EnHantsBy: Shakhul Hai

Background

EnHants is an acronym for Energy-Harvesting Active Networked Tags

EnHants are small, flexible, and self reliant devices that can be attached to arbitrary objects that are not traditionally networked

-Examples: food, books, produce etc.

Goal of EnHants

Network- Actively Communicate with one another and with EnHant-friendly devices in order to forward information over a multihop network

Operate at ultra-low power- Spend a few nano-Joules or less on every transmitted bit

Harvest energy- Collect and store energy from sources such as light, motion, temperature gradients

Contd.

Are Energy Adaptive- Alter communications and networking to satisfy energy and harvesting constraints

Exchange small messages- Exchange limited information using low datas, possibly in several transmission bursts

Transmit to short ranges- communicate only when in proximity to one another

Are thin,flexible and small

Materials/Software

Microsoft Excel 2003/ Open Office Spreadsheet

Python Light Measurement Sensor

Light Sensor

What I Did

• My job was to do outdoor and indoor light measurements to see light conditions in different environments/locations.

Procedure

[command In order to start measurements] Python light.py –d –s 0.5 –t 60 –f test.dat

After collecting data, data was transferred over to Microsoft Excel/ Open Office Spreadsheet

Then converted into microwats - Conversion formula:

300Hz*0.1uW/Hz = 30 uW

Contd.

The highest and lowest 2 datas were removed

Average the data Make a graph of the data

Experiments

00.511.522.533.544.555.566.577.588.599.51010.51111.51212.51313.51414.51515.51616.51717.51818.51919.52020.52121.52222.52323.52424.52525.52626.52727.52828.52929.53030.53131.53232.53333.53434.53535.53636.53737.53838.53939.54040.54141.54242.54343.54444.54545.54646.54747.54848.54949.55050.55151.55252.55353.55454.55555.55656.55757.55858.55959.56060.56161.56262.56363.56464.56565.56666.56767.56868.56969.57070.57171.57272.57373.57474.57575.57676.57777.57878.57979.58080.58181.58282.58383.58484.58585.58686.58787.58888.58989.59090.59191.59292.59393.59494.59595.59696.59797.59898.59999.5

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35

light measurements

Measurements in the EE Conference Room

3 J/day on average

Shelf ‘map’ Gil’s office, facing South, 5 `racks’, 7

‘shelves’ Each spot measured with and without

the indoor lighting

Lights off

1.7878 1.4690 2.1793 2.1034 3.3724 1.5959 1.2690 1.8069 2.3793 3.2000 1.4163 1.2000 1.8138 2.4000 3.4966 0.7918 1.2207 1.7379 2.6483 4.1034 0.7020 1.0414 1.5793 2.6000 3.3034 0.8000 0.8966 1.2000 2.9862 2.2966 0.8000 0.8000 1.2000 2.0828 1.2621

uW/cm^2

Indoor light

9.0449 14.7793 15.0759 15.3104 14.4621 12.6082 24.9034 29.0069 28.2690 24.8759 20.1470 34.2000 36.4000 40.3034 31.6275 25.5429 36.4345 46.5724 44.6483 35.9242 24.0123 34.7103 43.2069 43.9034 34.5725 24.8857 32.6620 41.2966 39.5241 33.0344 22.2163 27.8776 35.6759 35.0138 30.4482

uW/cm^2

Future work

Further long-term data collection, analysis, use in simulations

References

Energy Harvesting Networked Tags (EnHants) Project, Columbia University, http://enhants.ee.columbia.edu

Acknowledgements

Mentor: Maria Gorlatova Professor Gil [head of the project] Columbia Electrical Engineering

Department Dr. Sat

THANK YOU