Hi, I am trying to design a smart rope. Basically i have about 100 ropes around my property and I want to know if a rope rips or get out of alignment. So I want to put some sensor on the rope (altimeter, gyro, accelerometer, load cell, gps, or s/t) and have it send an sms if certain values change more than a specific amount.

 

Welcome to AAC.

At first blush your proposal seems very expensive. But, that’s partly because it is short on detail.

Could you explain what the ropes do, how long they are, how far apart, the material they are made from, etc.
What is the climate like in your area?
How sensitive does the detection have to be?
What does “out of alignment“ mean in this case?

More information will probably get you some help in evaluating the feasibility and implementing your scheme—or something possibly entirely different that solves the problem this is supposed to.

 

Hi, Yaakov

Thanks for responding so quickly.
The ropes in this case don’t actually do anything. They are there for religious reasons. Most Orthodox Jewish areas have them. They are typically nylon fishing string attached to metal poles about 50-100 feet apart strung about 10-20 feet above the ground.

if the string tears or the alignment changes such that the rope is sagging substantially, it is not “kosher” for the sabbath.

I live in NJ, but if this works, I would like to use it also by my parents in Florida, so the weather can run from snow to hurricane

thanks again. Please send your thoughts

 

The eyes are great for detecting such things, so I would suggest a camera connected to the internet.

 

The eyes are great for detecting such things, so I would suggest a camera connected to the internet.

One problem is power supply that camera would need. Also no wifi service in some parts of the area

 

So I want to put some sensor on the rope

What about an old fashion mercury switch, battery and buzzer? Might need two separate setups, one near each end of the string.

 

What about an old fashion mercury switch, battery and buzzer? Might need two separate setups, one near each end of the string.
View attachment 295416

I like this idea. But let's add a text message or radio signal, because the ropes are too far to hear the buzzer.

 

What's the distance needed for radio?
What about a strobe light?
https://evandesigns.com/products/quick-burst-stobe-flash?variant=39715135750192

 

If you want to spend some bucks this camera should work.
https://reolink.com/us/product/reolink-go-plus/

 

Hi, Yaakov

Thanks for responding so quickly.
The ropes in this case don’t actually do anything. They are there for religious reasons. Most Orthodox Jewish areas have them. They are typically nylon fishing string attached to metal poles about 50-100 feet apart strung about 10-20 feet above the ground.

if the string tears or the alignment changes such that the rope is sagging substantially, it is not “kosher” for the sabbath.

I live in NJ, but if this works, I would like to use it also by my parents in Florida, so the weather can run from snow to hurricane

thanks again. Please send your thoughts

OK, you have an eruv and you want to monitor it. This is not a simple thing to do. One of the problems is that you may well have a kosher eruv then get an alert just before bench licht that something is wrong, not knowing whether it is a real problem with the eruv or a false alarm. If you had no monitoring system, you could have relied on the fact that the eruv was known to be kosher before Shabbos, but what do you do now?

This is particularly true when the eruv is mostly covering areas that are a carmelis, as many are, and not really reshusim harabim. So instead of helping you keep the eruv kosher it might be pusseling it “automatically”.

The other trouble is the complexity. To one even passingly reliable, your monitoring system has to have a consistent source of power, be very weatherproof, and be “supervised” meaning checking in periodically or being polled to ensure each node is still operational.

Since the line can break anywhere, you need to either monitor the tension at the lechis, of the parallelism of the line versus the ground. This would require sensors for every individual tzuras hapesach. This is a major undertaking, as would be the mesh network required to manage the entire thing. I am going to guess though not completely blindly, that if you could manage to do something effective you’d be looking at maybe 50 bucks per tzars hapesach.

My advice, quite seriously, is to organize a good group of checkers and manage them well. Also, talk to a poser who is expert in eruvin about whether a monitoring system seems to be a good idea. Eruvin are extremely political, and can become a big mess if some people won’t rely on it.

I know it seems that a monitoring system would make the eruv more reliable, but the ironic possible unintended consequence is the opposite. Really focusing on good conventional checking is the route I would go. Working out some technology to make that easier, like maps on tablets, recording keeping, etc. might be a better direction.

One other thing: if you have particular sections that are known problems it might be worth instrumenting those in particular and arranging the alerts so they don’t happen when there is no time to fix things. But, of all the possible things that you might ask a shayla about anything to do with eruvin is certainly one of them.

I wish you great success whatever route you choose, and it should all be for good.

 

What on earth? Sorry I'm just now hearing of this. I had no idea Judaism had such such traditions. Googling some of @Ya'akov's buzzwords I came across the Wikipedia article on this topic, which says:

An eruv allows Jews to carry, among other things, house keys, tissues, medication, or babies with them, and to use strollers and canes.

So what happens if the eruv breaks? Do you have to drop the baby? If so, I think prevention is the better solution than detection. Can it be made of anything? If so, use steel wire rope. It won't break unless someone breaks it deliberately and with considerable effort. Also, if you use insulated mounts, it can also offer detection in the form of continuity. As soon as it breaks (is cut down by a person) it can trigger an alarm. If steel isn't allowed, ordinary copper wire offers the same benefit.

 

I would attach BMP581 + ISP4520 to the middle of each rope, it is monitored using LoRa wireless.
The power source can be a SOCl2 battery or a small solar cell combined with a BQ25504.

