Vacuum Robot Component Connection Diagram

October 30, 2025 · View on GitHub

This diagram shows all hardware components and their connections. Each connection references evidence documented in Connection_Evidence.md.

Legend:

  • ✅ PROVEN - Confirmed through testing/analysis
  • 🔍 LIKELY - Strong evidence, needs final confirmation
  • ❓ HYPOTHESIS - Logical assumption, needs testing
  • Solid lines (---) - Proven connections
  • Dashed lines (-.-) - Likely but unconfirmed connections
  • Dotted lines (···) - Hypothetical connections

System Architecture Diagram

graph TB
    %% Main processors
    A33[Allwinner A33<br/>ARM Cortex-A7<br/>Quad-Core]
    GD32[GigaDevice GD32F103VCT6<br/>ARM Cortex-M3<br/>108MHz]

    %% Navigation
    LIDAR[Lidar Sensor<br/>3irobotix Delta-2D<br/>J17]

    %% Motors and drivers
    LMOTOR[Left Wheel Motor<br/>J24]
    RMOTOR[Right Wheel Motor<br/>J27]
    BRUSH[Rolling Brush<br/>J15]
    VACUUM[Vacuum Pump<br/>J16]
    SWEEP[Sweeper Motor<br/>J26]

    %% Sensors - Safety Critical
    LENC[Left Wheel Encoder<br/>J25]
    RENC[Right Wheel Encoder<br/>J26]
    FCLIFF[Front Cliff Sensors<br/>IR L&R<br/>J5]
    LCLIFF[Left Cliff Sensor<br/>J25]
    RCLIFF[Right Cliff Sensor<br/>J26]
    LBUMP[Left Bumper<br/>J25]
    RBUMP[Right Bumper<br/>J26]

    %% Sensors - Status
    DUST[Dust Box Sensor<br/>J48]
    WATER[Water Box Sensor<br/>J48]
    MOP[Mop Pad Sensor<br/>J34]

    %% User Interface
    BTNS[Buttons<br/>Power/Home/Clean]
    SPEAK[Speaker<br/>J18]

    %% === A33 TO GD32 CONNECTIONS ===
    A33 ---|✅ UART3 TX<br/>PH6→PA10<br/>115200 baud<br/>Ref: E1| GD32
    GD32 -.-|❌ UART3 RX<br/>PA9→PH7<br/>UNUSED<br/>Ref: E2| A33
    A33 ---|🔍 GPIO<br/>PH9 gpio-233<br/>Reset/Boot?<br/>Ref: E3| GD32
    A33 -.-|🔍 GPIO<br/>PD11 gpio-107<br/>Enable?<br/>Ref: E4| GD32
    GD32 -.-|🔍 GPIO<br/>?→PB7 gpio-39<br/>Status<br/>Ref: E5| A33

    %% === A33 DIRECT CONNECTIONS ===
    A33 <===|✅ UART1<br/>PG6/PG7<br/>115200 baud<br/>Ref: E6| LIDAR
    A33 -.->|❓ GPIO/ADC<br/>Ref: E10| DUST
    A33 -.->|❓ GPIO<br/>Ref: E11| WATER
    A33 -.->|❓ GPIO<br/>Ref: E12| MOP
    A33 -.->|❓ GPIO<br/>Ref: E13| BTNS
    A33 --->|❓ I2S/PWM<br/>Ref: E14| SPEAK

    %% === GD32 CONNECTIONS - MOTORS ===
    GD32 -.->|❓ PWM<br/>Ref: E8| LMOTOR
    GD32 -.->|❓ PWM<br/>Ref: E8| RMOTOR
    GD32 -.->|❓ PWM<br/>Ref: E8| BRUSH
    GD32 -.->|❓ PWM<br/>Ref: E8| VACUUM
    GD32 -.->|❓ GPIO/PWM<br/>Ref: E8| SWEEP

    %% === GD32 CONNECTIONS - ENCODERS ===
    GD32 <-.-|❓ Timer Input<br/>Quadrature<br/>Ref: E7| LENC
    GD32 <-.-|❓ Timer Input<br/>Quadrature<br/>Ref: E7| RENC

    %% === GD32 CONNECTIONS - SAFETY SENSORS ===
    GD32 <-.-|❓ ADC/GPIO<br/>Safety Critical<br/>Ref: E9| FCLIFF
    GD32 <-.-|❓ ADC/GPIO<br/>Ref: E9| LCLIFF
    GD32 <-.-|❓ ADC/GPIO<br/>Ref: E9| RCLIFF
    GD32 <-.-|❓ GPIO<br/>Interrupt<br/>Ref: E9| LBUMP
    GD32 <-.-|❓ GPIO<br/>Interrupt<br/>Ref: E9| RBUMP

    %% Styling
    classDef proven fill:#90EE90,stroke:#006400,stroke-width:3px
    classDef likely fill:#FFD700,stroke:#FF8C00,stroke-width:2px
    classDef hypothesis fill:#87CEEB,stroke:#4682B4,stroke-width:1px
    classDef processor fill:#DDA0DD,stroke:#8B008B,stroke-width:3px

    class A33,GD32 processor

Communication Protocols Detail

✅ PROVEN Connections

A33 → GD32: UART3 Command Channel

  • Protocol: Custom binary protocol
  • Baud: 115200, 8N1, no flow control
  • Format: FA FB LENGTH CMD DATA[0..N] CRC
  • Direction: ONE-WAY (A33 sends only)
  • Commands Known:
    • 0x06: Heartbeat
    • 0x0D: Status request
    • 0x66: Initialization/control (11 bytes payload)
  • Evidence: [E1] in Connection_Evidence.md

