Hello everybody,
I intend to implement a little project which imply using Moteino platform because of it's great advantages (low power, long range).
I'am in the planning process in order to make the acquisitions so I need a little help with some aspects
- The project is 2 floors below the ground level and one above (-2 floor, -1 floor, 0) and the surface is approx. 6500 square foot
- There is a lot of concrete and metal in those floors below the ground level
- I need these kind of sensors
1. water sensor (flood) - have no idea what to use
2. carbon monoxide sensor - have no idea what to use
3. active voltage phase detection - have no idea what to use
4. door garage opener - there is documentation
5. light sensor - there is documentation
6. motion sensor - there is documentation
I intend to have the Pi gateway at the 0 floor but I can place it anywhere if it is necessary and get by UTP cable to my final destination.
Please, if as experienced user you can give me some advices in
- what kind of moteinos should I buy (high power, low power)
- What sensor can I use for those that there is no documentation (first three)
- Should I use more Pi gateways because of concrete and steel? Can 2 gateways be used in the same project?
I also can have UTP wires in places that I need in case that Moteino can't have radio links.
What is your advice - is this project feasible using Moteino framework?
Thank anyone who can help with any little advice, it will be welcomed.
Hi Laurentius,
First see this thread (https://lowpowerlab.com/forum/index.php/topic,562.0.html) where there is reported range in a multi storey structure.
I would recommend the 915mhz-HW if you're in the USA, it's up to you what actual Moteinos you want .. just bare Moteino or MoteinoUSB or MoteinoMEGA .. they are largely the same except the USB has the USB built in so no need for an FTDI adapter, and the MEGA uses the atmega1284p and has a lot more IO and more chip functions and an extra hardware serial etc.
Understanding how the various settings of the radio work will help tremendously with getting the range you want even in a heavy concrete building. See liked post above for more on that.
If you search this forum you will likely find some solutions on water sensing. If you want to detect water presence, a resistive element could probably be used, I've seen them on ebay for cheap. Active voltage detection ... this depends on how high the voltage is. In my doorbell project I use a 24VAC detector circuit which goes HIGH when the doorbell is pressed and voltage flows through, then interfaced to a Moteino it can send a message when that happens. If you have 120/240VAC then you can probably use the same type of circuit but with some modifications to support the high voltage. Not sure what to advise on carbon monoxide, there are relatively cheap alarms at Home Depot, maybe you can tap into one of those and send a signal when the alarm goes off.
Thank you Felix,
I will follow you advices and study which Moteino I will use and also the sensors. Probably I will order HW version and one-two low power version for testing.
For voltage my need is for 220V, so I will read your doorbell project - is the same situation, I need to know when an elevator is used. For Moteino I will need european version. :)
Have you ever used 2 Rpi gateways in a project - this is in case that I need crossing huge size walls...?
Also for Rpi gateway I will try to have a functional gateway using my lovely Alpinelinux distro which is very secure and loads totally in RAM, is designed for embedded systems and eliminates probability of corrupted file system on the SD card. Maybe you can have a look at this great distro and considering it for some of your future projects.
For carbon monoxide is a good ideea, sincerely I didn't think of a such a solution.
Your work is great, I'm very glad that I discovered Moteino framework.
Any ideea from Moteiono community is a great help for me.
Many thanks.
Quote from: Laurentius on October 07, 2015, 11:23:01 AM
3. active voltage phase detection - have no idea what to use
If you just want to detect the presence of 220 VAC in a wire, you could probably use a simple CT sensor, such as this (https://www.sparkfun.com/products/11005) (or on eBay). It's non-invasive (no need to break the circuit for detection) and safe since there's no galvanical connection to the wires.
I definitely think that the Moteino framework is a good choice for this task. If you find that not all your motes can reach a single GW, you could use a relay node on the other floor and wire it to the Pi via RS485 or similar signaling for longer distances - since you mentioned you can employ suitable cabling, it might be feasible for you.
CT for detecting high voltage presence is definitely a good choice. It will be a sine voltage proportional to the detected voltage.
I have not used 2 PIs, before you plan too much for that I would recommend trying two RFM69HW radios and do your initial testing with them to see what range you get with out of box settings, perhaps tweaking the settings will get you more and satisfy your indoor needs.
The current transformer, of the clip-on type reference by kobuki, is used for measuring AC current through a wire. It is totally independent of (and isolated from, as kobuki pointed out) voltage. So it won't detect the presence of voltage but will provide an AC signal proportional to the current through the wire. This, of course, implies the presence of voltage, but voltage may be present and without load, will have no current, and therefore may produce no signal with this sensor.
I use this type of sensor in my "honest" RMS sensor project: https://lowpowerlab.com/forum/index.php/topic,1036.0.html
This sensor is very good at measuring current, however, if you want to measure/monitor voltage, independent of current, it is trickier to do with an isolated method.
Tom
Quote from: TomWS on October 07, 2015, 11:43:48 PM
The current transformer, of the clip-on type reference by kobuki, is used for measuring AC current through a wire. It is totally independent of (and isolated from, as kobuki pointed out) voltage. So it won't detect the presence of voltage but will provide an AC signal proportional to the current through the wire. This, of course, implies the presence of voltage, but voltage may be present and without load, will have no current, and therefore may produce no signal with this sensor.
