Earth Tones

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MANTIS System Support for Multi-modal Networks
of in-situ Sensors
Presented by Saswati Swami
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MANTIS Project Goals

• Offer a general-purpose software/hardware
  platform that
• Simplifies sensor networking for newcomers
• Preserves flexibility for advanced research
• Adapts to resource constraints
• Targets for streamlining
• Software API and OS
• Hardware Accessibility

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Lightweight MANTIS Operating System Design

• Simple C API
• Easy to program
• For advanced users
• Reuse code
• Cross-platform Portability
• Simple multithreading
• Familiar UNIX-like semantics
• For advanced users
• flexible time-sliced scheduling for complex apps

void adc_send() uint8_t value while(1)
value adc_read_8bit(ADC_CH_2)
mos_send_to(NODE2, PORT1, value, 1,
FLOODING)
Modest learning curve
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Multithreaded MANTIS OS (MOS)
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Lightweight MOS Kernel

• Multi-threaded
• Priority/round-robin scheduling
• Fast context switching
• Counting and binary semaphores
• 144 byte static RAM footprint
• 10-byte thread table entries
• Thread context saved on stack
• Stack space allocated dynamically

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Cross-Platform MANTIS OS
X86 PC
T3
T4
T5
MANTIS System API
POSIX Shim Layer
UNIX
X86 Hardware
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Cross-Platform User-level Network Stack

• Non-strict layered design
• Easy to modify/experiment
• Chained headers eliminate inter-layer
  copies
• Zero-copy on send, forward
• Zero- or single-copy on delivery to application

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Integrating Applications Into the Sensor Network
Is Easy

• Application, e.g.
• Visualization app
• Bridging Gateway

X Windows GUI
Socket API
Database API
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Multimodal Virtual/Physical Sensor Network
Virtual Sensor Network Of XMOS Nodes
Wireless Sensor Network Of AMOS Nodes
USB/ Serial
Visualization Application
Bridging XMOS Gateway
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Dynamic Reprogramming

• Reprogram entire node while deployed
• MOS boot loader can re-flash entire OS
• Load stored code image from EEPROM
• Source-independent reprogramming
• Standard API to store code image to EEPROM
• Reprogramming possible over arbitrary connection
  (multi-hop), or from application
• Simple, flexible network management

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Dynamic Reprogramming
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Remote Shell/Command Server

• Remote login to nodes
• Debugging functions
• Peek/poke
• Kernel status info
• Configuration
• Spawn threads
• Call functions
• Reprogram node

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Hardware Overview

• Same core as MICA 2
• CC1000 multi-channel radio
• ATMEGA 128 microcontroller
• Possible to install MOS on MICA 2 (minor port)
• Single board design
• Standard 3-wire sensor interface on-board
• On-board serial doubles as programming interface
• 20-pin expansion connector
• GPS port
• Multiple power options

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Sample Applications

• Rapid prototyping of user interface devices
• Conductors baton
• GPS enabled time-synchronization
• Use GPS clock to evaluate network
  time-synchronization protocols
• Demonstrated improvement using multi-channel
  protocol
• Robotic networks
• Nymph-controlled RC car

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Conclusion

• MANTIS system provides some new capability
• Lightweight, multithreaded, cross-platform OS and
  network
• Flexible single-board hardware platform
• Easily integrates sensor networks with other
  applications
• MANTIS is also user-friendly
• Familiar API and language
• Powerful management tools

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Thank You