How to troubleshoot CAN bus communication - can-bus

I am trying to connect ICP CON i-7565 (USB<->CAN interface) to a custom made device (supporting CAN2.0B, proved to work with PCL-841 card) Although I think I have configured BAUD and acceptance code/mask correctly I can see CAN no messages coming from the device (ICP provides a tool that should allow me to send and receive CAN messages).
I am new to CAN bus so I appreciate any help regarding how to identify the problem.
I-7565 might be wrong interface for me, I might have misconfigured it, or it is simply broken. Or I am just doing something wrong out of my ignorance. I don't think anyone can help me with my specific problem, so I am rather asking for general information on how are problems with CAN bus identified and analyzed. In TCP/IP for example, you would call ping, you'd recheck your ip and gateway settings etc. What do you do for CAN communication?
Additional info:
OS: Win7 64bit
connector: DB-9 with standard wiring (2,3,7)

Finally I tried to work with different USB<->CAN interface from different manufacturer and it worked like a charm. My old interface was either broken or incompatible for reasons unknown. While working on this problem I learned couple of things about CAN bus and so now I share what I think was the right answer to my original question: How to troubleshoot CAN bus communication?
read manual to your USB-CAN interface
install driver of your interface device and make sure it is working (check device manager, depending on the type of your device you will see new COM port added or new USB controller )
your device should be shipped with it's own test/analysis software (they might call it utility or similar), run it and check if it can connect to your device
CAN communication uses three wires that are referred to as High, Low and Ground and is usually connected with DB-9 connectors where High is linked to pin n. 7, Low to pin n. 2 and Ground to pin n. 3 or 5 - make sure this is connected correctly on both your USB interface and CAN device you want to communicate with
set properties of your connection, these are most of all: CAN type (2.0A or 2.0B) BAUD rate, Acceptance Code and Acceptance Mask
if you've done all of this and still you can see no CAN messages arriving in your utility program, check with a different USB-CAN interface or find some other way to test if your device is actually emitting CAN messages and your USB interface is in fact able to receive them. (this was actually my case)

Related

Does iOS MultipeerConnectivity provide routing layer?

I am writing an app that is suppose to work without a connection to mobile carrier and without local WiFi. Each device will act as transmitter, receiver and router.
My main challenge so far is that I cannot figure out how exactly MultipeerConnectivity works as documentation on MC is really limited. Apple denied revealing technical specification of MC claiming it's a proprietary network stack, so I have to rely on network sniffers and reverse-engineering which is not the quickest way to figure out how MC works.
Suppose I have 100 devices forming a mesh network in such way that each device is within the range of at least one other device and at maximum three other devices.
Is there any way to send a message from node A to node B that is not within the range of node A without the need to broadcast the message to all other nodes? I mean that message should be properly routed through all other nodes.
Does MC include a routing layer too or I have to write it myself?
From what I can see ad hoc delay tolerant wireless networks is still a hot subject in research.
These slides on ad hoc delay tolerant wireless network shed more light on the subject as it was a few years ago. And also this paper. Has Apple progressed it much with MC?
I cannot really see any way to send a message between nodes not directly connected to each other without flooding.
Correct?
The MCSession Reference states that
Sessions currently support up to 8 peers, including the local peer.
Also, the overview you cited says
In the discovery phase, your app uses a browser object […] to browse for nearby peers[.]
Moreover, the documentation on managing peers manually suggests that all peers in a session must be connected with each other to have them in a session.
This is suggesting that the framework only covers the communication between nearby devices, as in 'reachable by bluetooth or WiFi'. Naturally, those devices do not need complex routing, as they do communicate with each other and the benefit of the framework is simple multicasting between nearby devices, from a programmers' point of view.
As far as your question goes, this is about it - trivially, since all peers an a MCSession have links to each other - there is no routing needed.
This does however, allow you to construct a routing layer pretty easy.
Given your scenario, there will be multiple MCSessions with devices being part of at least one. All devices that are part of more than one MCSession do become routers and interconnect the MCSessions with each other.
The rest of the task should be straight forward; defining a namespace for addressing devices and implementing a routing protocol of your choice.
The old days of the internet, with unstable dialup connections, might be a plus factor for you as the routing protocols in place are rather stable in regards of link loss.
Here are two good starting points for you to make your choice of better fit:
Link state routing
Distance vector routing

looking for alternative solution than IPFW for slowing down an internet connection

