M8T1:Assemble Final Hardware Prototype

[Hisham4Ahmed]

M8T1:Assemble Final Hardware Prototype

1. Summary

This task focuses on assembling the complete physical prototype of the Smart Air Quality Monitor using the finalized PCB and all hardware components.
The goal is to build a fully functional, enclosure-ready hardware unit identical to what will be delivered to the client.
This is the transition from “engineering design” → physical product .

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2. Goal / Deliverables

At the end of this task, the team should have:

✔️ Fully assembled hardware prototype including

• Custom PCB (from Milestone 7)
• All sensors soldered & mounted
  • MQ135
  • BME680
  • PMS5003 (if advanced version)
  • DHT22
• Actuators
  • Buzzer
  • LED
• Display unit
  • LCD 16x4 or OLED 128x64 (based on config)
• Communication modules
  • HC-05
  • ESP-01
• Power supply module (regulators, USB, battery if applicable)

✔️ Functional wiring, soldering, headers, connectors

✔️ Physical assembly inside an enclosure (optional but recommended)

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3. Steps to Implement

Step 1 — Prepare Components & Tools

• Gather all components from the BOM (previous milestone).
• Prepare tools:
  • Soldering iron
  • Hot air station (optional)
  • Multimeter
  • Debug tools (USB-TTL, AVR programmer)
  • Screws, standoffs, jumpers, cables

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Step 2 — PCB Inspection (Pre-Solder Check)

• Visually inspect PCB fabrication quality:
  • Check traces
  • Check pads alignment
  • Check silkscreen correctness
  • Check no short-circuits between layers
• Verify component footprints match the actual hardware.

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Step 3 — Soldering Components

Order of soldering should be:

1. Small passive components

   (resistors, capacitors, pull-ups, etc.)

2. ICs & sockets

   • ESP-01 header
   • HC-05 header
   • EEPROM socket (if used)
   • Voltage regulators

3. Connectors & headers

   • UART header
   • I2C header
   • ISP/AVR programmer header

4. Sensors

   • Fix PMS5003 connector
   • Mount MQ135
   • Mount DHT22
   • Mount BME680 module

5. Displays

   • OLED I2C header
   • LCD 4-bit header

6. Actuators

   • Buzzer
   • LED + resistor

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Step 4 — Power Verification

Before powering the board fully:

• Use multimeter to check:
  • VCC–GND continuity
  • No shorts
  • Regulator output is correct (e.g., 5V, 3.3V)
• Power the board with limited current (bench supply).

If voltage rails are stable → proceed.

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Step 5 — Mount MCU + Flash Bootloader

• Insert ATmega32 (if socketed).
• Connect AVR programmer.
• Flash bootloader / minimal firmware.
• Verify:
  • MCU draws expected current.
  • Clock source works (crystal or internal).

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Step 6 — Verify Communication Modules

• Test ESP-01 power and UART pins.
• Test HC-05 pairing and serial link.
• Test I2C bus for OLED + BME680.
• Test UART link for PMS5003.

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Step 7 — Full Assembly in Enclosure

(Optional but preferred for final prototype)

• 3D print or laser-cut enclosure.
• Mount PCB with standoffs.
• Mount sensors with airflow access.
• Add display window.
• Add power input connector.

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4. Dependencies

This task depends on finishing:

• ✔️ M7 (PCB layout, fabrication, BOM)
• ✔️ MCAL drivers (esp. UART, I2C)
• ✔️ HAL drivers (display, sensors)
• ✔️ ESP-01 firmware

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5. Acceptance Criteria

Prototype is accepted when:

• Board powers ON successfully.
• No shorts or overheating.
• MCU boots consistently.
• All sensors respond over their respective interfaces.
• Display shows initial boot screen.
• ESP-01 + HC-05 can communicate.
• Buzzer + LED respond to test patterns.
• Prototype is structurally stable (screws, enclosure).

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6. Definition of Done (DoD)

• PCB completely assembled and inspected.
• All components soldered and firmly mounted.
• Power system verified.
• Basic firmware flashed & board boots correctly.
• All interfaces (UART, I2C, ADC, GPIO) tested at hardware level.
• Photo documentation added to repository under /Hardware/Prototype.
• Prototype approved for final firmware flashing (next task).