Differences

This shows you the differences between two versions of the page.

--- report:dvp [2026/04/12 21:30] – [Smart System] epsatisep
+++ report:dvp [2026/04/30 17:58] (current) – [7.4.2 Smart System] team5
@@ Line 50: / Line 50: @@
-Phase 1:
+**Phase 1: **
 On the metro, you touch a handrail. The handrail is a tube that contains a sensor and a light. The spot where you touch the pole lights up in a color: your color. Your color then travels visibly through the pole up to the ceiling of the metro.
 On the ceiling of the metro there are LEDs. Your color appears on the ceiling through these LEDs. If another person touches a different pole, their color also appears on the ceiling, and your colors blend together.
-Phase 2:
+**Phase 2:**
 Near the exit doors, there is a QR code that creates a bridge from the visual interaction to a more personal level. After scanning it, a minimalist webpage opens with two main options: “Send” or “Read”
@@ Line 73: / Line 73: @@
-== 7.4.1 User Interface for the Message Page ==
+**User Interface for the Message Page**
-<figure fig:Mockups_Message Page>
+The following Figur shows the 4 main screens of our web application. Screen one is the start screen, it includes the logo a two buttons to decide between "Send Message" and "Read Message". In the second screen the people can type their messages and publish them. In screen three they can see their own published message, and the last screen shows the message of another person.
-{{:report:bildschirmfoto_2026-03-29_um_10.40.20.png?400|}}
+<WRAP centeralign>
+<figure fig:Mockups_Message_Page>
+{{:report:bildschirmfoto_2026-03-29_um_10.40.20.png|}}
 <caption>Mockups Message Page</caption>
 </figure>
+</WRAP>
  The web interface, accessible via QR code, is designed in a minimalist style. After scanning the QR code, users are redirected to the web application's landing page. The CONNECT logo takes center stage here, accompanied by two clickable buttons that lead to the subsequent sections. Within the app, users can choose between composing a message for others or viewing messages written by the community. Our primary focus was to keep the application as simple as possible; we wanted to ensure that both young and old users can navigate it effortlessly. By eliminating the need for logins or complex navigation, we’ve made the experience accessible and time-efficient for everyone.
+=== 7.4.1 Structure ===
+Figures {{ref>fig:initial_drawing}}, {{ref>fig:final_drawings}}, and {{ref>fig:final_final_drawings}} present the evolution of the structural design across successive iterations. Each version reflects an increase in geometric precision, component integration, and manufacturability, progressing from early conceptual layouts to a fully defined enclosure suitable for system integration.
-== 7.4.2 Design System ==
+<WRAP centeralign>
+<figure fig:initial_drawing>
+{{ :report:page_1.png?direct&800  | Initial drawing}}
+<caption>Initial structural drawing</caption>
+</figure>
+</WRAP>
-<figure fig:styleguide>
+<WRAP centeralign>
-{{:report:styleguide.png?400|}}
+<figure fig:final_drawings>
-<caption>styleguide</caption>
+{{ :report:final_drawing.png?direct&800 | Intermediate drawing}}
+<caption>Intermediate structural drawing</caption>
 </figure>
+</WRAP>
-To ensure a consistent user experience and streamline the development process, our project is built upon a custom-developed, comprehensive Design System. This serves as the central framework for all visual and functional interfaces within our web application.
+<WRAP centeralign>
+<figure fig:final_final_drawings>
+{{ :report:final_drawing_v3.png?direct&800 | Final drawing}}
+<caption>Final structural drawing</caption>
+</figure>
+</WRAP>
-Importance of the Design System for our Project
+The transition from preliminary sketches to detailed structural drawings (see Figure {{ref>fig:final_final_drawings}}) marked a key milestone in the project. At this stage, the spatial constraints of all subsystems were clearly defined, including the placement of electronic components, routing of wiring, and mounting strategy. This enabled the development of a specialized Bill of Materials (BoM), as presented in Table {{ref>components_ideal}}, where component selection was directly informed by mechanical, environmental, and regulatory requirements.
-A unified design system is essential to the success of our product for the following reasons:
+Three primary constraints shaped the structural design: enclosure material selection and regulatory compliance, integration of communication hardware within a constrained geometry, and accommodation of power distribution components.
-- Consistency: Users can recognize the brand instantly. A cohesive appearance builds trust and conveys professionalism.
