System Integration

The assignments for this week:

Design and document the system integration for your final project

Features of the Aqua Buddy

The Aqua Buddy is a silicon band with an indicator which can be worn around a bottle to remind a person to drink water and stay hydrated. It's features include :

Sensing Motion: The band would can detect motion or movement. The sensors would continuously monitor the position and orientation of the water bottle.

Detecting Inactivity: If the water bottle remains stationary for a certain duration, it indicates that the person hasn't lifted the bottle to drink water.

Triggering Reminders: Once the band detects prolonged inactivity, it would trigger a reminder to encourage the person to drink water. This reminder is a notification with a light and an audible alarm.

Water Quantity:Measure water level in the bottle.

Adjustable Settings: The band could include adjustable settings to customize the reminder frequency and intensity based on individual preferences and hydration needs. For example, users could set the duration of inactivity before receiving a reminder and choose their preferred reminder method.

Integration with the phone: The band will be integrated with phones via Bluetooth or Wi-Fi connectivity. This integration would allow users to receive notifications on their phones.

Comfort and Durability: The band will be designed for comfort and durability to ensure it can withstand daily use and be worn comfortably around the water bottle without causing discomfort or hindering usability.

Production methods

Electronic Circuit and PCB Production:

Design: Draw the schematic and design the PCB in KiCad.

Manufacture: Mill the PCB board and solder the components.

Program: Test the board and program it to blink the LED and sound alarm in time intervals.

3D Printing for Housing:

Design housing unit:

Design the housing unit in Fusion360 such that the PCB fits well.
Design the clips for the band

Print:

3D print the housing using materials like PLA or TPO.
Print the clips of the silicon band.

Silicone Band Production with 3D-Printed Mold:
This method involves creating a mold using a 3D printer and then casting silicone into the mold.
Steps:

Design and Print the Mold: Create a 3D model of the mold and print it.

Prepare the Silicone: Mix and pour the silicone into the mold.

Cure the Silicone: Allow the silicone to cure in the mold.

Demold the Band: Remove the cured band from the mold.

Interface:

Design the User Interface in Kodular.

B.O.M.

COMPONENT	PACKAGE NAME	QUANTITY	COST
Microcontroller	XIAO ESP32	1	699
3-axis accelerometer	ADXL 345	1	99
Reminder Component-a	Neopixel LED	1	359
Reminder Component-b	Speaker	1	42
Capacitive sensors	Copper tape	1	177
Resistors	1kohm,499ohm,10kohm	TBA	--
Capacitors	100nF,10mF,10nF	TBA	--
Header Pins	1X08,1x04,1x03	1 each	--
Battery	Li rechargeable battery	1	125
PCB	Copper	1	--
Connectors	Jumper wires	4	--

Project Schedule

TASK TITLE	START DATE	DUE DATE	DURATION
1
1.1 Research and finalize the PCB design (schematic and routing and collect components)	20-May	21-May	2
1.2 Solder the components and check for blink	21-May	21-May	1
1.3 Program for alarm and blink Neopixel	22-May	24-May	3
2
2.1 Design the 3D model for the mold for the silicon band	19-May	19-May	1
2.2 Design the housing unit and how to put the halves together	19-May	19-May	1
3
3.1 Make prototypes for the housing unit and cast the band - 3D print and test	22-May	24-May	3
3.2 3D print housing unit	24-May	27-May	4
4
4.1 Make a user interface	28-May	30-May	3
4.2 Test the UI and the interaction with the band's features	30-May	1-Jun	2
5
5.1 Complete documentation	20-May	3-Jun	14
5.2 Video editing	4-Jun	5-Jun	2

Block Diagram

Xiao ESP32: This is the central microcontroller unit (MCU) that includes built-in WiFi and Bluetooth capabilities and provides the necessary GPIO pins for interfacing with other components.

ADXL345 Accelerometer: Connected via I2C to the Xiao ESP32 to detect motion and orientation of the water bottle.

Capacitive Sensors: Three individual sensors connected to specific GPIO pins on the Xiao ESP32 to measure water level in the bottle.

NeoPixel LED Strip (WS2812): Controlled by the Xiao ESP32 to provide visual feedback.

Speaker with Amplifier (PAM8403): Controlled by the Xiao ESP32 to provide audio reminders or alerts.

Power Supply: This includes both 3.3V and 5V supplies. The Xiao ESP32 and capacitive sensors typically use 3.3V, while the NeoPixel LED strip and speaker amplifier use 5V.

Phone User Interface:The Xiao ESP32 communicates wirelessly with the phone UI using either WiFi or Bluetooth. This connection allows the phone to send commands to and receive data from the Xiao ESP32, such as adjusting reminder settings or monitoring water consumption data.

Change of plans!!

The idea was to use an accelerometer and detect any tilt in the bottle as an activity and to trigger reminders when there is inactivity. But my instructors, Jogin and Saheen suggested to test step response on the bottle with two copper strips. It worked! So, I changed my initial designconcept to this:

second concept

Now this means a new schedule, since there is no silicon band anymore.

second conceptb

Revised B.O.M.

S.No.	COMPONENT	SOURCE	QUANTITY	COST
1	Microcontroller-Xiao ESP32C3	Fablab	1	699
2	LED RGB Clear	Fablab	1	40
3	Mobile Speaker	Local shop	1	10
4	Copper Tape	Fablab	18cm x 3cm strip	-
5	Resistors	Fablab	5	5
7	Battery-LiPo LP251 320 40mAh	Local shop	1	120
			Total(INR)	874
			Total(USD)	10.52