# Title Team Members TA Documents Sponsor
Evan Dawson
Homero Vazquez
Michael Tzeng
Akshatkumar Sanatbhai Sanghvi design_document3.pdf

Team Members:
- Evan Dawson (evanfd2)
- Michael Tzeng (mhtzeng2)

# Problem

Heating up liquids like soup or water can be time consuming and inconvenient with the need for a pot or kettle. These solutions involve the transfer of the hot liquid to another container that is usually thermally insulated to keep the liquid warm.

# Solution

We are proposing a unique all in one induction heating solution in the form of a water bottle that will heat up your desired liquid and keep it warm. The bottle includes multiple shells that insulate and heat the liquid, as well as protect the user from the heated shell. The user can also select the desired temperature and view the current temperature of the liquid in the bottle with our UI.

# Solution Components

## Shell 1: Liquid holding container/Heat Transfer layer
- One way heat transfer, high melting point, non inductive material
- Copper, aluminum, brass
- Temperature Sensors connected at heat transfer points, which then connect to the temperature control unit.
- TMP36GT9Z (analog temperature sensor)
- These temperature sensors control ventilation system states to ensure single-directional average heat transfer.

## Shell 2: Inductive System Layer
- High melting point, easily heated material with a vacuum inside to isolate the magnetic coils from the rest of the design.
- Steel or Iron is a heavier material, but more Ideal for this application
- Complex ventilation system built within this layer
- Electrical components stored outside of the magnetic area, but with access to the ventilation system.

## Shell 3: Protection/Outside
- Stainless Steel, low heat conduction, light, cheap, easily molded, perfect for protecting the inductive layer from outside interference.
- Ventilation system is integrated to have points of exit around the stainless steel layer.
- UI/Display integrated into steel mold.

## Induction Subsystem
- Induction generator that supplies power to the battery subsystem and induction coils. Generator also receives power from the battery subsystem for initial start.
- Induction coils will surround the heat transfer layer, and be divided in three places (bottom, middle and top of the bottle) to avoid coils overheating
- Induction Generator includes Electromechanical and/or Electromagnetic energy conversion components, for multiple methods of charging.

## Battery Subsystem
- Rechargeable battery powered by induction generator (can also supply energy to generator once battery has recharged)
- AA/AAA battery as primary power source to start induction generator

## User Interface + Processing Unit
- Flexible LED display that shows the current temperature or desired temperature of liquid
- Flexibility allows for wrapping around the circular shaped bottle

- Buttons that allow user to select desired temperature of liquid

- Custom processor that bridges between user input and bottle display, routes temperature data to LED display, and calculates desired temperature based on user input
- Communicates to induction generator when to supply power and when to stop

# Criterion For Success
## Temperature Control
Bottle must be able to maintain a given temperature value (70°-150° F/ 294.261 K - 338.706 K)
Bottle must have a heating system in place to raise or lower temperature at will.
This will be done with a series of induction heating coils, and a ventilation system to send heat into liquid through a conductive material or release heat into the outside world.

## Rechargeable Battery
Power source for the Temperature control and other aspects of the bottle must be reusable/rechargeable in order to avoid replacing the battery and ensure long-term use.
An Induction Generator, which can use a magnetic induction system to charge the battery on a wireless pad, or an Electromechanical energy conversion system to harness the motion of users to induce a moving magnetic field.
The moving magnetic field would be used to generate current for the induction coils and for recharging the battery.


Shamith Achanta, Rick Eason, Srikar Nalamalapu

Featured Project

Team Members:

- Rick Eason (reason2)

- Srikar Nalamalapu (svn3)

- Shamith Achanta (shamith2)

# Problem

The Aerospace Engineering department's Laboratory for Advanced Space Systems at Illinois (LASSI) develops nanosatellites for the University of Illinois. Their next-generation satellite architecture is currently in development, however the core bus does not contain an Attitude Determination and Control (ADCS) system.

In order for an ADCS system to be useful to LASSI, the system must be compliant with their modular spacecraft bus architecture.

# Solution

Design, build, and test an IlliniSat-0 spec compliant ADCS module. This requires being able to:

- Sense and process the Earth's weak magnetic field as it passes through the module.

- Sense and process the spacecraft body's <30 dps rotation rate.

- Execute control algorithms to command magnetorquer coil current drivers.

- Drive current through magnetorquer coils.

As well as being compliant to LASSI specification for:

- Mechanical design.

- Electrical power interfaces.

- Serial data interfaces.

