I'm working at the mine on the drill machines. I've been given a project to find a communication system that can interface magnetic pickup sensor (MSP6744) with a redlion conveter (IFMA0035). It has to be a wireless transmitter and receiver. We are measuring speed of the rotating rod (rpm) on the gear teeth of the powerhead or gearbox by magnetic pick up. The sensor produce small voltage and max frequency of 1850Hz. This will be converted to 0-5volts then is send to control system.
I've been searching on google and contacting many companies but no luck.
I did my research and found one of the possible solution is to design it using ESP32 but i need lot of guidelines on this one.
Magnetic Pickup Description: A magnetic pickup is installed over a gear and as the gear turns the pickup will create an electric pulse for each tooth on the gear. These pulses are then read by the instrument which interprets it to indicate the correct RPMs or speed.The signal from the magnetic speed Sensor, teeth per second(HZ), is directly proportional to rotation speed.
Related
I'm a developer for different mobile and backend systems and pretty new to network and hardware stuff. I want to build a system/network with 6 cameras placed 100m away in the field, which I want to control with a web interface. I know how to build such interfaces, but I have no clue how to connect the hardware. I thought about the following:
I need 6 cameras(*infos added below) standing side by side with ca. 1.5m space between. These should be connected to a switch, so a 100m wire (USB or LAN, I prefer LAN) goes to a RPI which can setup the web interface controlling the cameras like ".../whatever/camera-slot-ip-or-number".
As I said in the introduction, I have no clue how to start, because actually webcams using USB as a std, but does they provide wake on LAN features? Or is it better to do it with 6 USB-cams and several RPIs?
I hope someone with a better hardware understanding can help me.
Thanks a lot
Specification for the cameras:
HD is not needed, but it should recognize a 0,5cm round hole in a 50x50cm area properly. The distance between camera and object is 7-10m A color image should transmitted, but there only 2 main-colors.
EDIT:
draft 2.0:
Piping USB through a 100m cable is not easily going to work.
Some models of USB cameras can be used with the Raspberry pi, but the performance (speed of taking a picture, and image quality too) are better with the 'native' raspberry pi camera.
The Pi also has a built-in H.264 video encoder, so you can stream live video with relative ease if you want to. A quick and brute way of doing that is to pipe the output from the built-in raspivid application to your own application that then handles flow control and pipes the data further to a socket.
If wifi does nto work for you, then you could pick some other raspberry pi model with an ethernet interface and go that way.
Also, the cost of additional Raspberry Pis (especially the zero w) is so low that the easiest and most cost efficient thing might just be to one raspberry pi camera on 6 raspberry pi's. If connecting them with Wifi works in your application, you can use the Zero W model and then you just need to feed power to them via cable.
Thank you for the updated information. I am pretty much in agreement, I think, with Sami's answer but wanted to add a few more details that are a bit big and unwieldy for a comment.
If you look across the top of your diagram, you have 6 stations at 1.5m intervals, so the width of your diagram is 7.5m. That is easily within wifi range so I am thinking a wifi access point on any of the 6 stations and a 100m Cat 6 Ethernet cable down the length of your diagram to the front-end.
As your processing doesn't sound too involved, you can likely get away with just a Raspberry Pi Zero W and a v2 camera at each station and save a fair bit of money vis-à-vis Raspberry Pi 3B+.
One thing that does concern me is looking for 0.5cm from 7-10m. The lens on the Raspberry Pi camera is pretty wide angle and a 0.5cm hole is going to be awfully small at 10m in a wide angle shot unless at very high resolution. I haven't done the maths, but I think you will be looking for a telephoto lens if such a thing exists... the maths now follows.
The horizontal field of view (FOV) of v2 camera is 62 degrees, so half that is 31 degrees and the camera is 1000cm away. So:
tan(31 degrees) = half the FOV width / 1000
So, at 10m you will get 1200cm of stuff across your image and that will be imaged by 3,280 pixels on the sensor if you shoot at the very highest resolution. So, each pixel in your image will correspond to an area 0.3cm wide whereas you are looking for holes 0.5cm wide - so it will be pretty marginal as to whether you can make it out... maths is subject to revision after a glass of wine later.
We are trying to set in place a system of indoor localization based on BLE Beacons. The precize location of the client does not really matter, the valuable information is the room he is in.
The building to be equipped has large concrete walls. We thought that using one beacon per room, we could detect the closer beacon to the guest.
Are concrete wall able to stop most of the BLE signal? We tried some tests, but we are searching for serious studies.
Any wall will reduce BLE signals by some amount. A signal of -50 dBm on one side might be -60 dBm on the other side, a reduction of 10 dB. Because decibels are logarithmic, every 10 dB reduction in the signal level represents a loss of 90 percent of the power in the signal. So while it is typically true that a concrete wall will "stop most of the BLE signal", it doesn't really matter because there may still be enough signal on the other side of the wall to detect the beacon.
