I have a client that is the owner of a farm. He wants to get monitorized the 1000 cows he has at a field. Mainly,he wants to identify the cows individually and checks to place a tablet near a specific door and check which o them crossed the door. Is that possible? I mean , the bluethoot receiver is able to read as 50 cows crossing simultaneously the door?Or it overflows the capacity of the technology? How the system needs to be configured ? The tablet as server and de bluethoot low energy devices as clients?
An explanation will be much appreciated
I'm not sure if Bluetooth is the right technology for that. Even if the Tablet can handle that many connections simultaniously, it does not tell you anything about the position of the animal. Basicly it would detect anything in a certain radius, but you wouldn't know if the cow passed through or just came close.
To answer the Client-Server Question: The Tablet acts as the "Central" device, the BLE sensor is a "Peripheral" device. Depending on the Application both device could act as server or as client. Here: Introduction to BLE you can find a Brief Introduction to Bluetooth Low Energy with more Details.
Depending on the gate size, NFC could be a better choice.
Related
My professor recently approved our research paper which will also be used in our final year thesis. Basically our main purpose is to create a system for location tracking and attendance automation for students and staffs. We would like to use the power of bluetooth low energy modules for this project.
I have actually done quite few research about this but I am having trouble which keywords to use in order for me to filter the right answers for my question. So instead, I'll just put all my questions here.
I provided an image to further understand the concept I am talking about.
Basically, the broadcaster/advertisement mode modules are for students and staffs. While the observer mode modules are initially installed in every rooms or spaces in our building/campus.
Broadcast and Observer mode
I would like to clarify first that the location tracking is only basic, it only detects which rooms are the students and staffs located.
Here are my questions:
What is the maximum advertisement/broadcaster module can the observer module detects at the same time?
Our target is about 50 students per room, 300 students in cafeteria, will the observer module have a large amount of latency upon scanning advertisement packets?
Do we have to use different module for observer mode, or will the same module for broadcaster mode be just fine?
Since this is supposedly embedded to school IDs, we would like to use a coin cell battery, how long will it last?
According to my research, BLE range is about 100 meters, but we will be using coin cell battery, is it really possible to achieve 100m for broadcasting and observing? If it is, can we perhaps decrease it by programming?
My apologies for too much question, as this is actually our first time doing applied hardware stuffs due to pandemic. Most of our laboratories are basically tinkercad base. Face-to-face classes are allowed for only medical students for now.
A few answers:
BLE scanners can detect hundreds of distinct broadcasters at the same time. There is no hard limit, but the more broadcasters the longer it will take the scanners to detect each broadcaster.
Most BLE modules support both peripheral mode (broadcaster) and central mode (scanner) simultaneously.
Scanning 50 broadcasters in a single room will easily detect 90% of packets, so if the advertiser is going at 1 Hz it will usually take one second to detect, but sometimes 2-3 seconds of packets are missed.
The indoor range is closer to 40 meters with no walls obstructing the signal. Outdoors with clear line of sight the range is higher. Walls often block signals almost entirely, depending on materials.
A CR2032 coin cell can power a BLE broadcast at 1 Hz and max power for about 30 days.
Creating an embedded solution is cool and valid but just remember that broadcasters already exists as each and every student carries a smartphone with BLE embedded into it and your observer can be any BLE capable device from smartphone through PC with BLE dongle all the way to Arduino and alike.
Your broadcasters (or BLE peripherals as they should be called) will need an Android / iOS app and you will have to deal with working in the background without the operating system stopping your app.
Your observer (or Central in BLE language) can be any stationary PC if such exists in the class which can make development and deployment a lot easier.
I'm reading so much propaganda about BLE beacons (Kontakt.io, in my case) being accurate to the centimetre, readable at 70 metres etc etc, but my experience has been nothing like that.
I have 3 beacons. If they're in the next room over (door open, around 6 or 7 metres), it'll detect maybe one or two, after around 20 seconds. Even then I often need to restart my app over and over to detect it.
Move them to the same room, and they're pretty much okay. Everything's default, scanMode is 'LOW_LATENCY', scanPeriod is 'RANGING', I'm not sure what else I can do.
Do these results sound way off, or are they just not that good?
