I'm currently working on a project that requires gathering data from a car's wheel speed sensors(4 hall efect speed sensors). Those sensors are connected to the car's ECU responsible for ABS/ESP/Stability control etc.
In order to extract the data from the ECU i need to make a request with a specific PID(parameter ID) AND know how to decode/compute the answer in order to extract any meaningful data. Unfortunately vehicle manufacturers don't seem to make such information public.
So far i've ordered an arduino CAN BUS shield and a OBD2 to RS232 cable in order to make the physical connection.
I have tried using a specialized hardware/software(that costs more than 1500euro) capable of extracting those parameters, but unfortunately it lacks logging functions. I tried using Wireshark to sniff the PIDs called, but had no luck there either.
If you guys have any ideas, questions or suggestions, please write them down.
I'm open to criticism and know that i might be missing something important.
Thanks.
P.S. This is a university project im working on. I need data samples from the wheel speed sensors and further computing of the data sample is done with the purpose of researching car safety and behavior in dynamic road scenarios.
You can only read the OBD data from the OBD-port. The OBD PIDs are generalized in ISO/CD 15765-5. You probably find non reliable descriptions also in Wikipedia. But in order to get the other PIDs, firstly you should know that those data are heavily under control by the car manufacturers and you have to hack them. One way to find them (but very unlikely to find one!) is the try and error method.
You should access the main CAN-BUS wires and the buy a connector device so you can sniff the packets. then monitor all the packets and make a small change. Monitor it again and compare these two. Maybe maybe maybe you have a chance to find some non-safety features with this method but finding security functionalities like ABS is heavily in doubt.
UNLESS you are some sort of genius hacker who can do weird stuff! If you can do it, then call the manufacturer and show them what you have so you would likely get a nice job and salary by them!
ONCE I saw a youtube clip that a guy could control a TOYOTA (if I remember correctly) with a laptop! and also maybe you can buy such info on the dark web which I advise highly against it!
Related
Can anyone tell me what major and minor (contained within the advertisement packet of BLE signals) are used for? I've heard that it's used for differentiating signals with the same UUID, but that raises questions like "why use two" and "is that just how certain receivers use it". It would be useful to have a decent explanation of it.
As per #Larme's comment, I presume you are asking about iBeacon advertisements - these are a special use of BLE. Bluetooth Low Energy service advertisements have a different format and don't include the major/minor.
The iBeacon specification doesn't say how to use major and minor - this is defined by the people that implement solutions using iBeacon. Two numbers just gives more flexibility.
A lot of effort went into making BLE use very little power. Accordingly the iBeacon advertisement has to be quite small in order to minimise the transmission time. I guess the designers decided two 16 bit numbers was a reasonable compromise between power consumption and a useable amount of information.
A typical retail use case could use the major to indicate a store (New York, Chicago, London etc) and the minor to indicate the department (shoes, menswear etc). The app that detects a beacon can then pass this information to a server which can send back relevant information - the user's location on a map or specials for that department etc. This was discussed in the guide that #Larme linked to.
A solution that presented information on museum exhibits might just use the major number to determine which exhibit the person was near and ignore the minor number. The minor number would still be in the advertisement, of course, the app just wouldn't use it for anything.
I have some old relays that controlls an hydraulic motor.
I want to control it with my Arduino. Is this possible?
The relays used are:
DIL 00 52 from klockner moeller.
this is the situation:
I have experience with the arduino but not that much about electrical schemas?
Is there someone that can help me?
Is this equipment functional now?
The part you have pictured looks like it is for an engine lathe, not a pump.
The amount of rust in the box and corrosion on the overloads and relay would make me think that it has run either outdoors, or in a corrosive environment for quite a while with the door open. Why would you run it with the door open?
Because you have to continually reset the overload and or adjust the timer, or tap on the contacts to get them to engage. Either way, this thing is a mess.
The relays you have shown will interface easily with your arduino, but I WOULD NOT replace what's in the cabinet with these.
The set up in this cabinet is for three phase power. The one on top is the main contactor, and the two side by side units are for reversing the motor. Something you don't want to do with a pump.
My advice to you is to find an electrician before going any further with the power end of this project.
it is possible but probably that relay won't fit the load.
You have to be sure to use relay that can sustain at least the same load and spike current (and voltage), or you many bad thing may happen, like melting togheder the relay contact or burn your house down.
i can't see the code on the relay in the second picture, neiter you had given the load information, so i can't help you more.
I've been thinking about wireless networking a little bit recently, and I came upon a realization last night that I can't find an answer to: how do clients know when they can transmit and not stomp over another clients' transmission?
I assume there is documentation for this sort of thing available, but I've been unable to find anything useful over a half hour of casual Google queries, probably because I don't know the right terms. Apologies in advance if this is a silly question . . .
Here's why I'm confused: based on my understanding of how RF hardware works, we can model the transmission medium as a safe shared register between different RF clients (because what one client broadcasts can be overwritten by other clients and get a muddle between the two). But safe registers only have consensus number 1, so how can we establish who can transmit at any given point? I'm assuming that only one client can transmit at once -- perhaps this is my fundamental misunderstanding?
Even the use of a randomized consensus protocol seems unwieldy, because the only ones I know of use atomic registers, not safe registers, and also have no upper bound, so two identical devices with the same random seed would proceed for a very long time.
Thanks!
Please check: Carrier sense multiple access with collision avoidance
I'm making an application for a running competition on a fixed track. I'm investigating what systems could be used and tough of using a stick containing a GPS/DGPS module and a Zigbee enabled chip to communicate the location to a server.