+ **Enclosure Material and Regulatory Complianc**
-- Development Efficiency: By defining reusable components, there is no need to "reinvent the wheel" for every new feature.
+The enclosure design aims to ensure compatibility with metro environments, where safety requirements are critical. In particular, EN 45545-2 imposes strict constraints on material flammability and smoke emission. Initial concepts considered PLA due to its accessibility for rapid prototyping. However, due to its poor fire resistance, it is not suitable for real deployment. For this reason, the design considers Polyamide (PA) Rail as a future implementation material, as it meets railway fire safety standards. At the current prototype stage, this requirement is addressed conceptually, with the enclosure geometry designed to be compatible with such materials, while fabrication remains focused on accessible prototyping methods.
-- Scalability: New functions can be integrated seamlessly because design rules (layout grids, spacing, colors) are already established.
+ **Mechanical Integration and Mounting**
-- Accessibility: By strictly defining contrasts and font sizes, we ensure that the application remains accessible to all target groups.
+The structural design defines the placement and fixation of internal components, including PCBs, sensors, and power elements. Mounting points are incorporated to allow secure attachment of the PCBs using standard fastening methods (e.g., screws and standoffs), ensuring mechanical stability under vibration and movement conditions typical of public transport environments. The enclosure also considers accessibility for assembly and maintenance, allowing access to connectors and internal components without requiring complete disassembly.
-**Core Components of our Style Guide**
+ **Wiring and Internal Layout Considerations**
+Although detailed cable routing is not fully defined at this stage, the structural design accounts for basic wiring requirements. Dedicated entry and exit points for cables are considered, along with internal space allocation for routing. Particular attention is given to the separation of power and signal lines, in order to reduce potential electrical interference and improve system reliability. These considerations will guide future iterations of the design, where detailed routing and harnessing will be implemented.
-**Color Palette**
+ **Thermal and Environmental Considerations**
-Our color strategy is deeply rooted in the application's functionality.
+The system includes components such as DC-DC converters and LED drivers, which generate heat during operation. At this stage, thermal management is addressed through basic passive strategies, including spacing between components and the potential inclusion of ventilation openings in the enclosure. Environmental protection (e.g., against dust and humidity) is considered at a conceptual level, with the enclosure intended to evolve toward a more sealed and robust design in future iterations.
-- Contextual Derivation: The primary colors and their respective shades were derived directly from metro line branding. This ensures high recognition and creates an immediate visual link to the urban mobility context.
-- Color Hierarchy: We utilize a system of primary, secondary, and accent colors, complemented by a grayscale palette for backgrounds and text to effectively manage visual hierarchy.
+The BoM presented in Table {{ref>components_ideal}} reflects the current stage of the design, combining prototyping components with elements selected based on future deployment requirements.
-**Typography**
+While some components (such as enclosure materials) are specified with industrial standards in mind, others are selected to support rapid prototyping and testing. This hybrid approach allows validation of system functionality while maintaining a clear path toward a more robust, deployment-ready solution.
+<table components_ideal>
+<caption>List of components for the product</caption>
+<WRAP center round box 1100px>
+^ Name ^ Type ^ Supplier & more details ^ Additional notes ^  Price (€) ^  Quantity ^  Total (€) ^
+| Microcontroller | Wemos C3 mini | [[https://mauser.pt/095-1308/seeed-113991054-microcontrolador-seeed-studio-xiao-esp32c3-c-wi-fi-bluetooth-5-0-e-carregamento-de-bateria|Link]] | 1 is main board, others are support ones |  6.20 |  11 |  68.20 |
+| Box for electronics equipment | PA Rail | [[https://nanovia.tech/en/ref/nanovia-pa-rail/|Link]] | Fire resistant, could not find a Portuguese supplier (this one is French) |  69.30 |  2 |  138.60 |
+| Copper tape |  | [[https://mauser.pt/095-6889/fita-condutora-de-cobre-adesiva-20mm-20m|Link]] |  |  8.86 |  15 |  132.90 |
+| Pressure sensor | Velostat | [[https://mauser.pt/096-9473/adafruit-1361-folha-de-velostat-piezoresistiva-p-sensores-de-pressao-wearable|Link]] |  |  7.90 |  15 |  118.50 |
