table in the DSx 1-Wire network cables data sheet. Both adapters are based on the DS USB-to-. 1-Wire bridge chip. Free software drivers for. Both adapters are based on the DS USB-to-. 1-Wire bridge chip. See the DS data sheet for the conditions where SUSO is active. Revision C of the. DS Usb to 1-Wire Bridge Chip. FEATURES. Communicates at regular and overdrive 1Wire® speeds Supports 12V EPROM programming and stiff 5V.
|Published (Last):||6 July 2004|
|PDF File Size:||12.91 Mb|
|ePub File Size:||2.3 Mb|
|Price:||Free* [*Free Regsitration Required]|
Search everywhere only in this topic. Usb problem with DS I’m doing my first experiments with owfs and a few one-wire devices. I made a simple interface with the DS USB-to-one-wire-bridge according to the application notes from dallas. I was impressed that everything seems to work very fine at first. It happens obviously while accessing the one-wire bus: Invalid argument dmesg looks like this: USB disconnect, address 4 usb USB disconnect, address 5 usb Only uhci is loaded since there is no 2.
If i dis- and reconnect the DS without reloading the module the following happens: USB disconnect, address 3 usb Kernel is a plain 2. Yesterday i’ve discovered that the problem disappears, if i connect the ds via my usb-hub to the notebook. This sounds first more like a hardware problem to me. Probably the usb port of the hub is less picky with some electrical parameters than the notebook itself? But in the meantime i’ve testet the two built ds interfaces on several other machines and they worked flawlessly there.
And i would say that the ifs are electrically well designed. Additionally every other peripheral like webcams, cardreader, hdd work on the omnibook with or without the hub. This is all very strange to me and i’m a bit helpless where to search the error. The DS surrounding hardware? Thank you in advance and sorry for my bad english! Klaus This SF.
ds datasheet & applicatoin notes – Datasheet Archive
Click to get it now. Sven — “Thinking of using NT for your critical apps?
Isn’t there enough suffering in the world? In reply to this post by Sven Geggus. On Mon, 4 Jun Hm, as written even this passive hub hub without own power supply helps. But i would prefer to do it without the hub. Particularly i would like to have an explanation for this behaviour. In the meantime i’ve tried to increase the capacitors in the 5V Power supply line and after the 3,3V Regulator which might be indeed a little bit small.
But this makes no improvement which would surprised me. There must be something else wrong In reply to this post by Jan Kandziora. Monday, June 04, 9: Does that mean it’s a known issue?
But i can’t imagine that this usb-port which is capable of mA should have a problem with a few mA. Spikes and something like that on the power lines should be sufficiently blocked by Capacitors and RF-Chokes which i already placed there.
DS Datasheet(PDF) – Maxim Integrated Products
And due to your recommends i increased the Capacitors now. Since this is your circuit, it would be hard to have prior reports. OWFS certainly doesn’t know or care about hubs — it just uses libusb to enumerate USB devices and libusb for all communication. I realize your circuit only uses a few mA, but perhaps you are supplying a larger current to the 1-wire bus which you are powering datashet you realize?
Any review, retransmission, dissemination or other use of or taking dztasheet any action in reliance upon this information by persons or entities other than the intended recipient is prohibited.
If you received this information in error, please contact the Compliance HelpLine at and properly dispose of this information. Thought you are talking about somebody else: Yes that’s how i expected. And of course the error is not caused by owfs itself. Althought the bus is planed with a length of about 50 meters and devices there is only one 18S20P for testing at the moment.
I have a mA Fuse in the 5V supply line of the usb bus. In the meantime i compiled debuging support in the usb kernel modules. Now the failure looks like this: Best wishes, Klaus This SF. In reply to this post by Vortex Empty capacitors are like short circuits. You have to limit the current flowing into empty capacitors by applying a resistor or better a choke coil to the supply lines.
There are fuse deratings to dz2490 the neccessary current ratasheet a given time. This is why melting fuses datasheeh useless as soon as high-speed datahseet switches should be protected. Your fuse protects the onewire cable, not the interface circuit.
(PDF) DS2490 Datasheet download
Your laptop however, may use such a switch — because a molt fuse is inconvenient in a laptop — and thus, cause problems. But i think the usb power supply isn’t switched on or off. So the Capacitors have to be loaded only if i plug in the device.
And that’s not the problem.
The failure happens after a few successful transactions. If the power supply would be switched the choke coils would make bad things too. At least if they are large enough to store reasonable amounts of energy.
At least there would be large voltage peaks then Of course the peripheral device may be in some sort oft sleep mode until it’s initialized by a driver. But the power supply on the usb-bus is on all the time. At least in my experiences. The facts about burning the fuse are certainly right.
But this current peaks should be blocked by the capacitors in the usb power supply lines 33pF, nF, 4,7uF. If this is not sufficient i guess i would need a choke coil instead which is larger than the whole circuit itself: But i will test your advice.
Hm, at the weekend i will have access to some testing equipment and then i will check this. As soon the host controller detects the device speed resistor — the 1. In case a device has a failure, the usb driver can turn off the power for the specific port.
Usb problem with DS2490
It may do so if the device is to be powered off due to power saving issues. The power is switched off if the presence resistor is there but the device does not respond to the initiation handshake, too. It may be a related issue, though.
The reason may be that absurd USB “devices” like this http: If they are empty, they cause additional current flow. That’s why you need an LC or RC circuit, not a capacitor alone.
You could use an If you want to try with a series resistor: A 6 Ohms resistor will limit the current at 5V short circuit to about mA. That may be low enough not to trigger any overcurrent circuit in the host adapter. Because it will too lower the supply voltage about 0. If your circuit draws lower current, you may increase the resistor, though.
Anything that can go wr fortune: Segmentation violation — Core dumped This SF. I investigated the setup again at last weekend. Somebody on linux-usb Mailinglist explaind the “failed with status ” message. I’ve discovered that there is a complete impedance missmatch between the ds and the usb-port of this laptop. But on the Notebook side there are at least pf expected.
Wouldn’t this be a chicken and egg problem? It’s done in the same manner with the ds Kind regards, Klaus This SF. What does the USB standard say on that?