Help getting started - temperature sensor network for beginner



  • First post. Thanks to anyone who takes the time to read and respond. After spending some time on the site and forum to day this looks like an active community so I am optimistic that I'll get some readers!

    Personal Background: Studied computer engineering undergrad but it's been 6+ years since I've done any legitimate programming or hardware work. I'm willing to put in the work and learn but am aiming to hack things together based on others' code and descriptions rather than writing any new software. I have no experience with Arduino, Raspberry Pi, or other DIY platforms commonly mentioned on MySensors.

    Project goal: Create a temperature monitoring network in my apartment building. We live in an older building and frequently have owners complain that it's too cold in the winter. We'd like to monitor temperature in multiple units to see whether the complaints are real and where specific problems may exist. There are 12 units on 6 floors. The goal would be to put sensors in approximately 5-8 of the units and relay the data into my apartment, where it would be logged. I would like to do this project inexpensively. Depending on the success of this project I may pursue follow-up projects, but for now I don't need to do anything "fancy"; it just needs to collect the temp. data from each node wirelessly and store the information. Refresh speed is not important; a reading every few minutes would be perfectly adequate.

    Questions:

    1. Does anyone here know of a similar project for which someone has posted instructions that I could use?
    2. What gear do I need to accomplish this? It's not 100% clear to me from reading the 'components' section of this site what I actually need.
      a. Sensors: From what I gather, each sensors will require an Arduino board, radio, and sensor (and possibly a resistor, capacitor, or two)?
      b. Gateway & controller: Sorry if I've missed something on the site or am being dense but what's the difference between these two? Do I need to have something expensive like the Vera Edge? Can I use a Raspberry Pi setup instead (eg with the B+ board)? I have an old laptop that can be dedicated to this project - can that be used in some way?
      c. Other stuff? Breadboards, soldering iron, etc?
    3. Will the software tools provided by MySensors be sufficient for what I'm trying to achieve with basic hardware?
    4. Is this project too ambitious for someone who's brand new to this field?

    Assuming I take this on, I plan to document my project closely and hope the content will be useful to other newbies interested in getting back into tinkering and playing with code.

    Thanks!


  • Admin

    @majic

    I'm preparing almost the same scenario as yours, only difference is that I'm not going to use it in apartments, but in my own house, one sensor in each room to measure temperature and humidity. I'm making my own dedicated sensor PCB though.

    As of now, to get a MySensor network up and running you do require some soldering, as there is no ready build sensors. There are some people working on an official MySensors module, that require minimal or no soldering. So depending on the timeframe, you could start in building something basic (1 or 2 nodes, and a gateway) and start experimenting with that.

    You could use what ever you have arround for a controller, be that a Raspberry Pi, or an old laptop. There are different controlers, most of them are made for automating things (turn light on / off, etc.) and not for just measuring temperatures. So they might be a bit overkill. I haven't investigated that much of the controller section yet myself, as I am pursuing some minimal automation thing here.

    One thing that comes to mind, is How far is there from your appartment, to the farthest unit that you want to measure in? And what is the materials used in your building? If there is lot of steel reinforced concrete, then it might interfere with the radio signals from sensors, and make things difficult.

    for question 4. It's depending, if you want to learn something new :) And think that electornics is awesome, then no it's not too ambitious :) IF you only think that electronics is "something blackmagic inside a telly" then it might be :)



  • @majic Hi, as @tbowmo sad it may be problem with MySensors range, because you are having 6 floors. Of course you can use relay nodes, but why complicate things. If you are already using WiFi network in your building maybe ESP8266 WiFi module is better choice.



  • @majic
    I think it can be done almost without soldering, at least in the prototype phase.
    I started recently with a similar project as yours, using hardware from ebay. Pro-mini + nrf24L01 radio's and some ds18b20 temperature sensors and a usb-serial-ttl converter. All (4xpro-mini, 4x nrf24L01, 5xds18b20) around €20. My goal is to get a sensornetwork up and running, but without an (expensive) controller like the VERA as is used in here. El cheapo, but working. It's a hobby...and should stay a hobby.
    I'm currently at the status that I have an serial-gateway and a single node talking to each other. The node uses the ds18b20 ic's for temperature and sends it to the serial gateway. From there I use a datlogger (based on LabView and serial communication) to log the received data. All working for some days now.

    What is missing at the moment is the knowledge how to get a repeater node up and running, thus getting a larger distance covered by using the network possibilities. I think I have to start a threat on this as I could not find relevant info here in the forums. Maybe anyone can point me if there is some...

    About your initial questions:

    1. No precise instructions I think
      2a. need Arduino's (pro-mini, radios, breadboard, dupont cables, sensors) won't be that expensive, but of course depends on your situation / perception
      2b. I'm trying without the controller, even without an RB-pi. Old laptop should be usable I think if you can communicate to your gateway via your own written controller....
    2. Yes, I think so. Changed some minor things, and it works at the moment
    3. Depends on your background. I'm a mechanical engineer, but got it working...

    Good luck, and keep posting your results!