+| CAN Transceiver | MCP2551-I-P | [[https://mauser.pt/001-1903/circuito-integrado-mcp2551-i-sn|Link]] | At 26.03 not in stock, email store to check availability |  1.99 |  10 |  19.90 |
+| LED strip with covers | Addressable RGB | [[https://www.amazon.es/dp/B01CNL6K52/ref=asc_df_B01CNL6K52?mcid=2fed6cd8fc303e129f0f7bf9a7df3d53&language=pt_PT&tag=ptgogshpadde-21&linkCode=df0&hvadid=718274527647&hvpos=&hvnetw=g&hvrand=10431677883703446528&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9218545&hvtargid=pla-408656678064&gad_source=1&th=1|Link]] |  |  30.49 |  3 |  91.47 |
+| Power supply (12 V) | DC-DC converter | [[https://www.worten.pt/produtos/modulo-conversor-dc-step-down-36v-72v-para-12v-10a-120w-regulador-de-voltaje-fuente-de-alimentacion-mrkean-5046628495403|Link]] | 2 m strips draw 7.2 A at full power (~30 % reserve) |  24.67 |  6 |  148.02 |
+| Power supply (5 V) | DC-DC converter | [[https://www.worten.pt/produtos/modulo-conversor-dc-72v-para-5v-25a-75w-regulador-de-voltaje-com-caixa-de-aluminio-conversao-buck-mrkean-5046628823572|Link]] |  |  37.15 |  1 |  37.15 |
+| Wiring, resistors etc. |  | [[https://mauser.pt/104-7036/resistencia-de-filme-metalico-1kr-0-6w-1-2-5x6-8mm|Link]] | Really cheap |  10.00 |  1 |  10.00 |
+| Delivery cost |  | Stationary store | To be reviewed |  0 |  1 |  0 |
+| Total Project Cost |  |  |  |  |  |  764.74 |
+</WRAP>
+</table>
+(//iv//) 3D model with load and stress analysis;
+(//v//) colour palette.
-- Typographic Scale: We use a fixed scale for font sizes, line heights, and weights.
-- Application: This scale is applied consistently across all touchpoints from large headlines for orientation to optimized body text for detailed information. This guarantees a harmonious typographic appearance on all devices.
+=== 7.4.2 Smart System ===
-**UI Component Library**
-A key part of the system is the library of reusable elements:
+**Hardware**
-- Modularity: All elements, such as buttons and input fields, were developed modularly.
+Figure {{ref>fig:black_box_diagram}} presents the black box diagram, which includes all the major systems that will be used for our Smart System.
-- Optimization: Components are specifically optimized for web application requirements (e.g., clear click targets, feedback states like hover or disabled).
+<WRAP centeralign>
+<figure fig:black_box_diagram>
+{{ :report:black-box-diagram.png?nolink | **Black Box Diagram**}}
+<caption>Black Box Diagram</caption>
+</figure>
+</WRAP>
-- Reusability: Developers can easily access these components, which reduces the margin for error and seamlessly translates the design into the technical implementation.
-The Design System forms the visual foundation of our project. It bridges the gap between aesthetic brand identity and technical precision, ensuring that the web application is perceived as a unified, professional, and cohesive piece of work.
+- Sensors: We use touch sensors integrated into the handrails. Unlike traditional buttons, these respond to the natural grip passengers use to stabilize themselves.
-=== Structure ===
-Figures {{ref>fig:initial_drawing}}, {{ref>fig:final_drawings}} and {{ref>fig:final_final_drawings}} present all versions of structural drawings where each one has an incremental increase in quality and detail as project moved forward.
-<figure fig:initial_drawing>
+- LED Integration: RGB LED strips are installed along the connections of the handles and distributed across the ceiling panels. If necessary, a screen may also be mounted on the ceiling of the metro car to provide additional possibilities beyond the light strips, such as creating a changing environment with lighting adapted to the time of day. The placement and structure of the LEDs are clear and organized, allowing passengers to follow “their light” and trace the connection to other people.
-{{ :report:page_1.png?nolink | Initial drawing}}
-<caption>Initial structural drawing</caption>
-</figure>
-<figure fig:final_drawings>
-{{ :report:final_drawing.png?nolink  | Intermediate drawing}}
-<caption>Intermediate structural drawing</caption>
-</figure>
-<figure fig:final_final_drawings>
-{{ :report:final_drawing_v3.png?nolink | Final drawing}}
-<caption>Final structural drawing</caption>
-</figure>
-The completion of the structural drawings (see Figure {{ref>fig:final_drawings}}) marked a critical milestone, enabling the transition from conceptual frameworks to a specialized Bill of Materials (BoM), as detailed in Table {{ref>tab:components_ideal}}. This selection establishes the Connect and share system as a commercial-grade implementation in which safety and reliability are non-negotiable requirements. Three primary technical challenges shaped the component selection process: enclosure material and regulatory compliance, communication protocol and signal integrity, and power supply management.
