# Title Team Members TA Documents Sponsor
55 Automated Drink Maker
Brian Smalling
Charlie Thiery
Luke Singletary
Akshatkumar Sanatbhai Sanghvi final_paper2.pdf
**Team Members**

Luke Singletary

Charles Thiery

Brian Smalling


The problem our group plans to solve is the inefficiency of service at restaurants due to the lack of staff. Many restaurants are severely understaffed due to the pandemic, which has caused an increase in the time for service. This leads to less repeat customers and lower reviews for the restaurant, leading to lost revenue for these establishments. It is crucial for many of these restaurants to keep these repeat customers to stay open during these hard times.


Our solution to this problem is to automate the drink ordering process which would make the restaurant staff's job much more efficient. To do this we would use a Bluetooth remote to send orders to a machine to make these drink orders. The remote would use preset button presses to send a signal to the machine of which drinks to be made. The machine itself would be able to make multiple orders in succession. For this feature, the machine would use a conveyor belt to load and unload cups. It will take a cup and position it under the nozzle, and after the cup has been filled with the ordered drink, it will then move the cup to the unloading area. The filling system will be timed to the flow rate of the nozzle and use small motors to control the amount dispensed for each liquid. The liquids will be gravity fed to the nozzle to help keep costs low for the machine. For all the timing we will use a microcontroller since this can be a complex task since some fluids will have different flow rates.

Solution Components:

System 1:

Our first system will be the remote for the device. The remote will need to have four different buttons for the different drinks to be made. There will also be a Bluetooth transmitter to transmit the drink order to the machine. Lastly, this system will include a AA battery so that the remote will be able to keep a compact size.

System 2:

The next system will be the cup loading and unloading system. We plan to use a small electric motor attached to a gear attached to the conveyor belt. There will also be a photo sensor on the filling platform to confirm that a cup has been properly positioned. This will be done by the photo sensor sending a signal to our microcontroller to stop the belt and as well start a timer for the filling. Once filling is complete the conveyor will then move the cup to a holding area.

System 3:

Our next system will be our filling system that will be made up of four motors. These motors will control the valves for each type of liquid. The liquid will be gravity fed and be held in containers suspended above the conveyor belt. They will all be connected to the same nozzle by their own feeding tubes. The process of filling the cups will be controlled by our micro controller and will precisely let out the exact amount of liquid to properly fill the cups.

System 4:

Lastly, our final system will be our micro controller and Bluetooth receiver system. Our Bluetooth receiver will receive which button has been pressed and then send the signal to the microcontroller. After this the microcontroller will activate the belt to move a cup into position till the photo sensor detects the cup. Then it will activate the motor to begin filling and triggering a timer to turn off these fill motors. These components will be stored in a water resistant protective covering which will also hold the batter pack to power the machine.

**Success Criterion:**

We have a few success criteria for the machine, since we have many components that will need to be working together in unison.
- First our remote is able to send different signals to the receiver properly and at range.
- Secondly, our conveyor belt is able to safely move glasses. It must also properly start and stop the glass in the appropriate positions.
- Then, our filling system is able to open and close the valves to release the same amount of liquid into every cup.
- Lastly, that all of these are able to be properly timed so that all of this occurs in a timely manner with no spillage or breakages.


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.