I need to slow down (simulate bad) internet connection, I found some documentation where it was achieved by "ipfw pipe" command , the thing is that in latest MAC OS versions , ipfw was deprecated (and removed)...
I was wondering if there are any alternative to the ipfw API ?
Does anyone know how latest Network Link Conditioner achieves it?
The original previous way which enabled to slow down an internet connection :
sudo ipfw pipe 1 config bw 56Kbit/s delay 200 plr 0.2
and to clear the pipe :
sudo ipfw delete 1
Thanks.
I don't know much about Mac OS (I use Linux myself), but I'll give this a shot.
A bunch of digging established that ipfw seems unavailable, as you say.
I was also unable to find a way to use the Network Link Conditioner from the command line. Everything should be usable from the command line, so that's stupid.
One work around would be to try to access the NLC from within AppleScript. The following will get you started on toggling the NLC:
property thePane : "com.apple.Network-Link-Conditioner"
tell application "System Preferences"
activate
set the current pane to pane id thePane
--delay 2
end tell
---
tell application "System Events"
tell application process "System Preferences"
try
click ((checkboxes of window "Network Link Conditioner") whose description is "enable switch")
on error
click ((checkboxes of window "Network Link Conditioner") whose description is "enable switch")
end try
end tell
end tell
I think that you can run a script from the terminal with osascript <SCRIPT>.
As an alternative, Charles Proxy is a pay-to-use program that can be used to perform throttling, provided you can convince the software you are testing to connect to the proxy's port rather than directly to the internet. Maybe there are free proxy solutions out there somewhere?
Perhaps Squid would work in that regard. SquidMan seems to be an easy-ish way to install it for Mac. It looks as though DelayPools and or Client Bandwidth Limits might be useful for simulating a low speed connection, though I can't find evidence of people having used them for such.
I found several solutions that might work. They come from some old threads, but they might help:
How to simulate slow internet connections on the mac
Apple has made a very handy official tool to slow down the network connections on you Mac for testing purposes.
The Network Link Conditioner preference is a free download from within Xcode (for Lion and later OS). Additionally, iOS has similar function accessible from within Xcode and iOS 6 or later.
How do I simulate a bad Wi-Fi connection on my iPad?
There are a few ways you can do this, depending on your situation:
Move further away from your router. While this may seem a bit obvious, I realize that it isn't always possible while testing/debugging (for example, if you are working on a desktop computer).
Put aluminum foil around the router and/or antenna. This will (partially) block some or all of the radio signals by creating a makeshift Faraday cage. The results you get will depend on the strength of your router signal, distance from the router, and other environmental factors.
Set your router's wireless signal power to a lower setting. The method for doing this is different for each router, so you will have to look at the user guide for instructions on how to do this.
Slow down internet for iOS simulator
You can set the network to slow characteristic by testing on devices. Go to Settings -> Developer Settings -> Network Link Conditioner -> Enable. This is for iPhone/iPad running iOS 6
I don't know if the last one you can still do.
I've used many methods in the past for slowing down network connections, among them:
performing a parallel download of some massive Linux ISO file;
physically pulling out the Ethernet cable (at one point, I actually toyed with the idea of building a push-button device that would sit between two cat5 cables and do this without having to physically disconnect the whole cable).
using ifconfig eth0 down ; sleep 1 ; ifconfig eth0 up.
Hopefully one or more of those methods will help.
If you're looking to slow down your network connection because you're doing testing/profiling work, one option is to get a specific device that can create network latency/noise.
For example Apposite Tech's mini2 WAN emulator allows you to change values for bandwidth and packet loss. You can roll your own device too using something like: http://wanem.sourceforge.net/ . It just depends on your needs, time and budget.

How to monitor packets using Snort features?

I want to create a network intrusion detection system for iOS application. The main function is to allow the user to select a home network (maybe prompt them to simply enter the IP address only) and to be able to monitor the packets and if there is anything suspicious- we need to alert user via push notification or email. i wanted to use the features and functions of Snort, an open source network intrusion detection system.
Any Suggestions,Sample code ?! Where to start?
VM's do not have native hardware access, which is necessary for monitor mode. Maybe IOMMU PCI passthrough or bridged devices might work. It is probable that it is possible to compile the iOS kernel with a module that works for the wireless nic. I don't think it's a proprietary chip specific to apple, because a chip with multie technology capabilities in RF wouldn't be cost effective qt all. I'm just not sure if the filesystem blocks access in the OS framework or whatever. I have tried to compile linux/iOS ARM packages natively in the shell with the aircrack-ng source, but have not had any luck. Maybe someone would have better luck actually cross-compiling a package and sideloading it somehow.
I don't think this is possible for multiple reasons:
You wouldn't be able to compile snort for iOS.
In order to run snort you have to have the interface (NIC) in promiscuous mode, which I really don't think you can do on an iOS device (iPhone, iPad, etc) but I have never really looked into it, but Apple probably locks this down and restricts this for security purposes so if you could do it you'd likely have to jail-break the device first. It's not even possible to put the wifi card in an Apple laptop into monitor mode, which is similar.
There are a lot of dependencies for snort, most importantly the DAQ. You would probably only be able to monitor the wifi interface (even this might not be possible), not the interface used for the cellular network as this is probably a different daq than standard Ethernet nics.
This very likely is not possible on iOS, if it is it would be VERY difficult to pull off and even if you did the use case isn't really good. Even if you could get a daq for the cellular card, I don't know if promiscuous mode even exists and if it did all of the traffic on the cellular network is encrypted, so inspecting this with snort would be pointless. If you could do it for the wifi traffic it's probably not worth the effort honestly, especially since almost all traffic nowadays is encrypted, you'd have to decrypt it first, which certainly isn't possible to do.
In the view of Johnjg12's comments, I am wondering about your goal. If you want to make a NIDS, you can make it OS independent, anyway. If you want to consider only HIDS that monitors packet destined to it, we don't need it to be in promiscuous mode (a comment to Johgj12's response). so, now it is something to do with Snort on iOS. I am wondering if we can do it on a VM and then turning its promiscuous mode? Having said that I came across a link: https://www.securemac.com/macosxsnort.php