+Tables {{ref>powerbudget1}} and {{ref>powerbudget2}} presents a electricity consumption of our hardware. Usage of interrupt based architecture and deep sleep modes decreases power consumption of installation significantly when not used, which helps to keep the system sustainable.
+<table powerbudget1>
+<caption>Power budget table (typical usage)</caption>
+<WRAP center round box 1100px>
+^ Equipment ^  Qty ^  Rail ^  U (V) ^  I per unit (A) ^  I total (A) ^  P (W) ^
+| ESP32-C3 sensor nodes |  10 |  5.0 V|  5 |  0.120 |  1.200 |  6.000 |
+| ESP32-C3 central node |  1 |  5.0 V|  5 |  0.150 |  0.150 |  0.750 |
+| CAN transceiver MCP2551 |  10 |  5.0 V|  5 |  0.010 |  0.100 |  0.500 |
+| LED strips WS2812B (2 m, 120 LEDs each) |  3 |  12.0 V |  12 |  2.400 |  7.200 |  86.400 |
+| Velostat pressure sensors |  15 |  3.3 V |  3.3 |  0.001 |  0.015 |  0.050 |
+| **Total** | | | | | |  **93.700** |
+| **Total + 25 % safety margin** | | | | | |  **117.125** |
+</WRAP>
+</table>
-*  I. Enclosure Material and Regulatory Compliance --
+<table powerbudget2>
-The overarching objective of this phase was to advance beyond laboratory prototypes toward a system fully compliant with rigorous European Union regulations, most critically EN 45545-2, which governs fire protection on railway vehicles. The initial proposal to use standard PLA for enclosures was rejected early in the design process due to its significant fire hazard profile. The design therefore transitioned to a PA Rail (Polyamide) enclosure, a material specifically engineered for railway environments that meets the low-smoke and flame-retardant benchmarks required for operation within subterranean metro infrastructures. Procuring infrastructure-grade hardware proved non-trivial, particularly for the rail-certified housing units, which required engagement with specialized international suppliers. This process exposed a significant technical disparity between consumer-grade components and the certified equipment essential for integration into public transit systems.
+<caption>Power budget table (peak usage)</caption>
+<WRAP center round box 1100px>
+^ Equipment ^  Qty ^  Rail ^  U (V) ^  I per unit (A) ^  I total (A) ^  P (W) ^
+| ESP32-C3 sensor nodes |  10 |  5.0 V |  5 |  0.300 |  3.000 |  15.000 |
+| ESP32-C3 central node |  1 |  5.0 V |  5 |  0.300 |  0.300 |  1.500 |
+| CAN transceiver MCP2551 |  10 |  5.0 V |  5 |  0.010 |  0.100 |  0.500 |
+| LED strips WS2812B (2 m, 120 LEDs each) |  3 |  12 V |  12 |  7.200 |  21.600 |  259.200 |
+| Velostat pressure sensors |  15 |  3.3 V |  3.3 |  0.001 |  0.015 |  0.050 |
+| **Total** | | | | | |  **276.250** |
+| **Total + 25 % safety margin** | | | | | |  **345.313** |
+</WRAP>
+</table>
+The hardware implementation is realized through two dedicated PCB designs: the Sensor Node PCB and the Central Node PCB.
-* II. Communication Protocol and Signal Integrity --
+**1. Sensor Node PCB**
-Metro carriages constitute high-interference electrical environments. High-voltage overhead conductors and traction motors generate substantial Electromagnetic Interference (EMI), which can readily corrupt standard data signals, making protocol selection a critical design decision. The Controller Area Network (CAN) protocol, implemented via the MCP2551 transceiver, was chosen for its inherent use of differential signaling, which provides strong immunity to common-mode noise. This architecture allows the Connect and share system to reject the electrical noise that routinely causes I²C or USB communications to fail in comparable environments. As a direct result, the system achieves stable data transmission between the handrail sensors and the ceiling LEDs even during periods of peak motor acceleration, which represents the most demanding electromagnetic conditions in regular operation.