    Boozz



  • Many thanks to @boozz , @EasyIoT , and @tbowmo for their quick responses and encouragement. After spending more time on the site and hunting around on eBay I've come up with a possible parts list that I think should get me well on my way to setting up a 4 node network with room for expansion by adding more Arduino boards. All for about US $70 (including shipping).

    Parts list is below. Some follow-up questions for others:

    1. With the MySensors library and guides will this gear allow me to set up 4 of the Pro Minis as wireless temperature transmitters and the 5th board connected to a laptop as the receiver?

    2. Thoughts on using Linux vs. Windows as an operating system for Arduino projects?

    3. Any recommendations on battery setups for the temp sensor boards? 2 AA batteries and a step-up power converter for each one?

    4. Should I consider getting 5V Pro Minis instead of the 3.3v? I'm thinking it's easier to use the 3.3v's because then I don't need a voltage regulator between the arduino and the transmitter. However, if the transmission range is significantly worse, that could change my mind. But I'm hoping that the "sensor-repeater" setup would overcome this issue.

    5. Is it worth getting an 'easier to use' Arduino like the Uno? I feel like I should be fine with the Pro Minis and breadboard setup.

    Parts list with links:

    • 5-pack Arduino Pro Mini Atmega328 3.3v 8M board and FTDI USB-serial adapter [$14]: link
    • FT232RL USB-serial adapter [$5]: link
    • 10-pack of NRF24L01+ Wireless transceiver [$11]: link
    • 10-pack of DS18B20 Dallas temperature sensors [$11]: link
    • Breadboard + 65-pack of male-male jumper cables + Power Supply [$7]: link
    • 5-pack of mini breadboards [$5]: link
    • Assorted pack of 600 resistors [$5]: link
    • Assorted pack of 100 capacitors [$5]: link
    • Assorted packs of male-female jumper cables and female-female cables [$3]: link and link
    • Soldering equipment TBD. Will buy on Amazon or may be able to get some used gear from a friend.

  • Contest Winner

    @majic said:

    Should I consider getting 5V Pro Minis instead of the 3.3v? I'm thinking it's easier to use the 3.3v's because then I don't need a voltage regulator between the arduino and the transmitter. However, if the transmission range is significantly worse, that could change my mind. But I'm hoping that the "sensor-repeater" setup would overcome this issue.

    Consider the voltage and power as separate , however related, issues. Getting the most out of the RF requires plenty of power standing by...use a good power supply and caps on the radio. The other issue is wether you want to power up for sensors that may need 5V or powering down from 5 to 3.3 for the radio... There is no definitive one way, but you are absolutely on your way to success!


  • Hero Member

    @majic Just be careful, I believe alice1101983 has been sending out NRF24L01 (the non + version); you need the + version.



  • @ServiceXp said:

    @majic Just be careful, I believe alice1101983 has been sending out NRF24L01 (the non + version); you need the + version.

    Thanks for the tip. Another option I found from a US-based seller ("flygoodly") for about the same price: link



  • Shameless plug for my post, but if you don't want to involve a HA controller, my setup may be perfect. It requires some linux experience to set up but anything you need can be Googled. A perl script reads sensor data and stores it in a sqlite database where you can query it any way you want. Runs on a dirt cheap Pogoplug which has the added benefit of using very little power.

    http://forum.mysensors.org/topic/719/graphing-sensor-data



  • I should also point out; the same thing could be done by any computer you don't mind leaving on. Just install perl(and the serial/sqlite libraries) and maybe make a few tweaks to the script. You could simplify it more by just writing the data to a file as comma separated values and use excel to graph it.



  • @pete1450 said:

    I should also point out; the same thing could be done by any computer you don't mind leaving on.
    ...
    You could simplify it more by just writing the data to a file as comma separated values and use excel to graph it.

    Yes, this is what I am hoping to do, at least for the proof of concept phase - get a small network of sensors set up with pro minis, dallas sensor and the NRF24L01+ , use one board as the gateway, and skip the controller. Write the data to a text file and dump it into Excel to check on it each day. A more complex setup could come later if I decide to do other interesting things.

    Thanks for the link to your project. Using the pogo plug sounds interesting.

    Did you wind up getting the Vera for Christmas? If so what's the plan? Nano->Vera as a controller and then use the Pogoplug as a web server?



  • I did. Vera will be the controller and the pogoplug will be used for logging data and serving pages to report on it.



  • I want to get temperature data from multiple nodes.
    I have connected nodes via DHCP 01, 02 upto 05 to Master 00.
    & When i add New node in dynamic network it showing address 012 on Master node 00
    But i am not able to receive transmitted data from 012 node to master node....
    myCode: https://goo.gl/ggTei4 & Photo : https://goo.gl/Sq28tC

    Thank You



  • @majic
    Are you able create the wifi network in all your house?
    ( wifi bridges on each floor etc? )
    If yes, then buy some Sonoff units, flash ESPEasy to them, connect Dallas temperature sensor, plug in to the electricity outlet in each flat and instal Domoticz in your computer.
    You can see graph data on your computer then.


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