IoT WSN → TinyOS → Cooja Simulation → Node-RED

An end-to-end IoT / WSN demo showing how to:

• simulate TinyOS TelosB (Sky) motes in Cooja
• forward sink data via Serial Socket → TCP
• parse TinyOS serial frames in Node-RED
• log and visualize sensor data (file logging, dweet/freeboard, Google Sheets)
• trigger alerts (email / tweet thresholds)

Architecture

[Temp Mote] --\
               \ (ActiveMessage RADIO_MSG=6)
                \
                 \                   (SerialActiveMessage SERIAL_MSG=0x89)
[Hum  Mote] -------> [Sink Mote] -----------------------------------------------> [Cooja Serial Socket :60003]
                                                                                              |
                                                                                              v
                                                                                        [Node-RED TCP IN]
                                                   |-----------------------------+------------------------------+-------------------------|
                                                   |                             |                              |                         |
                                            local log file                 dweet.io (realtime)           Google Form/Sheet             alerts
                                          sensorlog.txt (JSON)             freeboard dashboard          chart (last samples)         email/tweet

Scenario

The WSN consists of one Sink/Server node (PAN coordinator) and two sensor nodes (temperature and humidity).

1. Each sensor node boots, starts its radio, reads its sensor value, and sends a packet that includes:
   • a type ID (to distinguish temperature vs humidity)
   • the 16-bit sensor sample in the payload
2. The sink listens for incoming packets.
3. When the sink receives a packet, it checks the type ID and stores the value in the corresponding variable.
4. Once the sink has samples from both sensors, it packs them into a serial message and sends it to the PC.
5. In Cooja, the sink’s serial output is exposed via Serial Socket (TCP on localhost).
6. Node-RED listens on the same TCP port, parses the incoming TinyOS serial frames, and:
   • logs data to sensorlog.txt
   • optionally pushes data to cloud dashboards (Dweet/Freeboard, Google Sheets)
   • triggers alarms (email for high temperature, tweet for high humidity)

Repository Structure

• TinyOS/
  • Temp/ Temperature sensor node (broadcasts msg_type=1)
  • Hum/ Humidity sensor node (broadcasts msg_type=2)
  • Sink/ Sink node (receives both, forwards combined serial payload)
• Node-RED/flows.json Node-RED flow export (JSON)
• cooja/projectIoT.csc Cooja simulation configuration
• media/ project screenshots

How it Works (data formats)

Radio message (Temp/Hum → Sink)

Active Message type: RADIO_MSG = 6

Payload struct (radio):

typedef nx_struct mag_msg {
  nx_uint8_t  msg_type; // 1=temp, 2=hum
  nx_uint16_t data;     // raw 16-bit sample
} mag_msg_t;

Serial message (Sink → Node-RED)

Serial AM type: SERIAL_MSG = 0x89 (decimal 137)

Payload struct (serial):

typedef nx_struct mags_msg {
  nx_uint16_t datat; // temp raw
  nx_uint16_t datah; // hum raw
} mags_msg_t;

Node-RED parses TinyOS HDLC-framed serial packets (0x7E … 0x7E), extracts 4 payload bytes
(2 bytes temp + 2 bytes humidity), and scales them to 0–100.

Requirements

• A Linux environment with:
  • Cooja (Instant Contiki VM works)
  • TinyOS toolchain for TelosB / MSP430 (to build main.exe)
  • Node-RED
• Optional (for the “cloud” parts):
  • a Google Form connected to a Google Sheet (for logging/plotting)
  • dweet.io + freeboard.io dashboard

Build the TinyOS applications

From each TinyOS app folder, build for TelosB:

cd "TinyOS/Temp"
make telosb

cd "../Hum"
make telosb

cd "../Sink"
make telosb

This produces:

• build/telosb/main.exe in each directory

Run the Cooja simulation

1. Start Cooja.
2. Open the simulation:
   • File → Open simulation…
   • select cooja Simulation file/projectIoT.csc
3. Ensure each mote type points to the correct main.exe firmware.
4. Open the Serial Socket plugin:
   • Tools → Serial Socket
   • select the Sink mote (Sky 3 / ID 3)
   • choose Server mode
   • port: 60003
5. Start the simulation.

Run Node-RED

1. Start Node-RED:

   node-red

2. Open:
   • http://localhost:1880
3. Import the flow:
   • Menu (☰) → Import → Clipboard
   • paste the content of Node-RED/noderedflows
4. Update configuration:
   • tcp in node: host localhost, port 60003
   • file path for sensorlog.txt (default: ./sensorlog.txt)
   • (optional) configure:
     • Email node credentials
     • Twitter node credentials
     • Google Form URL / entry IDs
     • Dweet and Freeboard configuration
5. Deploy.

Screenshots

Project Diagram

Node-RED Flow

Cooja + Serial Socket

Freeboard realtime dashboard

Google chart

Notes / Customization

• Datasets
  • This project uses fixed datasets for simulation.
  • If you replace the datasets, ensure *_DATA_SIZE matches the number of values.
• Serial parsing in Node-RED
  • If you change the TinyOS serial payload size, you must update the parser accordingly.
• Port
  • If you change Serial Socket port in Cooja, also change Node-RED TCP IN port.
• Paths
  • Replace hard-coded paths with a path that exists on your system.

License

MIT License (see LICENSE).