Project

# Title Team Members TA Documents Sponsor
54 Pancake Flipper
 David Lin
James Lu
Jason Kim
 Abhisheka Mathur Sekar design_document2.pdf
final_paper1.pdf
other1.jpg
photo1.jpg
presentation2.pptx
proposal2.pdf
Team Members:
- James Lu (jameslu2)
- Jason Kim (jasonsk3)
- David Lin (davidzl2)

# Problem
When flipping pancakes at home, many things can go wrong. For example, the pancake can rip, fold on itself, burn, and deform. There are many tools that automate making pancakes, but they have set sizes for the pancakes. This is an issue for varying appetite sizes.

# Solution

Describe your design at a high-level, how it solves the problem, and introduce the subsystems of your project.
Our design automates the task of flipping pancakes. It is a device that can be used on a home and portable stove. The device has a metal plate that is placed directly on top of a heat source such as a stove. Pancakes are cooked on the metal plate. Using various sensors, an appropriate duration for cooking the pancake is determined to avoid undercooking or burning. After the cooking period, the pancake is flipped, and another timer is set to cook the other side. With automation, pancakes are less prone to ripping, folding, and deforming during the flipping process. This device allows the user to cook a pancake with a size of their choice by letting the user pour the batter manually. The subsystems include the timer, the message system, the pancake measurement system, the temperature sensor, and the flipper.


# Solution Components

## Subsystem 1 Timer

The timer is adjusted according to the size of the pancake, it basically sets a certain amount of time that the pancake needs to be cooked before it gets flipped. By doing so, the system makes sure to avoid overcooking and undercooking.

Possible Timer: DC 5V-36V Timer Module Trigger Cycle Delay Timer Switch Turn On/Off Relay Module with LED Display
## Subsystem 2 Pancake Measurement System
The pancake measurement system provides an estimate for the size of the pancake which is used as an input to calculate how long the pancake batter should be cooked before flipping. In order to obtain an estimate for the size of the pancake, an ultrasonic sensor is moved along the center of the metal plate facing downward onto the pancake. The difference in distance between the sensor and both the pancake and the plate, along with the speed of the sensor as it moves across the center of the plate, is used to calculate the pancake's diameter for size estimation. The calculations will be done in the MCU.

Possible ultrasonic sensor: cusa_t75_18_2400_th
Possible MCU: STM32F303K8T6TR

## Subsystem 3 Temperature Sensor
The temperature sensor measures the temperature of the stove and the surface temperature of the pancake. Once the temperature sensor detects a certain temperature on the stove, the system will notify the display bar to display the message of letting the user pour the batter. Once the pancake is flipped, the temperature sensor will then start detecting for a certain temperature which would tell the user that the pancake is ready. By using the temperature sensor, the system makes sure that the pancake is thoroughly cooked.

Possible temperature sensor: Amphenol JS8746B-0.20 Industrial Temperature Sensors

## Subsystem 4 Display Bar
The display bar tells the user the instructions to make the pancake, such as when to start pouring the batter, when the pancake is ready. The display bar is triggered by the temperature sensor detection, in that way, the system ensures to provide the users with the correct instructions.

## Subsystem 5 Flipper

When it is time to flip the pancake, the MCU will control some servos in order to create a flipping motion.

# Criterion For Success

Describe high-level goals that your project needs to achieve to be effective. These goals need to be clearly testable and not subjective.
Successfully flipping the pancake without folding and ripping
Make sure the pancake is thoroughly cooked by measuring internal temperature.
The ultrasonic sensor subsystem should be able to return the diameter of the pancake.
Timer is adjusted to the size of the pancake.
Display bar displays the correct message at the correct time.

ATTITUDE DETERMINATION AND CONTROL MODULE FOR UIUC NANOSATELLITES

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:

- CAN-FD

- 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.