I am currently running a robotic's project using an Hokuyo (URG-04LX-UG01 - http://www.hokuyo-aut.jp/02sensor/07scanner/urg_04lx_ug01.html). This one is plugged to my computer using USB. Although it creates the port "/dev/ttyACM0" when I plug it, I can't connect to it using the associated library (serial connection error). Until here, nothing's strange, bugs or misprogramming happens but here is my problem :
When I plug the hokuyo to an USB HUB, which is also plugged to my computer, I can connect to it and everything works perfectly.
My laptop is a samsung 900x3c running Linux Mint 15.
Do you know what an USB HUB changes in the USB communication ?
Is there a link with my laptop ? (I used to face the same problem using an ARM-Based embedded computer)
Is it possible to fix the issue without using any hardware solution ?
If it's not, is there anything more compact than an USB HUB which could fix it ?
Thanks !
Is your USB-HUB powered from external power adapter? URG-04LX-UG01 seems to consume 2,5W/5V=0,5A. This is limit for USB. Laptop USB ports are not so powerful and if device consumes a little bit more than max, then they just cut the power.
Update
The device is USB 2.0 Full Speed. I've seen USB controller, that had problems with USB 1.0 or USB 2.0 devices. Hub presents itself as USB 2.0 High Speed and handles USB 2.0 Full Speed transparently for the Laptops USB controller. Do you have another Laptop/PC to check this?
I'm kind of late on my feedback for that issue, but better late then never so :
I've been able to determine that the whole issue came from my USB cable. Somehow there was an electrical issue in that cable and the computer-or the hokuyo- was not able to properly communicate through it. I think that the USB HUB was somehow able to correct theses electrical issues.
Anyway, problem solved !
Related
Is it possible to send an ASCII code on an external device through USB port using IOS API? I assume that it is possible through bluetooth connection, but I'm not sure through USB connector. Any thoughts?
I would appreciate if someone could put me in the right direction.
Thanking you in advance
That largely depends on the level of sophistication of this "external device". If this external device is just a bare metal embedded device without some sort of operating system you definitely need MFI.
Otherwise, you can run a usbmuxd server (e.g. on Raspberry PI with Linux) to establish a connection via USB. Usbmuxd is basically the technology that Apple uses to communicate between iOS devices and Desktop apps such as iTunes or Xcode. And yes, it is App Store compliant, e.g., Duet Display uses this approach to make an iPad a secondary display for your Desktop via USB.
There are several open source libraries that provide a high level API, e.g., PeerTalk or DarkLightning.
We have an application which is intended for intranet use. It's not available on the web and we'd prefer to keep it that way.
In house the iPad can connect to the wifi and we can demonstrate the website that way. At a customers is there any way of connecting the iPad to the laptop and showing a website running on IIS off that laptop?
The only way I can think of is by attaching a router to the laptop and running a local network that way, not sure if customers would be entirely comfortable with that
We could also look into some kind of VPN arrangement? It would be so much easier if we could connect the iPad and laptop though
thanks
(Edit) Is Bluetooth a possibility?
I did a huge kludge when I needed something like that. I don't really recommend it because it's annoying, but it works to some level.
Connect your phone to the laptop, sharing the 3G connection via USB.
On the laptop, share that USB connection via WiFi.
Connect the iPad to the laptop's access point (WiFi)
The iPad should now be able to "see" the webserver that runs on your laptop
I am looking for a weekend project to do and I was wondering if this was possible. I have these radios that are programmed using Telnet (to set the frequencies, output power, etc.) and I normally do this with my computer in the terminal. The radios have an RS-232 connector on them and I use a USB converter to connect to my computer. Having a small, portable device to program them with instead of a big, clunky laptop would be great, so what I am hoping is possible is to be able to create a telnet connection with my iPhone. Is it possible to create a Telnet application for my iPhones that can connect to these radios through the USB/lightning port on the iPhone? I know normally when people write Telnet applications for the iPhone, they are using over the air connections like WiFi/3G/4G to connect to the internet, but this radio is not connected to the internet but its own private network of other radios. If it is possible to connect the iPhone to the RS-232 port and accomplish the Telnet connection (also without frying my iPhone with too much current) that would be fantastic. Also, if it is possible, how would I access the lightning port? Thanks!
EDIT: Another possible connection is the iPhones lightning port to an RJ-45 connection. That would work as well. Is this possible? Thanks!
As far as I know, you can always study the specification of the lightning connector, you can find it here : http://en.wikipedia.org/wiki/Lightning_(connector). You can try to play with the SDK, trying to send commands from the iPhone and receiving information through the cable. The problem of that, and I was working in several medical applications with the 30 pin connector and the lightning as well, is you have to spend a lot of time to deal with the specification. The most important part is to understand how the connector works and what can you send and receive through the cable. If not, you would have to build your own connector, which is interesting and can help to learn a lot, but it´s not an easy thing. In a project I was working, we had to build several cables to adapt the signals to connect with the device, in my case an iPad1 and recently an iPad 4 although it works with the iPhone as well. As you know, or you should, you will have to learn about MFI.
You can find some information regarding that point here : Create an iPad app that can send/receive data via the USB cable?, but bear in mind everything goes through MFI, so it has its pros and cons....most of them cons. You can find several information here : https://developer.apple.com/programs/mfi/
good luck :)
I am pretty new to Linux so I apologize if I will ask some really simple stuff.
I am working on a custom board with SAM9G25 and Angstrom distribution as operating system.
The board as to act as a USB Device (Mass storage device), when will be connected to a Host computer. Right now I am simply enabling and removing the g_mass_storage module and the things are working fine.
In the final version, I need to manage the g_mass_storage module according to the connection and disconnection of a USB cable. I tought to use VBUS as an interrupt (also polling will be fine).
Here it comes my problem.
Since the VBUS GPIO is handled by the USB driver i cannot read it's status from userspace. I only see an interrupt count in /proc/interrupt.
I am asking if there is a way to get an interrupt (from the Driver) or to be able to read the VBUS GPIO value when the usb cable is connected/disconnected from the system.
I apreciate any kind of help.
I know this is a bit old, but I found the same problem, and found from userspace you can view the connection status from the udc sys class device. For example, on my architecture the status of USB can be viewed from:
/sys/class/udc/ci_hdrc.0/status
PC connection: configured
Power adapter: powered
Disconnected: not attached
I've read the AM335x architecture can be observed from:
/sys/class/udc/musb-hdrc.0.auto/current_speed
Best of luck
I have a peculiar question.
The case is that I have a TV that can use as source a USB flash drive for playing movies.
Do you think it would be possible to directly connect a PC and the TV USB to USB and using some software interface to determine the PC to act like a flash drive.
I think it can be done with a hardware driver, but I'm wondering if it can be done without that.
No, you can't, not even by writing a new driver.
A flash drive is a USB device, but your computer has only USB host ports. There's different circuitry needed in a device vs. a host (there are circuits that can do both, called USB on-the-go, but those are only found in peripherals).
Actually, you can - kind of.
http://www.eye.fi
This is a special adapter with a Wi-Fi adapter built in that allows you to connect to a computer (or the Internet).
Not quite what you asked but the effect is similar.