- Material properties.

- Serial communications protocol.

# Solution Components

## Sensing

Using the Rohm BM1422AGMV 3-axis magnetometer we can accurately sense 0.042 microTesla per LSB, which gives very good overhead for sensing Earth's field. Furthermore, this sensor is designed for use in wearable electronics as a compass, so it also contains programable low-pass filters. This will reduce MCU processing load.

Using the Bosch BMI270 3-axis gyroscope we can accurately sense rotation rate at between ~16 and ~260 LSB per dps, which gives very good overhead to sense low-rate rotation of the spacecraft body. This sensor also contains a programable low-pass filter, which will help reduce MCU processing load.

Both sensors will communicate over I2C to the MCU.

## Serial Communications

The LASSI spec for this module requires the inclusion of the following serial communications processes:


- RS422

- Differential I2C

The CAN-FD interface is provided from the STM-32 MCU through a SN65HVD234-Q1 transceiver. It supports all CAN speeds and is used on all other devices on the CAN bus, providing increased reliability.

The RS422 interface is provided through GPIO from the STM-32 MCU and uses the TI THVD1451 transceiver. RS422 is a twisted-pair differential serial interface that provides high noise rejection and high data rates.

The Differential I2C is provided by a specialized transceiver from NXP, which allows I2C to be used reliably in high-noise and board-to-board situations. The device is the PCA9615.

I2C between the sensors and the MCU is provided by the GPIO on the MCU and does not require a transceiver.

## MCU

The MCU will be an STM32L552, exact variant and package is TBD due to parts availability. This MCU provides significant processing power, good GPIO, and excellent build and development tools. Firmware will be written in either C or Rust, depending on some initial testing.

We have access to debugging and flashing tools that are compatible with this MCU.

## Magnetics Coils and Constant Current Drivers

We are going to wind our own copper wire around coil mandrels to produce magnetorquers that are useful geometries for the device. A 3d printed mandrel will be designed and produced for each of the three coils. We do not believe this to be a significant risk of project failure because the geometries involved are extremely simple and the coil does not need to be extremely precise. Mounting of the coils to the board will be handled by 3d printed clips that we will design. The coils will be soldered into the board through plated through-holes.

Driving the inductors will be the MAX8560 500mA buck converter. This converter allows the MCU to toggle the activity of the individual coils separately through GPIO pins, as well as good soft-start characteristics for the large current draw of the coils.

## Board Design

This project requires significant work in the board layout phase. A 4-layer PCB is anticipated and due to LASSI compliance requirements the board outline, mounting hole placement, part keep-out zones, and a large stack-through connector (Samtec ERM/F-8) are already defined.

Unless constrained by part availability or required for other reasons, all parts will be SMD and will be selected for minimum footprint area.

# Criterion For Success

Success for our project will be broken into several parts:

- Electronics

- Firmware

- Compatibility

Compatibility success is the easiest to test. The device must be compatible with LASSI specifications for IlliniSat-0 modules. This is verifiable through mechanical measurement, board design review, and integration with other test articles.

Firmware success will be determined by meeting the following criteria:

- The capability to initialize, configure, and read accurate data from the IMU sensors. This is a test of I2C interfacing and will be tested using external test equipment in the LASSI lab. (We have approval to use and access to this equipment)

- The capability to control the output states of the magnetorquer coils. This is a test of GPIO interfacing in firmware.

- The capability to move through different control modes, including: IDLE, FAULT, DETUMBLE, SLEW, and TEST. This will be validated through debugger interfacing, as there is no visual indication system on this device to reduce power waste.

- The capability to self-test and to identify faults. This will be validated through debugger interfacing, as there is no visual indication system on this device to reduce power waste.

- The capability to communicate to other modules on the bus over CAN or RS422 using LASSI-compatible serial protocols. This will be validated through the use of external test equipment designed for IlliniSat-0 module testing.

**Note:** the development of the actual detumble and pointing algorithms that will be used in orbital flight fall outside the reasonable scope of electrical engineering as a field. We are explicitly designing this system such that an aerospace engineering team can develop control algorithms and drop them into our firmware stack for use.

Electronics success will be determined through the successful operation of the other criteria, if the board layout is faulty or a part was poorly selected, the system will not work as intended and will fail other tests. Electronics success will also be validated by measuring the current consumption of the device when operating. The device is required not to exceed 2 amps of total current draw from its dedicated power rail at 3.3 volts. This can be verified by observing the benchtop power supply used to run the device in the lab.