I think OP wants to see if an appliance is turned on and thus current is flowing. He can threshold or detect the presence current by sampling an ADC channel in the mote. For fixed appliances I think it's a very simple and safe method for this task. Well, I hope he'll chime in some day to clarify.
Quote from: kobuki on October 08, 2015, 05:35:20 AM
I think OP wants to see if an appliance is turned on and thus current is flowing. He can threshold or detect the presence current by sampling an ADC channel in the mote. For fixed appliances I think it's a very simple and safe method for this task.
I agree this is a totally appropriate application for this sensor, IF that is what OP wants. If he really wants 'voltage presence', this won't do it.
Quote
Well, I hope he'll chime in some day to clarify.
Agree completely here. :)
Quote from: Laurentius on October 07, 2015, 03:36:27 PM
For voltage my need is for 220V, so I will read your doorbell project - is the same situation, I need to know when an elevator is used. For Moteino I will need european version. :)
Though, it might not be that simple. Even if he's most probably not going to need to tap into HVAC conductors, it might be troublesome to place a sensor (whichever kind) there. Maybe some motion or distance sensor is better suited. He might be required to arrange a permit or have a sensor installed by a representative of the elevator mfg. Elevator rules are pretty tight here in the EU (understandably).
Hello dear Moteino comunity,
Like your project Tom, I need to see if I have a consumer (the elevator is used in that moment) and I need it to be non-invasive because of tight regulations.
Also I want to ask what is the best sensor can I use for water flooding (like detecting a pipe was broken and there is water on the floor).
Have anyone experience with a shale (natural) gas detector? I was thinking to incorporate such a sensor in my project.
I consider using HW version of Moteino but I will experiment with low power version and come back with feedback.
Thank you all for your great suggestions, you are all my friends. :)
Quote from: TomWS on October 07, 2015, 11:43:48 PM
The current transformer, of the clip-on type reference by kobuki, is used for measuring AC current through a wire. It is totally independent of (and isolated from, as kobuki pointed out) voltage. So it won't detect the presence of voltage but will provide an AC signal proportional to the current through the wire. This, of course, implies the presence of voltage, but voltage may be present and without load, will have no current, and therefore may produce no signal with this sensor.
I use this type of sensor in my "honest" RMS sensor project: https://lowpowerlab.com/forum/index.php/topic,1036.0.html
This sensor is very good at measuring current, however, if you want to measure/monitor voltage, independent of current, it is trickier to do with an isolated method.
Tom
Tom and I are working to integrate Tom's ATC variant of RFM69 which includes auto power dial to reduce power levels depending on desired received signal strength. This is useful to make the radios lower power when transmitting, rather than transmitting at constant high power regardless of conditions.
Many leak detectors are single point detection. Depending on your situation, you may want to detect over a wider area than a single point. If such is the case, rope detectors may be more appropriate. Example:
http://www.amazon.com/Honeywell-RWD41-Water-Defense-Sensing/dp/B0049U3XE2/ref=sr_1_1?ie=UTF8&qid=1444324602&sr=8-1&keywords=honeywell+leak+detector
There are also mat detectors that have an even larger detection area for more immediate detection.
In both cases you could still wire a Moteino to them, so you still can get wireless notification. In addition, you can wirelessly monitor the battery status of the sensor, and even by itself that's a nice perk. :) After all, even the best sensor isn't going to sense if all it has is dead batteries.
It will be a nice feature to reduce the power depending the signal strength.
Also a rope detector can be a good ideea for a flooded floor.
Have anyone had any experience with shale gas sensor working with Moteino framework?
Thank you for your valuable suggestions.
Quote from: WhiteHare on October 08, 2015, 01:22:15 PM
Many leak detectors are single point detection. Depending on your situation, you may want to detect over a wider area than a single point. If such is the case, rope detectors may be more appropriate. Example:
http://www.amazon.com/Honeywell-RWD41-Water-Defense-Sensing/dp/B0049U3XE2/ref=sr_1_1?ie=UTF8&qid=1444324602&sr=8-1&keywords=honeywell+leak+detector
There are also mat detectors that have an even larger detection area for more immediate detection.
In both cases you could still wire a Moteino to them, so you still can get wireless notification. In addition, you can wirelessly monitor the battery status of the sensor, and even by itself that's a nice perk. :) After all, even the best sensor isn't going to sense if all it has is dead batteries.
Rumors of my demise have been highly exaggerated (I'm happy to say)! ;D Been fighting floods at both ends of the trip and dealing with recovering a hard drive crash on my workstation. Plus a number of maintenance issues that seem to creep in whenever one is not around to keep a close eye on things...
In any case, I concur with Whitehare's recommendation on a rope sensor. As I understand it these are used extensively in boats, computer floors, and anywhere a large area needs to be monitored. And rope sensors can cover a VERY large area because you can line the perimeter of the area and any water leaking INTO the area is detected.
Tom
UPDATED: added comment re area covered by rope sensors.