A few tips about Bluetooth beacons in general, not specifically Kontakt beacons:
When you need to restart your app to detect beacons, that clearly means it is something on the phone, not the beacons themselves that are the issue. That issue may be the app, the SDK, the Bluetooth stack on the phone, or the phone's bluetooth hardware. Try an off the shelf detector app like BeaconLocate for iOS or Android and also test with a different phone.
The range of a beacon is dependent on its output transmitter power, typically measured at 1 meter. This output power is adjustable on many hardware beacons and is often set lower than the maximum to save battery on battery-powered models. For best detection results, set the output power to the maximum that configuration allows. An output power at one meter should be at least -59 dBm for best results. Less negative numbers mean more power. Because some phone models have poor sensitivity and measure RSSI inaccurately, you may want to measure with different models. In general iOS models are more predictable receivers.
The range of a beacon between rooms varies greatly depending on materials in walls, furnishings, and local geometry. A beacon with an output power of -59 dBm at one meter can be reliably detected by a phone with a sensitive receiver at 40 meters away, but only with clear line of sight conditions (typically outdoors). Intermittently, I have seen such beacons be detected outdoors at over 100 meters away. Intermittently means that 99% of packets are lost, a small percentage are successfully received.
Always be skeptical of marketing claims from companies trying to sell you something. The above points should tell you what is achievable from an independent engineering perspective.
So I will have more than 40+ devices in one place and I need to record when device entered in my zone and also when i lost signal by BLE.
As i know there are only 20 regions limit in IOS in one time.
As i can't set regions on peoples devices , is it means that i can't track more than 20 devices or is there any way to do it?
Devices will be iPhone,apple watch , androids.
So i guess they will have different UUID.
You are right about the 20 beacon region limit on iOS, but that probably will not impact your solution for a number of reasons:
The limit is per region not per device as #paulw11 says, so you can track much more than 20 beacons if you define regions that match multiple beacons by using wildcard idebtifiers in the regions.
You cannot make an apple watch transmit as a beacon. And while iPhone and most Android devices can do this, iPhones must have your custom app in the foreground to transmit. This may not work for you depending on your use case.
An alternative to having the devices transmit is to have them receive a beacon signal from a fixed beacon transmitter you install. This can be done by a custom app in the background (although for Apple watch it must be tied to a nearby iPhone for this to work). With this approach, there is no limit to the number of devices you can track. This is the typical way this is done.
I have this GSM embedded device under linux, where depending on external factors I might chose to put a different sim card into. But in the configuration for the PPP, I have to give an APN, which changes depending on the network du jour. How can I automatize that?
It just downed on me that smartphones don't need explicit APN entry to work when changing the sim card (also, the APN is sometimes different in M2M and actual cell phone, not sure I can use the same trick).
(I know you are curious: it's deployed in the middle of nowhere, and we chose the least worst network at the last minute on the installation site)
You can detect the network operator from the IMSI of the SIM, and have in your device a table mapping operators to APNs.
There are several sites that will provide you an IMSI to operator listing or MCC and MNC to operator listing. The MCC (Mobile Country One) is the first three digits of the IMIS and the MNC (Mobile Network code) the next 2 or 3 digits. Some example links:
https://www.imei.info/carriers/
https://www.mcc-mnc.com
As an aside, if you want to be able to change to adapt to the best available network coverage over time, the way many M2M applications achieve this is to use a 'forgein' SIM which can then roam to the best available signal at a given time. If your data usage requirements are low this can be a good way to avoid being dependent on one operator in an area with poor coverage. There are quite a few companies who specialise in these type of M2M sims, depending on your target location.
I have a friend who is working on a project where they need to deploy a large number of devices over the midwest. For simplicity let's say these are temperature gauges - they read the current temperature and transmit that information to a server. The server would just need to know what device is reporting what temperature (412X|10c).
These devices will be in forests, near highways, in cities and swamps. All other technology is prototyped and working (ability to read the temperature, the hardware for the device) the open question they have right now is 'what is the cheapest way we can send this information to the primary server'?
I think they'll need to go with a wireless carrier (verizon/sprint/at&t) and use something similar to mobile broadband. Is there really any other option?
You could do it with ham radio and something like APRS, assuming they don't care about encryption and don't have a pecuniary interest in the project.
You wouldn't need full mobile broadband, as your data would fit in a text message. You can get cellular shields for arduino that would probably fit your needs.