+The Sensor Node PCB integrates all the components required for local sensing, processing, and communication. To convert physical pressure into data, the circuit utilizes a Velostat sensing interface in a voltage divider configuration. The detailed electrical connections are illustrated in the Sensor Node Schematic (Figure {{ref>fig:sensor_schematic}}).
-* III. Power Supply Management --
+<WRAP centeralign>
-To address the fluctuating power supply characteristics inherent to rolling stock, an industrial Mean Well DC-DC converter was integrated into the design. Beyond voltage stabilization, this component fulfills a second critical function: it provides regulated outputs at the multiple voltage levels required by the system's heterogeneous hardware, supplying 12 V to the LED strips and 5 V to the microcontrollers, thereby ensuring reliable and consistent operation across all subsystems.
+<figure fig:sensor_schematic>
+{{ :report:EPS-velostat-schematicV3.svg?direct&600 |}}
+<caption>Sensor Node Schematic Diagram</caption>
+</figure>
+</WRAP>
-<WRAP center round box 1100px>
+The node includes an ESP32-C3 Microcontroller (Wemos C3 Mini) and an MCP2551 CAN Transceiver. A 10kΩ potentiometer is included to allow manual calibration of the sensor's sensitivity range. As shown in Figure {{ref>fig:sensor_node_pcb}}, the PCB is designed to be embedded directly into the handrail structure for minimal visual impact and high mechanical robustness.
-<table tab:components_ideal>
-<caption>List of components for the product</caption>
+<WRAP centeralign>
-^ Name ^ Type ^ Supplier & more details ^ Additional notes ^ Price (€) ^ Quantity ^ Total (€) ^
+<figure fig:sensor_node_pcb>
-| Microcontroller | Wemos C3 mini | [[https://mauser.pt/095-1308/seeed-113991054-microcontrolador-seeed-studio-xiao-esp32c3-c-wi-fi-bluetooth-5-0-e-carregamento-de-bateria|Link]] | 1 is main board, others are support ones | 6,20 | 11 | 68,20 |
+{{ :report:sensor_node_pcb.png?direct&400 |}}
-| Box for electronics equipment | PA Rail | [[https://nanovia.tech/en/ref/nanovia-pa-rail/|Link]] | Fire resistant, could not find a portuguese supplier (this one is french) | 69,30 | 2 | 138,60 |
+<caption>Sensor Node PCB Layout</caption>
-| Copper tape |  | [[https://mauser.pt/095-6889/fita-condutora-de-cobre-adesiva-20mm-20m|Link]] |  | 8,86 | 15 | 132,90 |
+</figure>
-| Pressure sensor | Velostat | [[https://mauser.pt/096-9473/adafruit-1361-folha-de-velostat-piezoresistiva-p-sensores-de-pressao-wearable|Link]] |  | 7,90 | 15 | 118,50 |
-| CAN Transceiver | MCP2551-I-P | [[https://mauser.pt/001-1903/circuito-integrado-mcp2551-i-sn|Link]] | At 26.03 not in stock, email store to check availability | 1,99 | 10 | 19,90 |
-| LED strip with covers | Addressable RGB | [[https://www.amazon.es/dp/B01CNL6K52/ref=asc_df_B01CNL6K52?mcid=2fed6cd8fc303e129f0f7bf9a7df3d53&language=pt_PT&tag=ptgogshpadde-21&linkCode=df0&hvadid=718274527647&hvpos=&hvnetw=g&hvrand=10431677883703446528&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9218545&hvtargid=pla-408656678064&gad_source=1&th=1|Link]] |  | 30,49 | 3 | 91,47 |
-| Power supply (12 V) | DC-DC converter | [[https://www.worten.pt/produtos/modulo-conversor-dc-step-down-36v-72v-para-12v-10a-120w-regulador-de-voltaje-fuente-de-alimentacion-mrkean-5046628495403|Link]] | 2m strips draw 7.2 A at full power (~30 % reserve) | 24,67 | 6 | 148,02 |
-| Power supply (5 V) | DC-DC converter | [[https://www.worten.pt/produtos/modulo-conversor-dc-72v-para-5v-25a-75w-regulador-de-voltaje-com-caixa-de-aluminio-conversao-buck-mrkean-5046628823572|Link]] |  | 37,15 | 1 | 37,15 |
-| Wiring, resistors etc. |  | [[https://mauser.pt/104-7036/resistencia-de-filme-metalico-1kr-0-6w-1-2-5x6-8mm|Link]] | Really cheap | 10,00 | 1 | 10,00 |
-| Delivery cost |  | Stationary store | To be reviewed | 0 | 1 | 0 |
-| Total Project Cost |  |  |  |  |  | 764,74 |
-</table>
 </WRAP>
-(//iv//) 3D model with load and stress analysis;
-(//v//) colour palette.
