The WiFiBat - A Remote Logger
A new project to start out 2019 !!

My friend Frank and I are always thinking up ideas for new bat projects. During a recent discussion, we talked about ways to remotely monitor bat activity. While he is looking into GSM supported ideas, I focused more on WiFi related possibilities. I had a little experience with the ESP8622 WiFi module, and wondered if I couldn't use it with an ArduBat shield to make a WiFi connected bat detector.

This project demonstrates that the ArduBat is not just restricted to the Arduino Uno R3 for development of applications. My final idea was to make a WiFi connected bat detector that could remotely upload the bat activity data, over the Internet, to ThingSpeak, https://thingspeak.com , where it could be viewed by many folks remote from the actual monitoring area. The result of the project is the WiFiBat remote bat activity logger, which adds the Simple Bat Detector circuit to the Internet Of Things.

Instead of the Arduino Uno, the controller for the WiFiBat was going to be an ESP8266. More specifically, I was going to use a NodeMCU ESP-12E module, which has the ESP8266, an FTDI serial interface, and a 3.3 volt regulated power supply on a single PCB. To simplify interfacing the NodeMCU, I soldered it on to a generic prototyping PCB that is designed for making Arduino shields. By adding the appropriate headers, it would become the base PCB for the WiFiBat.

You can see in the image to the left how the project starts out...

The images to the right show how the project progressed as I added features. First was a 5 volt power supply to bring the 12 volt battery input down to something the NodeMCU could handle safely. I also added the usual 180K / 20K resistor divider to allow measuring the battery voltage with the 3.3 volt analog input pin on the NodeMCU. Finally, a 10K resistor was added across the input of the bat pulses from the ArduBat board to bring the final pulse voltage down to 3 volts.

The rest of the work was involved in connecting the grounds, power, and interconnecting pins between the NodeMCU and the ArduBat. It was not an impossible project, but one that took planning and patience. The needed wiring was distributed between the top and bottom of the prototyping board.

Of course, I also needed to build up an ArduBat board, but that is covered elsewhere ...

In the image to the left you see the completed WiFiBat stack. The 3.5 amp-hour battery will operate the logger for 35 or more hours, which is good, as I basically intended to use it for overnight deployments. The package would be ideal for a school class that did a session on bats and wanted to monitor bats at the school overnight, or even over a weekend, with a larger battery. The students could log into ThingSpeak and see what the bat activity was from home. The next day, in class, the data could be downloaded and examined in detail.

All of the ArduBat features are used. The two push-buttons are used to enable and disable remote logging to ThingSpeak. The red and green LED's blink each 10 seconds - red if remote logging is off, green if it is on. The yellow led indicates any bat calls being processed. The reset button reboots the WiFiBat system. The WiFiBat also serves up a web page on the local network that allows the logging status and battery voltage to be checked remotely. So you can see the WiFiBat has many good features.

The module is mounted to the battery with an industrial strength Velcro, making it easy to change the module from one battery to another.

All of the firmware development was done using the Arduino IDE ... with added resources for the NodeMCU board and ESP8266 module support.

The final program / sketch provided a method for configuring the WiFiBat for the local WiFi network it would use. It provides a web server function to serve up the status page on the local network. It also sends the accumulated bat activity event count to ThingSpeak every 10 minutes ... all while constantly checking for bats !!

The image to the right shows the graph that is created on the ThingSpeak page to display the bat activity data. I didn't think that at this time of year we would have any bats about ... but it looks like the bats were out to celebrate the New Year !! ( Maybe the fireworks woke them up ... ) So I have to say that the WiFiBat seems to work very well.

I hope my WiFiBat project inspires you to come up with still more ideas of how you might use the ArduBat shield !

UPDATE - March 2019 ... making a WiFiBat has become a lot easier. ESP8266 boards designed using the footprint and connection layout of the Arduino UNO are currently available. In essence, this looks like a NodeMCU imitating an Arduino UNO !!

I got one of these boards, and it can be used very easily ... only a couple of mods are needed to the ArduBat board !! Check it out here !!

Quick Links: ... ArduBat Home Page ... Construction of the ArduBat Shield..

Tony Messina - Las Vegas, Nevada - email: T-Rex@ix.netcom.com