols like I2C or SPI, which require specific logic levels for communication. Pull-up resistors ensure that output signals from sensors, often utilizing open-drain or open-collector configurations, are elevated to the logic high level expected by digital interfaces, enabling seamless data transmission. Secondly, pull-up resistors contribute to noise filtering by maintaining communication lines at a defined logic high level during idle periods, thereby minimizing the impact of electromagnetic interference and enhancing signal integrity.There are three lines, ALERT, SDA and SCL. Starting with ALERT, a preprogrammed condition can be set for the temperature sensor which can allow for the device to automatically send an alert to the microcontroller. Second is the SDA which is a bidirectional line used for transferring data between the microcontroller and temperature sensor using I2C. Lastly there is the SCL, which syncohronizes the communication between the temperature sensor and the microcontroller also using I2C communication

Motor Driver:

In the final circuit configuration, the 9-volt DC motor is controlled through the IFX9201SG motor driver, with communication facilitated by four pins connected to the PIC microcontroller: MISO, MOSI, SS, and CLK. The MISO (Master In Slave Out) pin serves as an output from the microcontroller, transmitting data to the motor driver. Conversely, the MOSI (Master Out Slave In) pin acts as an input, receiving commands or data from the microcontroller. The SS (Slave Select) pin allows the microcontroller to designate the motor driver as the intended recipient of the data being sent in the SPI communication setup. Meanwhile, the CLK (Clock) pin provides the necessary clock signal to synchronize data transfer between the microcontroller and the motor driver, ensuring precise timing and coordination. Together, these pins establish a communication interface, enabling the microcontroller to send control signals to the motor driver for efficient and accurate control of the 9-volt DC motor. The motor driver interfaces with the motor using two output pins, incorporating Schottky diodes to suppress the back electromotive force (BEMF) generated by the motor. The entire circuit operates on a 3.3-volt voltage supply.