+Each Sensor Node PCB operates as an autonomous unit within the distributed system, transmitting processed sensor data through the CAN bus network to the Central Node.
-=== Smart System ===
+**2. Central Node PCB**
+The Central Node PCB acts as the main coordination unit. It is responsible for aggregating data from all sensor nodes and generating the corresponding visual output. The integration of the processing unit with the lighting infrastructure is detailed in the Central Node Schematic (Figure {{ref>fig:central_schematic}}).
-== Hardware ==
+<WRAP centeralign>
+<figure fig:central_schematic>
+{{ :report:eps-leds-schematicv3.svg?direct&600 |}}
+<caption>Central Node Schematic Diagram</caption>
+</figure>
+</WRAP>
-Figure {{ref>fig:black_box_diagram}} presents the black box diagram, which includes all the major systems that will be used for our Smart System.
+As shown in Figure {{ref>fig:central_node_pcb}}, this PCB consolidates communication and actuation. It features a dedicated WS2812B LED Control port with a 330Ω resistor (R1) in series to protect the data line and ensure signal integrity.
 <WRAP centeralign>
-<figure fig:black_box_diagram>
+<figure fig:central_node_pcb>
-{{ :report:black-box-diagram.png?nolink | **Black Box Diagram**}}
+{{ :report:central_node_pcb.png?direct&400 |}}
-<caption>Black Box Diagram</caption>
+<caption>Central Node PCB Layout</caption>
 </figure>
 </WRAP>
+This board processes all incoming CAN messages and translates them into real-time visual feedback through the LED infrastructure, ensuring synchronization between multiple sensor inputs.
-- Sensors: We use touch sensors integrated into the handrails. Unlike traditional buttons, these respond to the natural grip passengers use to stabilize themselves.
+**Technical Implementation Details**
-- LED Integration: RGB LED strips are installed along the connections of the handles and distributed across the ceiling panels. If necessary, a screen may also be mounted on the ceiling of the metro car to provide additional possibilities beyond the light strips, such as creating a changing environment with lighting adapted to the time of day. The placement and structure of the LEDs are clear and organized, allowing passengers to follow “their light” and trace the connection to other people.
+A critical aspect of the design is the voltage compatibility between the ESP32-C3 (3.3V) and the MCP2551 (5V). While the transceiver requires 5V to meet CAN standards, the ESP32-C3 GPIOs are not 5V tolerant. To address this, both schematics implement a voltage divider on the RX line, using a 1kΩ resistor in series and a 2kΩ resistor to ground. This scales the signal from the MCP2551 down to approximately 3.3V, ensuring safe operation. The TX line is driven directly at 3.3V, which the MCP2551 identifies as a valid logic "high."
-Table {{ref>powerbudget}} presents a electricity consumption of our hardware. Usage of interrupt based architecture and deep sleep modes decreases power consumption of installation significantly when not used, which helps to keep the system sustainable
+To ensure reliable data transmission within the electromagnetically noisy environment of a metro car, the system employs:
-<WRAP center round box 1100px>
+  *Differential Signaling: Utilizing CAN High and CAN Low lines for high immunity to interference.
-<table powerbudget>
-<caption>Power budget table</caption>
+  *Bus Termination: A 120Ω resistor is placed across the CAN lines (as seen in the schematics) to match characteristic impedance and prevent signal reflections.