A33 ↔ Lidar: UART1 Bidirectional

  • Protocol: 3irobotix proprietary
  • Baud: 115200, 8N1, hardware flow control
  • Format: 8-byte header + variable payload
  • Commands:
    • 0xAE: Health status query
    • 0xAD: Measurement data
  • Working: Yes, tested with scan.py
  • Evidence: [E6] in Connection_Evidence.md

🔍 LIKELY Connections

A33 → GD32: Control GPIOs

  • gpio-233 (PH9): Reset or Boot mode control (OUTPUT, HIGH)
  • gpio-107 (PD11): Enable or power control (OUTPUT, HIGH)
  • Evidence: [E3, E4] in Connection_Evidence.md

GD32 → A33: Status GPIO

  • gpio-39 (PB7): Status line (INPUT, currently LOW)
  • Possible meanings:
    • LOW = Ready, HIGH = Obstacle detected
    • Or inverted: LOW = Obstacle, HIGH = Ready
  • Evidence: [E5] in Connection_Evidence.md

❓ HYPOTHESIS Connections

All GD32 sensor connections are hypothetical based on:

  • Connector documentation
  • Standard motor control requirements
  • Safety-critical system design
  • GD32 peripheral capabilities

These need:

  • Physical connector pinout analysis
  • PCB tracing
  • Runtime testing
  • Oscilloscope/logic analyzer capture

Connector Pinout Summary

J17 - Lidar (5-pin, 2mm PH)

PinFunctionDirectionNotes
1Motor+Power5V for rotation
2Motor-PowerGND
3TXOutputLidar → A33 PG7 (UART1_RX)
4RXInputA33 PG6 (UART1_TX) → Lidar
5GNDPowerGround

Status: ✅ PROVEN through scan.py testing

J25 - Left Wheel (16-pin, 1mm SHD)

Contains:

  • Left wheel encoder (2-4 pins for A/B channels)
  • Dustbox power (2 pins)
  • Left side fall detect IR (2-3 pins)
  • Left hit detect sensor (1-2 pins)

Status: ❓ HYPOTHESIS - needs pinout analysis

J26 - Right Wheel (16-pin, 1mm SHD)

Contains:

  • Right wheel encoder (2-4 pins)
  • Sweeper motor power (2 pins)
  • Right side fall detect IR (2-3 pins)
  • Right hit detect sensor (1-2 pins)

Status: ❓ HYPOTHESIS - needs pinout analysis

Other Connectors

See README.md for complete connector list.

Evidence Reference Map

RefConnectionStatusEvidence File Section
E1A33 UART3_TX→GD32✅ PROVEN"A33 → GD32 UART"
E2A33 UART3_RX←GD32❌ UNUSED"A33 ← GD32 UART_RX"
E3A33 gpio-233→GD32🔍 LIKELY"A33 → GD32 Control GPIO"
E4A33 gpio-107→GD32🔍 LIKELY"A33 → GD32 Enable GPIO"
E5A33 gpio-39←GD32🔍 LIKELY"A33 ← GD32 Status GPIO"
E6A33 UART1↔Lidar✅ PROVEN"A33 → Lidar Sensor"
E7GD32←Encoders❓ HYPOTHESIS"GD32 ← Motor Encoders"
E8GD32→Motors❓ HYPOTHESIS"GD32 → Motor Drivers"
E9GD32←Cliff/Bumper❓ HYPOTHESIS"GD32 ← Cliff Sensors"
E10A33←Dust Box❓ HYPOTHESIS"A33 ← Dust Box Sensor"
E11A33←Water Box❓ HYPOTHESIS"A33 ← Water Box Detector"
E12A33←Mop Pad❓ HYPOTHESIS"A33 ← Mop Pad Sensor"
E13A33←Buttons❓ HYPOTHESIS"A33 ← Buttons"
E14A33→Speaker❓ HYPOTHESIS"A33 → Speaker"

Next Steps for Verification

High Priority Tests (Can do now):

  1. Monitor gpio-39 during robot operation

    watch -n 0.1 'cat /sys/class/gpio/gpio39/value'

  2. Test gpio-233 toggle to see GD32 response

    echo 0 > /sys/class/gpio/gpio233/value
sleep 1
echo 1 > /sys/class/gpio/gpio233/value

  3. Verify Lidar (already working but document)

    dd if=/dev/ttyS1 bs=1 count=1000 | hexdump -C

Medium Priority (Needs physical access):

  1. Probe J25/J26 pins with oscilloscope during operation
  2. Use multimeter continuity to trace PCB connections
  3. Measure voltage levels at connector pins

Low Priority (Deep dive):

  1. Disassemble and probe individual sensors
  2. Reverse engineer complete connector pinouts
  3. Capture GD32 firmware for detailed analysis

Updates Log

DateUpdateEvidence Added
2025-10-28Initial diagram creationE1-E6 documented
Added power connectionsStandard design
Added hypothetical sensor connectionsE7-E13 placeholders

Note: This is a living document. As we test and verify each connection, the diagram will be updated with proven connections replacing hypothetical ones. Always check Connection_Evidence.md for the latest test results and evidence.