How can I access a game controller via USB?

Problem
I am working on modifications to one of my applications that communicates with a telescope.
One of the most annoying problems due to nothing else but reckless poor design, is the GOTO controller and its keypad.
If anyone of you remember the Sinclair Spectrum you know what I mean. As well as the rubber keys, the crucial keys for guiding and slewing the telescope are awkward to locate when your eye is trying to adapt to the view.
All it takes is the wrong key and you spend another 30 minutes or so re-aligning the telescope.
Workaround
My solution is a game controller such as a wingman, it fits neatly into your hands and is easy to locate the buttons. Also there is no risk of reseting the mount.
Question
My question is this, how does Delphi interact with game controllers because tthere is no mention in the documentation? Otherwise how do I access a gameport when it is connected through a USB dongle?
Working with the game controller is part of the Windows API. JEDI's JVCL has a Human Interface Device (HID) constroller (TJvHIDDeviceController) component that does what you want.
Delphi applications running on "NT" line operating systems (NT, 2000, XP, Vista, 7, 2003, 2008...) can't access hardware devices directly. Only drivers can, because the I/O ports required to access them can be accessed only by code running at the right IOPL level (which is 0 in Windows). There are some generic drivers available that open any I/O port (thus creating a security hole) that user code can call.
But tt's far better to rely on device drivers, and use the HID API to interact with them. Windows will recognize most older devices (like the serial/game port Wingman), while newer USB ones or use the standard drivers that come with Windows, or come with their own. Once the system recognizes the devices, you can use them in a standard way with no need to dig in the low-level details.

iOS virtual button to Arduino

What would be the best way of sending a signal from an iPad to an Arduino?
I am trying to use XBee, with iPad and Arduino to send a wireless signal.
I want to make a big red virtual button on an iPad that, when pressed, turns on an LED on the Arduino.
I am a total newbie when it comes to iOS, but OK with Arduino and XBee.
So I'm not sure if I understood correctly, but in my meaning there is only one simple way to solve the problem:
Connect an XBee to a Computer and another to the Arduino. On the computer you launch a webserver, which will be accesible from the iPad over Safari. This server handles the clickes and writes to the XBee Com Port, for communication.
Here are some examples, people already made:
http://www.projectallusion.com/1/post/2009/11/iphone-controlled-solar-powered-arduino-tank.html
http://www.sparkfun.com/tutorials/152 (not with xbee, but you can implement that by yourself)
I know it's been a while but I just came across to this question and yesterday I was doing the exact same thing so I'll share the method I used and the source of it.
In order to set a LED on or off in an Arduino board from the iPad you really don't need anything more than a browser. This is of course if you have a way to connect that Arduino to the local network.
Today you have at least two options. The WiFi and the Ethernet shields. Once you have your Arduino board inside the network you can send the instructions (HIGH or LOW) to the board form the browser.
These are my two boards connected waiting to be plugged to the local network:
Of course, you'll have to code the board to process those instructions. There are many examples on how to configure network settings and state instructions:
If you have a bit of time and want to do something more elaborated you could create a simple app to graphically control the state of those LED(s).
Inside you'll basically do the same thing, create the URL command and send it to the Arduino IP but it'd look much nicer. If you integrate later more controls the sky in the limit.
My experiment is a combination of what I learned from this nice tutorial and some tips I've read here and there.
I hope it becomes also useful to someone else.
Cheers,
Since you need to use a network connection from the iPad, a possibly simpler way to do this would be to use a WiFi module on the Arduino to poll a web script, and have the iPad write a state (button press) to that web script.
There's a handy WiFi module called the RN-XV that's designed like an XBee. I wrote up two tutorials on it:
http://log.liminastudio.com/programming/getting-started-with-the-rn-xv-wifi-module-node-js
http://log.liminastudio.com/itp/physical-computing/using-the-rn-xv-wifi-module-as-a-remote-switch

Resources