How much of a reduction in signal level there is depends on thickness of the wall and other materials in it (metal will increase the attenuation.) Of course, windows, doors and other breaks in walls provide other paths for the signals to travel and complicate the issue.
Since you are unlikely to create a system where signals from beacons in one room will never be detected in an adjacent room, your best bet is to use other algorithms. For example, you may detect all visible beacons in a time interval, determine which has the highest signal strength, and if above a certain threshold, use this as an indicator of which room you are in.
Imagine I'm standing in a large room that has a router in the corner. Now I'm holding my iPhone and I start moving around in the room.
Is there a way I can track my movement inside that room using as static reference that router?
Imagine I take one or two steps to the left. Will such a small change in location be captured accurately under such conditions?
Do I need more than one hotspots in order to find my precise location inside the room?
Can the tracking be precise since we're talking about movement inside a room and not out on the streets?
If you're interested in tracking physical movement of the phone using a single wireless router as a point of reference, no, it's not going to work. It's defiantly not going to give you a foot or two of resolution, either.
You'd be using the wireless signal strength as a position indicator. However, you'd need two signals (two static points) minimum to give any sort of triangulation. Furthermore, signal-strength triangulation is really, really imprecise - the Wikipedia article gives a network-based tracking a resolution of around 50m. Handset based tracking uses both GPS and signal strength to give a better resolution, but it's still not within a foot or two.
To get good position tracking, a signal is timed between the source and receiver, then triangulated. This gives quite good resolution - Wikipedia articles on "Trilateration", "Time-Of-Flight", and "Multilateration" would give a decent overview of that kind of system.
Long story short? No, you can't get a physical position using a single static router as a point of reference with any degree of accuracy, or precision.
I think you're misunderstanding how Wi-Fi based location tracking works. I'm not sure about the exact process but if I'm right, it involves your IP address assigned by the hotspot you're connected to. And the accuracy of Wi-Fi based location is not as accurate as the degree (a couple of feet to the left or right) you're referring to.
No matter where you are in that room, or even in the same building connected to that same hotspot, your location is going to be reported as the same place.
So to answer your question, NO, the tracking cannot be precise. If you're using you're using the GPS component of your device, that's a totally different story.
I am just looking iphone apps at apple store, and i have found this app g8, http://www.dynolicious.com/, but can you give some ideas or logic that how this app works, i mean how it is possible to measure car performance without using or communicating with any external hardware ...??? By using just hardware built into iphone, ie. accelerometer.
It works as follows. The data provided as results are actually estimates, not absolutely correct values measured attaching external hardware to the car. The estimates come from the GPS unit and the accelerometer embedded within the iPhone. Using the GPS you can estimate from the positions detected in different temporal instants the distance travelled and therefore the velocity. Then you can also estimate the acceleration using the accelerometer.
This is just a guess, but I would expect that you tell it your car make and model which will give the manufacturer's performance and fuel consumption figures. Then using the accelerometer and positional information in the phone you can calculate the speed of the car. A relatively simple equation can then be used to calculate the expected performance.
I would guess it uses the GPS to measure the 0-60 acceleration (start a stopwatch and stop when GPS says you're moving at 60 mph) and the built-in accelerometer to detect G-force. The horsepower estimate is just that - an estimate. They may have a performance table of various known cars and their 0-60 performance and horsepower. Based on that, they can give an estimate for yours.
Is there is a way to determine an iPhone's exact location (indoors, and to a distance of just a couple of feet) via use of radio/antenna's or some other infrastructure located around premises (i.e a hospital, shopping mall, school). Will appreciate any ideas/direction (technologies, research) as for how to overcome this limitation.
If you mean for an area you have control over (setting up a location network for a specific school/hospital) as opposed to generic location, you'd be able to triangulate your position based on wifi signal power for APs with known locations.
If you wanted it to be a generic solution, and you know there would be multiple APs in/around the buildings you wanted, you could triangulate all wifi signals while you have GPS outside the building, and then reference those locations when you lose gps accuracy. The first part is something that many wardriving applications already do.
Here's an article describing a commercial technology for this purpose in high-level detail: link
And here's a link to a SO page where people have started discussing possible methodologies: link
Use the GPS and hope that you got good coverage.
Other than this, you can deploy several wifi hotspots that can measure the signal strength for each packet and do a triangulation to calculate the iPhone position with regards to three or more of these hotspots based on the signal strength each of them measured.
A quick search for "signal triangulation" on the internet reveals a Wi-Fi Based Real-Time Location Tracking technology from Cisco. I have not used it, so I can't vouch for it; and I suspect it's rather expensive. There might be other solutions as well.
The alternative would be to buy several wifi routers or access points and flash them with your own version of the firmware. You can probably use OpenWRT or DD-WRT as a base for this.