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Objective: Maybe I'm a bad Googler, but I am finding very little on wired Internet of Things sensor networks using Arduino.

Project Goals:

  • Arduino based sensor nodes that connect to the local network (not out to the internet)
  • All the benefits of adding adding/removing nodes, moving nodes, adding new routers for more ports.
  • Black box sensors that don't take any soldering to plug into the network (although they contain soldered components in the black box.
  • Using a master Raspberry Pi on the network to identify the nodes and read data from them.
  • Using Power over Ethernet (PoE) to power my sensor nodes.
  • Don't want to actually connect to the outside internet, just want the convenience of assembling a network with node names and such.

Why not use wireless solutions (e.g. XBee):

Currently, it seems Xbee is the way to go, but I don't want a wireless solution.

  • I want the reliability of a wired connection.
  • I don't want to have to worry about batteries

What I'm doing right now:

Currently, I have all my sensors wired to a central Arduino MEGA using 4-conductor security cable (Vcc, GND, and two signal conductors). The MEGA communicates over serial with a Raspberry Pi. This is annoying for the following reasons:

  • I have to solder/unsolder every time I want to change something.
  • I have to figure out which digital I/O pins are available on the MEGA and have to write down which signal conductor goes to which pin on the MEGA and means what on the sensor.
  • There is a finite number of pins.
  • Each sensor is its own unique project. I want to start standardizing these sensors to clean up the code.

What I have found so far:

I've been looking at XPort sensors; however they are very expensive (i.e. $60 ea.) and don't support PoE. If there is a solution using Arduino and an Ethernet Shield, it brings down the base cost of a sensor by a lot.

Request:

Where can I find out more information about wired Arduino sensors? Are there any prebuilt solutions that already do what I am looking for?

  • Since you don't want to connect to the internet, you could just use any protocol over those ethernet cables (they are just copper wires). Something like RS485. – Gerben Jun 13 '16 at 18:22
  • I was hoping to be able to use pre-existing equipment to handle some of the work for me (i.e. add new ports by adding routers/switches, having them assign new addresses automatically). – Michael Molter Jun 13 '16 at 18:31
  • MySensors.org supports RS485, while qualifying as an IoT platform. It might be worthwhile to consider ethernet<->serial gateways. – sekdiy Jun 14 '16 at 7:54
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I think I am using a setup like you wish at my home:

  1. PoE Switch (for example Cisco SG300-28P)
  2. Arduino Ethernet's with PoE Module (https://www.arduino.cc/en/Main/ArduinoBoardEthernet) I bought one for every room ;-)
  3. Use DHCP-Server on raspberry PI
  4. Put your sensors on your Arduino ethernet board
  5. I am also using MQTT as protokoll for example http://pubsubclient.knolleary.net/
  6. Use MQTT broker Mosquitto on raspberry pi

For the case that you want to use your switch also for internet connectivity, define a vlan (search wikipedia) for your arduino sensor network.

Hope that helps.

  • I'm curious how/where you bought the Arduino PoE modules. Everywhere I look they're "retired" and unavailable. – Chuck Claunch Jul 24 '16 at 15:09
  • Because I am located in Germany, I bought them at: Watterott.com also Exp-Tech.de has them available (at the moment ;-) It is no problem to solder the PoE Modules yourself into ethernet shields. – PowerStat Jul 26 '16 at 5:21
  • Ah, yes I have seen those modules here in the US as well that you can add to the Ethernet shield, it just seemed rather costly ($13 for the module + ~$30 for the shield + the arduino cost itself). I managed to find a complete PoE shield on ebay for $20 but that was a one time deal and I'd like to build several. Thanks for the help. – Chuck Claunch Jul 27 '16 at 13:34
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Enviromon.net has PoE sensors that are plug and play with their base units. The base unit is then connected to your internal network.

If your a bit more experienced (which it seems you are) their base units can also be integrated into other systems like network monitoring apps, and SCADA programs.

You could most likely configure the base unit to slave to your raspberry pi, and bonus, no soldering. All their sensors are PoE. Although unfortunately they are not for the Arduino.

But you mentioned if anyone knew if there was a prebuilt solution.

Heres a link to their sensors you might be interested in http://www.enviromon.net/environmental-monitoring-sensors/

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