-^ Equipment ^ State ^ Qty ^ Rail ^ V (V) ^ I per unit (A) ^ Duty (%) ^ I<sub>eff</sub> total (A) ^ P<sub>eff</sub> (W) ^
-| ESP32-C3 sensor nodes | active | 10 | 5 V | 5 | 0.500000 | 53.3 | 2.665000 | 13.3250 |
-| ::: | sleep | 10 | 5 V | 5 | 0.000005 | 46.7 | 0.0000234 | 0.00012 |
-| ESP32-C3 actuator node | active | 1 | 5 V | 5 | 0.500000 | 53.3 | 0.266500 | 1.3325 |
-| ::: | sleep | 1 | 5 V | 5 | 0.000005 | 46.7 | 0.0000023 | 0.000012 |
-| CAN transceiver MCP2551 | active | 10 | 5V | 5 | 0.075000 | 53.3 | 0.399750 | 1.9988 |
-| ::: | sleep | 10 | 5 V | 5 | 0.001000 | 46.7 | 0.004670 | 0.02335 |
-| LED strip RGB (2m each) | active | 3 | 12 V | 12 | 7.200000 | 53.3 | 11.5128 | 138.154 |
-| ::: | sleep | 3 | 12 V | 12 | 0.000000 | 46.7 | 0.000000 | 0.0000 |
-| Velostat pressure sensors | active | 15 | 3.3 V | 3.3 | 0.003300 | 53.3 | 0.026384 | 0.08707 |
-| ::: | sleep | 15 | 3.3 V | 3.3 | 0.000000 | 46.7 | 0.000000 | 0.00000 |
-| **Total 5 V rail (effective)** | | | | | | | | **16.6901** |
-| **Total 12 V rail (effective)** | | | | | | | | **138.154** |
-| **Total 3.3 V rail (effective)** | | | | | | | | **0.0871** |
-| **Grand total (effective, duty-weighted)** | | | | | | | | **154.931** |
-| **Grand total (peak, all active simultaneously)** | | | | | | | | **809.01** |
-</table>
-</WRAP>
-== Software ==
+**Software**
 The software architecture of the Connect and Share project facilitates real-time interaction and asynchronous digital connection across two distinct modes of use.
@@ Line 241: / Line 277: @@
 Platform selection (see Table {{ref>tab:tech_stack}}) was guided by two priorities: low-latency hardware control and cross-platform accessibility.
-<WRAP center round box 800px>
 <table tab:tech_stack>
 <caption>Selection of tech stack</caption>
+<WRAP center round box 800px>
 ^ Layer ^ Selection ^ Justification ^
 | Firmware | ESP32 (C++) | Superior task management and precise control over LED timing. |
@@ Line 249: / Line 285: @@
 | Backend | Supabase | Relational data management and real-time database subscriptions. |
 | IoT Communication | CAN Bus | High noise immunity in metro environments via differential signaling. |
-</table>
 </WRAP>
+</table>
 III. Component Diagram
@@ Line 256: / Line 292: @@
 Figure {{ref>fig:frontend_flowchart}} depicts the frontend flow of the Connect web interface. Starting from a QR code scan, the browser fetches and renders the website. The user is then presented with two interaction options: writing a message, which is transmitted to the backend, or reading a message, which triggers a random message fetch and displays it on screen.
-<WRAP center>
+<WRAP centeralign>
 <figure fig:frontend_flowchart>
 {{ :report:flowchart_web_1_.png?nolink&600 | Frontend flow}}
@@ Line 263: / Line 299: @@
 </WRAP>
-Figure {{ref>fig:backend_flowchart}} illustrates the backend flow. Incoming HTTP requests are routed based on method: GET requests retrieve a randomly selected stored message and return HTTP 200, while POST requests pass the submitted content through an ML/AI moderation check. Content flagged as harmful is rejected with HTTP 400; clean content is saved to the database and confirmed with HTTP 200.
+Figure {{ref>fig:backend_flowchart}} illustrates the backend flow. IIncoming Hypertext Transfer Protocol (HTTP) requests are routed based on method: GET requests retrieve a randomly selected stored message and return HTTP 200, while POST requests pass the submitted content through a Machine Learning (ML) / Artificial Intelligence (AI) moderation check. Content flagged as harmful is rejected with HTTP 400; clean content is saved to the database and confirmed with HTTP 200.
-<WRAP center>
+<WRAP centeralign>
 <figure fig:backend_flowchart>
 {{ :report:flowchart_web_2_.png?nolink&600 | Backend flow}}
@@ Line 274: / Line 310: @@
 Figure {{ref>fig:iot_flowchart}} shows the firmware logic running on the two ESP32-C3 nodes. The upper flow covers the sensor node: it enters deep sleep after setup and wakes on a touch interrupt, transmits the event over CAN bus, then resets and loops. The lower flow covers the actuator node: it similarly sleeps until a CAN bus data frame is received, drives the LED strip, and resets. Both nodes share the same interrupt-driven sleep cycle structure.
