April 2016
I want to build two projects.
I would appreciate guidance on platforms, hardware, etc. As always, any insights and feedback are appreciated.
Please log in to post an answer.
For the wireless networks such as yours, I recommend Digi International XBee 802.15.4 modules. They're easy to use and operate across 100 feet indoors. The XBee-PRO modules have a longer range — approximately 300 feet, but they use more power. You can get longer ranges outdoors. Both operate at 2.4 GHz. The XBee modules let you transfer serial information right away. Or, you can configure them with free XCTU software from Digi to transmit API commands to remote devices and have the remote devices respond with digital and analog readings. (No code writing required.)
Internal 10-bit ADCs simplify measurement of voltages from a temperature or humidity sensor such as those sold by SparkFun or Adafruit. The XBee modules have sleep modes that save battery power. They can wake up at a given interval, transmit data, and go back to sleep. The XBee modules operate from two 1.5 volt D cells, so remote power is easy to provide.
Sound measurements require some sort of logarithmic response for decibel values. I recommend you use an LM3915 dot-bar display IC to convert sound levels to dB ranges. Most circuits use this inexpensive IC to drive 10 LEDs in a visual sound meter but you could use the eight most-significant outputs (without LEDs) to drive the eight digital inputs on an XBee module. You'll need a pull-up resistor on each of the eight LM3915 outputs. The LM3915 data sheet provides good application information and example circuits: www.ti.com/lit/ds/symlink/lm3915.pdf.
At the receiving end you use another XBee module and connect it to your PC through a USB adapter such as the SparkFun "XBee Explorer USB" or the Parallax "XBee USB Adapter Board." A serial terminal emulator on a PC lets you see the received information. You could write a VisualBasic program to parse the raw data from the XBee into in degrees, percent relative humidity, and decibel ranges, and then save data in a file for later analysis.
For more details, circuits, and software, I recommend, two books, "The Hands-On XBee Lab Manual," and "Wireless Sensor Networks." The first provides information that directly relates to your needs. The latter concentrates on use of the ZigBee protocol for networks of sensors, but you must use XBee ZigBee modules.
Maybe a bit complicated, but appears to be a solution: www.instructables.com/id/ESP8266-WiFi-temperature-and-humidity-logger/?ALLSTEPS
