[QUESTION] Using the RFM69HW 433 vs 915

[lewishollow]

I followed the instructables post for this project - www.instructables.com/id/Uber-Home-Automation-w-Arduino-Pi/?ALLSTEPS, and noticed a discrepancy between the frequency of the chip in the code (an instructions) and the actual chip linked in the parts list.  I posted this question on that article as well, but it looks like the active discussion is happening here now.

The article mentions that 915 MHz is the preferred frequency to run for this project, and the code reflects that, but but the chips linked in that post are for the 433 MHz variant, which I purchased those for my project.  Was this just a typo?  Can the 433 MHz RFM69HW run at 915 somehow?  

I'm still new to the DIY electronics stuff, so please forgive me if this question makes no sense.

Thanks!

[papa]

The original Uber Home Automation project was inspiring (including for me), but had self-admitted limitations. Some limitations were addressed in the followup comments, but for me, it was hard to follow what was working & what was not. I recommend that like me, you follow what is posted in & related to this forum (which was started by the Uber author), especially CompuTourist-derived materials. I believe you will find these reliable. I especially recommend you download & extract this, & look particularly at Gateway 22 & the DHT End Node. You might look at my progressing Success... posts where I describe my build & adaptations from CompuTourist.

Now to address your question:  I have not used the 433Mhz version of the RFM69 transceivers, but I do not believe they can function at 915MHz.

If I'm right, what can you do ??  You might set those aside for another project & buy the 915MHz version with "H" (for high power) in the part name.

  OR you might use the 433Mhz version to build (for a test) the Gateway & just one DHT end node.  (CompuTourist's Arduino Sketches allow one to define the version of the transceiver mini-board, including at 433mHz.)

You'll need to research how long to make the antenna wire for 433Mhz.  My research found about 3 inches for 915MHz, but I don't know for your version.

         I also do not know if 433MHz versions communicate as far as 915Mhz versions, but you could experiment to find out.

My Success... posts describe how I built the Gateway & DHT end node where I soldered wires to the RFM69s & then plugged the other end of the stripped wires into Arduino or Arduino shield sockets.

CompuTourist's Arduino sketches allow one to activate a debug mode where the device usb-connected to your computer outputs results via the Arduino IDE's Serial Monitor.

You'll also need to get OpenHAB & MQTT service running on your computer device (Linux or Windows)

With help from debug mode, get the Gateway working & connected to the computer's MQTT service.

Then with help from debug mode, get ONE DHT end node working CLOSE to the Gateway.

Once that works, start testing the connection by moving the end node away from the Gateway, eventually the farthest distance you believe you'll need a node.

            (My 915Mhz nodes communicate across my 3 level home & a ways into my yard outside.)

     If the 433MHz version does not communicate far enough, you could unplug them, assemble & plug in 915MHz versions, & change the Arduino sketch settings accordingly.

[lewishollow]

I'll do that. Thank you!

[papa]

You're welcome, lewishollow. I installed OpenHab (1.7) & MQTT service on a Windows 7 laptop. The Uber Instructable had a fairly detailed description of installing on a Linux device like a Raspberry Pi. Though I cannot vouch for it, that (OpenHAB / MQTT install) might be helpful if you're using Linux.

[papa]

lewishollow, my post above should have said, "look particularly at Gateway 22..." that is Gateway version 2.2. I corrected the above post.

[computourist]

Hi lewishollow,

your system should work just fine on 433 MHz; just change the settings in the sketch and compile.
433 Mhz should give you a bit more range in comparison to 868 or 915 Mhz. However the 433 MHz frequency is crowded with many 'noisy' devices that could interfere. 868 MHz is used in Europe, 915 in US, Canada & Australia I think....

[papa]

Thanks, CompuTourist. I was hoping you'd give additional information. What you said is good to know.

[lewishollow]

This is all awesome, guys.  Thank you.  I saw that the defines could be easily changed to 433MHz, but I wasn't going to have access to test switching them for a couple of days, and I was fretting about having gotten an inferior chip.  I tried it out, though, and it's all working, and I'm getting great RSSI values!

I have MQTT and OpenHab on a raspberry pi and the old ethernet gateway + RFM gateway setup from the original instructions.  It sounds like that 2.2 version unifies them, which I'm excited to try.

The part I saw in the post you referenced, papa, was that it seemed like you extended your system to be able to trigger actions, like light control and such, using the same setup.  I'm very interested in that, as it would open up so many possibilities wrt having actions occur based on environmental stimuli.  Do you have a post handy where you talk about how you did that?

Thanks again, guys!  This project 100% inspired me to start tinkering with electronics and DIY stuff like this, and it's been a blast.  

[papa]

Thanks for your comments, lewishollow. It is indeed a blast & when we get a bit of this working, the possibilities are inspiring & exciting.  Maybe it's just me, but this project feels VERY COOL & POWERFUL with practical results.

You might see my Success... posts of Sep 19, 2015 at 4:27pm & Sep 22, 2015 at 7:51pm about building a DHT node on a 3.3 volt friendly prototyping shield to be plugged into the Buono Uno. As said there, I have not yet documented all of it (been a little busy helping some newbies on this forum ;-) but what I posted so far could keep you busy for a while (especially if you must order some of the parts I showed in the schematic).

From what CompuTourist told you & you successfully tested about using the 433MHz version of the RFM69 transceiver, sounds like you could substitute that in place of the 915MHz version & substitute that 433MHz option in the sketches.

I've built that DHT end node with both a DHT11 temperature/humidity sensor & a solid state relay that can switch on/off AC devices via OpenHAB virtual switch in the browser, via OpenHAB app on my iPhone, via the push button on the node, & via OpenHAB rules with pseudo random scheduling. I need to document this further, but the above will get you started.  Study the schematic for parts to have.  Follow the assembly instructions so far & you'll have room for the other features I will document.

PS  I have not switched AC devices based on sensor data (like turning on a light based on a sound, daylight or temperature sensor), but I don't believe it'd be too hard to add.