-<WRAP center>
+<WRAP centeralign>
 <figure fig:iot_flowchart>
 {{ :report:flowchart-iot.png?nolink&600 | Flowchart IoT}}
@@ Line 280: / Line 316: @@
 </figure>
 </WRAP>
-=== Packaging ===
+=== 7.4.3 Packaging ===
 Present and explain the:
 (//i//) initial packaging drafts;
 (//i//i) detailed drawings;
 (//iii//) 3D model with load and stress analysis, if applicable.
-==== Prototype ====
+==== 7.5 Prototype ====
 Refer main changes in relation to the designed solution.
@@ Line 314: / Line 350: @@
 ^ ID ^ Category ^ Requirement / Description ^ Success Criteria ^ Status ^ Date ^
 | FT-01 | Functionality | Velostat Touch Detection | ADC values respond linearly to pressure | | |
-| FT-02 | Functionality | CAN Bus Communication | Packet Delivery Ratio > 99.9% | | |
+| FT-02 | Functionality | CAN Bus Communication | Packet Delivery Ratio > 99.9 % | | |
 | FT-03 | Functionality | LED Visual Response | Correct RGB colors and no flickering | | |
 | FT-04 | Functionality | Sensitivity Calibration | Potentiometer adjusts trigger threshold | | |
-| FT-05 | Functionality | Power Management | Stable 5.0V output at 72V/110V input | | |
+| FT-05 | Functionality | Power Management | Stable 5.0 V output at 72 V/110 V input | | |
-| PT-01 | Performance | System Response Time | Total latency from touch to light < 100ms | | |
+| PT-01 | Performance | System Response Time | Total latency from touch to light < 100 ms | | |
 | PT-02 | Performance | EMI Noise Resistance | No "ghost triggers" near DC motors | | |
-| PT-03 | Performance | Thermal Performance | Enclosure surface temp < 50°C after 4h | | |
+| PT-03 | Performance | Thermal Performance | Enclosure surface temp < 50 °C after 4 h | | |
-| PT-04 | Performance | Voltage Drop | End-of-line voltage > 4.7V | | |
+| PT-04 | Performance | Voltage Drop | End-of-line voltage > 4.7 V | | |
-| PT-05 | Performance | Long-term Durability | System stable after 1,000 trigger cycles | | |
+| PT-05 | Performance | Long-term Durability | System stable after 1000 trigger cycles | | |
 | ST-01 | Software | Integration Simulation | Zero mechanical interference in CAD model | | |
 | ST-02 | Software | CAN Logic Simulation | Correct ID priority during collisions | | |
@@ Line 330: / Line 366: @@
 | SF-02 | Safety | Mechanical Safety | No sharp edges/protruding screws (Tactile) | | |
 | SF-03 | Safety | Fire Safety | Cables/Plastic certified V-0 or LSHF | | |
-| SF-04 | Safety | Vandalism Resistance | Sensor functional after 5kg impact test | | |
+| SF-04 | Safety | Vandalism Resistance | Sensor functional after 5 kg impact test | | |
 | SF-05 | Safety | Ingress Protection (IP) | No moisture inside after cleaning mist test | | |
 | UA-01 | UAT | Trigger Intuitiveness | User finds sensor without instructions | | |
@@ Line 346: / Line 382: @@
 (iii) usability tests according to the [[https://www.usability.gov/how-to-and-tools/methods/system-usability-scale.html|System Usability Scale]].
-==== Summary ====
+==== 7.6 Summary ====
-//Provide here the conclusions of this chapter and make the bridge to the next chapter.//
+This chapter documents the comprehensive lifecycle of the Connect project, tracing its evolution from initial conceptualization to a fully realized and validated prototype. The development process was driven by the goal of transforming a standard metro carriage into a collaborative, interactive canvas designed to counteract digital isolation.
+The phase began with Ideation and Design, where the core problem of digital passivity was translated into a two-phase interactive solution: real-time ambient light tracking and asynchronous voice messaging. This conceptual foundation was supported by a Smart System architecture, integrating touch-sensitive hardware with custom color-blending algorithms.
+To move from theory to reality, the Structure stage utilized detailed 3D modeling and analysis to ensure physical viability. Iterative adjustments were made to hardware schematics and software flowcharts to optimize performance.
+Having detailed the technical execution and rigorous testing of the system, the following section synthesizes these results to provide final reflections on the project's impact and future potential.