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graph LR
A[Physical<br/>Phenomenon<br/>25.6°C] --> B[Sensor<br/>Element<br/>2.56V]
B --> C[ADC<br/>Conversion<br/>0x0A00]
C --> D[Processing<br/>Filtering<br/>25.6°C]
D --> E[Formatting<br/>JSON/CBOR<br/>payload]
E --> F[Network<br/>Packet<br/>Transmission]
style A fill:#E67E22,stroke:#16A085,stroke-width:2px,color:#fff
style B fill:#2C3E50,stroke:#16A085,stroke-width:2px,color:#fff
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style D fill:#2C3E50,stroke:#16A085,stroke-width:2px,color:#fff
style E fill:#16A085,stroke:#2C3E50,stroke-width:2px,color:#fff
style F fill:#E67E22,stroke:#2C3E50,stroke-width:2px,color:#fff
57 Sensor to Network Pipeline
57.1 Learning Objectives
By the end of this chapter series, you will be able to:
- Trace the Data Journey: Follow sensor data from physical measurement to network transmission
- Identify Pipeline Stages: Understand each transformation step from analog signal to network packet
- Design Data Pipelines: Create efficient sensor-to-network architectures for IoT applications
- Apply Signal Processing: Implement filtering, sampling, and conditioning techniques
- Optimize Transmission: Balance data quality, latency, and bandwidth in pipeline design
This topic has been split into three focused chapters for easier learning:
- Pipeline Overview and Signal Acquisition - Stages 1-3
- Complete pipeline architecture
- Physical measurement (Stage 1)
- Signal conditioning (Stage 2)
- ADC conversion (Stage 3)
- Processing and Formatting - Stages 4-6
- Digital processing and calibration (Stage 4)
- Data formatting: JSON, CBOR, binary (Stage 5)
- Packet assembly and protocol overhead (Stage 6)
- Transmission and Optimization - Stage 7 + Complete Journey
- Network transmission technologies (Stage 7)
- Complete sensor-to-cloud trace
- Latency and energy analysis
- Optimization strategies and design frameworks
57.2 The 7-Stage Pipeline
Every IoT sensor reading passes through exactly 7 transformation stages:
| Stage | Name | Input | Output | Covered In |
|---|---|---|---|---|
| 1 | Physical Measurement | Heat, light, pressure | Voltage/current | Overview |
| 2 | Signal Conditioning | Weak analog signal | Clean, scaled signal | Overview |
| 3 | ADC Conversion | Analog voltage | Digital binary value | Overview |
| 4 | Digital Processing | Raw ADC value | Calibrated measurement | Processing |
| 5 | Data Formatting | Numeric value | JSON/CBOR/binary | Processing |
| 6 | Packet Assembly | Formatted data | Protocol packet | Processing |
| 7 | Network Transmission | Complete packet | Radio waves | Transmission |
57.3 Key Takeaway
Network transmission typically dominates latency (60-70%) and energy consumption (80-90%) - so optimize for fewer transmissions (edge processing) and smaller payloads (binary formats) before optimizing local processing speed.
When a temperature sensor measures 25.6°C, that number doesn’t magically appear in a cloud database. It goes through a remarkable transformation journey:
- Physical World: Heat affects the sensor material
- Electrical Signal: Material change creates a voltage (e.g., 2.56V)
- Digital Number: ADC converts voltage to binary (0000101000000)
- Processed Value: Firmware calculates temperature = 25.6°C
- Formatted Data: Value becomes JSON:
{"temp": 25.6} - Network Packet: Data gets wrapped with headers for transmission
- Cloud Storage: Finally stored in a database
Simple Analogy: It’s like sending a letter. You write a message (sensor reading), put it in an envelope (data format), add an address and stamp (packet headers), and mail it (network transmission).