Saturday, November 5, 2011

Lake Sensor Project: Bill of Materials

Hardware top level description:

This project consists of two main hardware assembles:
1) Sensor package attached to dock with wireless data transmission
2) Wireless data receiver module attached to PC

I used the Arduino because I had one on hand. This particular model isn't manufactured any longer, but any of the newer models should work fine.

There are all kinds of rube-goldberg ways to measure lake level. I felt an ultrasonic distance sensor would be a good way to measure the lake level with no mechanical complexity. They are also fairly cheap, particularly off of Ebay. The HC-SR04 didn't have great examples online on how to implement the code, but I used some code examples off of Adafruit's excellent website and modified them for the 4-pin HC-SR04 vs. the models Adafruit carries.

The other sensors are pretty self-explanatory, I chose them for a nice balance of price vs. accuracy.

I had a hard time deciding whether to go with wireless data transmission, or wired. There are several ethernet options available for arduino boards, some of which even support power over ethernet (POE). POE would be particularly cool, since then I wouldn't have to run separate power and data lines down to the dock. POE vs. XBEE data transmission were about the same price. The decision point for me was lightning risk- running an ethernet cable down to the dock would expose my home network to a might higher risk of damage from nearby lightning strikes.

The enclosure is off the shelf electrical components from Lowe's.

Sensor Package Bill of Materials:

Item P/N Source Quantity
Arduino Duemilanove N/A 1
Ultrasonic distance sensor HC-SR04 1
Precision Epoxy Thermistor N/A 1
Air Temperature / Humidity Sensor DHT22 1
Photocell N/A 1
X-Bee Shield WRL-09976 1
X-Bee Pro, Series 1 wireless data module (100mW power) XBP24-AWI-001-ND 1
Printed Circuit Board, general purpose 276-150 Radio Shack 1
6"x6"x4" PVC outdoor wiring box N/A Lowe's 1
Redodot wet locations hinged outlet cover N/A Lowe's 1

Note: many misc. components were not included- headers to solder on to X-Bee Shield, ribbon cables, connectors, etc.

Wireless Data Receiver Bill of Materials:

Item P/N Source Quantity
X-Bee Pro, Series 1 wireless data module (100mW power) XBP24-AWI-001-ND 1
X-Bee Explorer USB WRL-08687 1

Initially this data receiver will be used bare, but eventually it should be placed in an enclosure and placed somewhere safe and out of the way.

No comments:

Post a Comment