I've researched the subject (on the internet) but I was wondering if anyone has some practical advice/experience with using a Zigbee mesh/star topology in a dynamic environment wich could apply to this use case. I'm also very interested in using a mesh topology where the data is transmitted (hopping) trough the different Zigbee modules to the server.
Runners are holding a stick; run around the track and than pass the stick on to the next team member.
I am not particularly clear about your goal. But I'd like to say a few things.
First, using GPS/DGPS to measure which team reaches the finish line is inaccurate. Raw GPS data is horrible in accuracy (varying in 1 - 10 meters, well, around that), also the sampling rate of a GPS module is low (say once a second?) How do you determine exactly which team reaches the finish line first?
Second, to use a mobile ZigBee chip to communicate in real-time is hard. I assume your stick has a ZigBee end device. When it is moving (which in your case is pretty fast), it must dynamically find and associate with new parent routers, which takes time and depending on the wireless environment, it might involve several retries. So you will imagine a packet is only successfully delivered to the other end after 100ms or even a second. This might not be a problem if your stick records the exact time when a team reaches the finish line. Since you have a GPS module in the stick so there is no problem in getting very accurate time.
I'm thinking about making a networked game. I'm a little new to this, and have already run into a lot of issues trying to put together a good plan for dead reckoning and network latency, so I'd love to see some good literature on the topic. I'll describe the methods I've considered.
Originally, I just sent the player's input to the server, simulated there, and broadcast changes in the game state to all players. This made cheating difficult, but under high latency things were a little difficult to control, since you dont see the results of your own actions immediately.
This GamaSutra article has a solution that saves bandwidth and makes local input appear smooth by simulating on the client as well, but it seems to throw cheat-proofing out the window. Also, I'm not sure what to do when players start manipulating the environment, pushing rocks and the like. These previously neutral objects would temporarily become objects the client needs to send PDUs about, or perhaps multiple players do at once. Whose PDUs would win? When would the objects stop being doubly tracked by each player (to compare with the dead reckoned version)? Heaven forbid two players engage in a sumo match (e.g. start pushing each other).
This gamedev.net bit shows the gamasutra solution as inadequate, but describes a different method that doesn't really fix my collaborative boulder-pushing example. Most other things I've found are specific to shooters. I'd love to see something more geared toward games that play like SNES Zelda, but with a little more physics / momentum involved.
Note: I'm not asking about physics simulation here -- other libraries have that covered. Just strategies for making games smooth and reactive despite network latency.
Check out how Valve does it in the Source Engine: http://developer.valvesoftware.com/wiki/Source_Multiplayer_Networking
If it's for a first person shooter you'll probably have to delve into some of the topics they mention such as: prediction, compensation, and interpolation.
I find this network physics blog post by Glenn Fiedler, and even more so the response/discussion below it, awesome. It is quite lengthy, but worth-while.
In summary
Server cannot keep up with reiterating simulation whenever client input is received in a modern game physics simulation (i.e. vehicles or rigid body dynamics). Therefore the server orders all clients latency+jitter (time) ahead of server so that all incomming packets come in JIT before the server needs 'em.
He also gives an outline of how to handle the type of ownership you are asking for. The slides he showed on GDC are awesome!
On cheating
Mr Fiedler himself (and others) state that this algorithm suffers from not being very cheat-proof. This is not true. This algorithm is no less easy or hard to exploit than traditional client/server prediction (see article regarding traditional client/server prediction in #CD Sanchez' answer).
To be absolutely clear: the server is not easier to cheat simply because it receives network physical positioning just in time (rather than x milliseconds late as in traditional prediction). The clients are not affected at all, since they all receive the positional information of their opponents with the exact same latency as in traditional prediction.
No matter which algorithm you pick, you may want to add cheat-protection if you're releasing a major title. If you are, I suggest adding encryption against stooge bots (for instance an XOR stream cipher where the "keystream is generated by a pseudo-random number generator") and simple sanity checks against cracks. Some developers also implement algorithms to check that the binaries are intact (to reduce risk of cracking) or to ensure that the user isn't running a debugger (to reduce risk of a crack being developed), but those are more debatable.
If you're just making a smaller indie game, that may only be played by some few thousand players, don't bother implementing any anti-cheat algorithms until 1) you need them; or 2) the user base grows.
we have implemented a multiplayer snake game based on a mandatory server and remote players that make predictions. Every 150ms (in most cases) the server sends back a message containing all the consolidated movements sent by each remote player. If remote client movements arrive late to the server, he discards them. The client the will replay last movement.
Check out Networking education topics at the XNA Creator's Club website. It delves into topics such as network architecture (peer to peer or client/server), Network Prediction, and a few other things (in the context of XNA of course). This may help you find the answers you're looking for.
http://creators.xna.com/education/catalog/?contenttype=0&devarea=19&sort=1
You could try imposing latency to all your clients, depending on the average latency in the area. That way the client can try to work around the latency issues and it will feel similar for most players.
I'm of course not suggesting that you force a 500ms delay on everyone, but people with 50ms can be fine with 150 (extra 100ms added) in order for the gameplay to appear smoother.
In a nutshell; if you have 3 players:
John: 30ms
Paul: 150ms
Amy: 80ms
After calculations, instead of sending the data back to the clients all at the same time, you account for their latency and start sending to Paul and Amy before John, for example.
But this approach is not viable in extreme latency situations where dialup connections or wireless users could really mess it up for everybody. But it's an idea.