BWSN Troubles with Wireless

I bought Building Wireless Sensor Networks by Robert Faludi book and I’m trying to work my way through the examples. Which is easier said than done. (Laugh)

With all projects, it helps if you plan out what your going to do. In this case I bought and read the book and started an engineering notebook to detail what the goal is, what parts and equipment were needed and organize and write the source code.

From my experience the hardware needed for the book:
1) The book: Building Wireless Sensor Networks by Robert Faludi of course this should be the first step.
2) BWSN Basics Kit. This kit doesn’t include any Arduinos, so if you only buy this kit, be sure that you have at least two of them. You can also buy them online at many places, here is a link to SparkFun Arduino Uno’s. With two Arduino’s you can do all the projects up to Chapter 6.
3) BWSN Advanced Kit. This kit includes two Arduino Uno’s. It’s also quite expensive.
4) The BWSN Advanced kit only includes one USB A-B Cable”. I prefer to work on the Arduino’s when they are both plugged into the PC. Quicker to troubleshoot and update the sketches as needed.
5) A Soldering Iron plus some lead free solder. Some of the items in the BWSN kit need to be soldered together.
6) 22 AWG hook up wire in various colors: Black, Red, Yellow, Brown … others are available. SparkFun has a good selection. I personally bought the pack of Jumper Wires because I didn’t like the wires SparkFun included in the BWSN Basics Kit.
7) Anti-static mat. If your soldering things together, you will need a anti-static mat.
8) I also bought two of Adafruit’s XBee Adapter Kits because you can plug them in vertically to save space on the breadboard. It also includes an LED to indicate activity (RSSI) which is very handy if you want some indication that the device is communicating. It also does some handy voltage level shifting so I don’t have to worry too much about what voltage I’m feeding the XBee.

Project from “Chapter 2: Up and Running” is very simple and its goal is to verify that you can install the X-CTU software, update the firmware for the two XBee’s and verify they can communicate. Unfortunately, I had the hardest time with this. I plugged them all together and couldn’t get anything to communicate. Tried swapping out XBee’s, swapping out the adapter kits, searched for a driver issue. Nothin’! After several hours of scratching my head I realized that of all the things I swapped out, I didn’t change the cable. Yes, of course, bad cable. How can a USB cable go bad? (Shrug) Cosmic rays I guess. Once I swapped that out, the X-CTU communicated with the XBee’s without any problems.

So my issues with this project so far:
A) I dont like the Jumper Wire Kit that’s included in the BWSN Kits from SparkFun. It doesn’t include any black wires, the wire ends are already bent which is good for the short wires(maybe), but not for the long wires when I need to span over things. (Shrug)
B) Why OH why does SparkFun include such a large honking Push Button in the BWSN basic kit? The plug on the back can’t plug into the breadboard and I have to solder some wires to connect.
C)Finished “Chapter 3: Build a Better Doorbell” and I have some issues with the instructions. Just assembling a circuit, giving it a try then giving some generic advice on how to trouble shoot I believe does a disservice to the user. I would have preferred that they author build up simpler projects that lead to the final doorbell project. For example, I took the two brand new Arduino Uno’s out of the Advanced BWSN. I have no idea if they work but I want to verify that do. Attach an LED and write a sketch to blink the LED. Next add the push button, write a sketch that blinks the LED when the button is pushed. Next plug one of the XBee’s to the adapter kit and connect it to Coolterm. Attach the other XBee to the Arduino and verify that I can push the button the LED blinks and the serial data appears from the Arduino to Coolterm. This verifies the Arduino, push button, LED and the XBee all work and will work together. Then do the same for the buzzer side of the doorbell project. (shrug)
D) For your reference the LED positive lead is the longer wire and the negative is the wire next to the flat bit on the plastic. The BWSN book didn’t get around to mentioning this till Chapter 4. I’m ashamed to say I had to google it. (hangs head in shame)
E)The BWSN Basics Kit includes little baggies of resistors. Do yourself a favor and spend a few minutes reading the color values and writing the values on the bags. It will make putting together the circuits much easier when you don’t have to stop and hunt up the correct resistor.
F) Some of the figures that show the Arduino and XBee on a breadboard aren’t very clear. I wish they would have labeled the 3.3V and GND rails on the breadboards and include clear pin numbers on the XBee.

Stay tuned, I’m sure I’ll have more when I get farther into the book.

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