 

What on earth? Sorry I'm just now hearing of this. I had no idea Judaism had such such traditions. Googling some of @Ya'akov's buzzwords I came across the Wikipedia article on this topic, which says:



So what happens if the eruv breaks? Do you have to drop the baby? If so, I think prevention is the better solution than detection. Can it be made of anything? If so, use steel wire rope. It won't break unless someone breaks it deliberately and with considerable effort. Also, if you use insulated mounts, it can also offer detection in the form of continuity. As soon as it breaks (is cut down by a person) it can trigger an alarm. If steel isn't allowed, ordinary copper wire offers the same benefit.

This is venturing off-topic, so only q brief reply.

The eruv us a Jewish legal construct designed to ensure the the rules concerning the Sabbath prohibition against transferring from one domain to another is not violated inadvertently. Because religious Jews are very careful to follow Jewish Law, it becomes very important to attend to the details.

Although people talk about “carrying”, the real concerning is moving any item among the various domains that are specified in the law. Primarily between a private and public domain. There are others, but those two and one called a carmelis which is a kind of nowhere area that doesn’t share the requirements of the other two.

A carmelis can be turned into a private domain using an eruv which is a sort of legal fence. This fence is essentially the evidence that the area has been surveyed and laid out to describe a boundary in which there are only permitted domains and carmelis domains and so renders the enclosed space a single domain.

This prevents “carrying”, that is transferring from one domain to another and allows for doing things that are otherwise not permitted due to it. The foregoing explanation is extremely shallow but I believe it explains the character of the situation well for casual observers.

As far as dropping babies, no. One thing to be aware of is that Jewish Law has a hard override concerning people’s health and safety. So that would never happen. Dropping money? Yes. That would happen, I’ve seen it.

As far as using continuity, the idea is basically good but practically fraught. First of all, most eruvin don’t have a complete circuit They can and do use existing structures (e.g. fences) as part of the eruv.

There is no requirement concerning the material that can be used, but another problem is that these eruvin are generally constructed using lechis which are some sort of pole (often simply a 1x2 board) attached to a utility pole. The string for the eruv must run over the top of it.

You can see the potential problem with metallic lines in proximity to utility poles from an electrical perspective and mechanically the sheer weight of any wire substantial enough to survive the weather would demand stouter lechis, increasing the cost and difficulty of making the eruv.

The idea of an electronically monitored eruv is attractive at first glance but th problems mount quickly—complexity, cost, and unintended social consequences.

I am not a Rabbi, nor an expert in eruvin, but my (not completely ignorant) opinion is, as I stated earlier: get really good at, and technologically enhance, the normal., required, and effective checking done by people. This is my opinion, and was the result of considering such a project.

Not wanting this to become an off-topic thread, I won’t be responding to it any more.

 

Couldn't you just hang a fluorescent fishing bobber from each span? If the line breaks or gets out of place, it'll be very visible.

I couldn't find a picture that does justice to just how crazy visible these things are. Something like this. If you ever hike along a river, you can easily see these stuck in trees on the opposite shore.

 

Couldn't you just hang a fluorescent fishing bobber from each span? If the line breaks or gets out of place, it'll be very visible.

This isn’t a bad idea, per se, but it is not a problem with visual checking the TS is trying to solve, rather remote checking.

Additionally, generally it is preferable to keep eruvin low profile for various reasons.

 

Ah yes, I glossed over the remote part. Well OK in that case it gets tricky fast, especially without wifi coverage. I'd use a tension sensor - a scale - to tell whether a line is taut or not, and then get that sensor's signal onto a wifi transceiver. Pretty standard IoT at that point. And then the areas without wifi will simply need extenders to fix that. I think that would be easier, cheaper and more versatile than building some sort of alternate radio system.

 

Ah yes, I glossed over the remote part. Well OK in that case it gets tricky fast, especially without wifi coverage. I'd use a tension sensor - a scale - to tell whether a line is taut or not, and then get that sensor's signal onto a wifi transceiver. Pretty standard IoT at that point. And then the areas without wifi will simply need extenders to fix that. I think that would be easier, cheaper and more versatile than building some sort of alternate radio system.

There is actually a thing for this. Along conveyor line often there will be a pull-cord emergency stop. It requires a certain amount of tension to set it, and if the tension goes below a threshold (cord got cut) then it will trip and trigger the emergency stop. Also if the tension goes above a threshold (someone pulled the cord) it will also trip. It is a simple-ish mechanical device with electrical dry contacts. Could be wired to any kind of device.

 

Even though an eruv has no significance to me as a Lutheran, Yaakov, I still found your explanation very educational.
Thank you.

 

This is my project. It has been operating for over a year without an external energy supply. In my case I use a temperature sensor, you replace this with a high precision atmospheric pressure sensor, BMP581. The data is received by The Things Network.

MCU: ISP4520
ENERGY HARVESTER: CJMCU-25504
EDLC: 3.5F/5.4V VEC5R4355QG-I
SOLAR PANEL: 2V/160mA A17052600UX1673

 

Since LoRa consumes much less power than Wifi, it can be operated continuously using only solar cells. The solar cell and transmitter module are attached to a pole, and a rod with a pressure sensor is strapped along a wire.

If the wire breaks, the altitude at which the sensor is installed will drop, and this change in air pressure is monitored by the server. You can use myDevices Cayenne as a dashboard or use IFTTT to alert you.