Pages: [1]   Go Down
Author Topic: USB reset problem?  (Read 741 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
God Member
*****
Karma: 21
Posts: 650
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

I've got a Win XP laptop that causes a reset to occur on a USB connected Arduino Nano whenever I connect/disconnect another USB device from the other USB port (this thinkpad laptop only has two USB ports). 

I found this surprising for two reasons: a) I would have thought that the connection/disconnection of a USB device to a USB port would have/should have any affect on a device already connected on another port, and b) I'm surprised I haven't noticed this phenomenon before this!

Any experts in the nitty gritty of USB out there care to offer an opinion as to whether this behaviour is expected/explicable?

This reset on the Nano occurs whther or not it also externally powered (at first I thought there might just be a transient power supply glitch on the USB connection causing the reset.)

I thought I'd post this as a sanity check before embarking on any serious investigation and debugging, in case this is actually "normal" behaviour. 

Logged

WiFi shields/Yun too expensive? Embeddedcoolness.com is now selling the RFXduino nRF24L01+ <-> TCP/IP Linux gateway: Simpler, more affordable, and even more powerful wireless Internet connectivity for *all* your Arduino projects! (nRF24L01+ shield and dev board kits available too.)

Global Moderator
Dallas
Offline Offline
Shannon Member
*****
Karma: 176
Posts: 12286
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset


Try this... With Serial Monitor connected to the Nano, connect and disconnect the other device.  Does the reset still occur?
Logged

Offline Offline
God Member
*****
Karma: 21
Posts: 650
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset


Try this... With Serial Monitor connected to the Nano, connect and disconnect the other device.  Does the reset still occur?

No!

But if I don't have the serial montor open, it _is_ consistently resetting...

What's going on? (Enquiring minds need to know...)
« Last Edit: November 15, 2012, 02:46:25 am by pico » Logged

WiFi shields/Yun too expensive? Embeddedcoolness.com is now selling the RFXduino nRF24L01+ <-> TCP/IP Linux gateway: Simpler, more affordable, and even more powerful wireless Internet connectivity for *all* your Arduino projects! (nRF24L01+ shield and dev board kits available too.)

Global Moderator
Dallas
Offline Offline
Shannon Member
*****
Karma: 176
Posts: 12286
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset


There is an application that is probing serial ports (or USB devices) when a device change notification is sent by the operating system.  The usual culprit is a PDA / mobile phone application.

As far as I know nothing in the Windows XP operating system behaves that way.
Logged

Offline Offline
God Member
*****
Karma: 21
Posts: 650
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset


There is an application that is probing serial ports (or USB devices) when a device change notification is sent by the operating system.  The usual culprit is a PDA / mobile phone application.

As far as I know nothing in the Windows XP operating system behaves that way.


Well OK then! I'm so glad I asked here before wasting too much time trying to figure this out. (I somehow doubt I would have, actually... figured it out, that is.)

Thank you kindly for your wisdom and assistance, sir. smiley
Logged

WiFi shields/Yun too expensive? Embeddedcoolness.com is now selling the RFXduino nRF24L01+ <-> TCP/IP Linux gateway: Simpler, more affordable, and even more powerful wireless Internet connectivity for *all* your Arduino projects! (nRF24L01+ shield and dev board kits available too.)

Offline Offline
God Member
*****
Karma: 21
Posts: 650
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Never did get to the bottom of this. But another possible culprit is the behavior of the RXTXcomm.jar serial driver for Java used by the Arduino IDE. This link describes is an interaction with another USB device causing similar symptoms:

http://dangerousprototypes.com/forum/viewtopic.php?t=574
Logged

WiFi shields/Yun too expensive? Embeddedcoolness.com is now selling the RFXduino nRF24L01+ <-> TCP/IP Linux gateway: Simpler, more affordable, and even more powerful wireless Internet connectivity for *all* your Arduino projects! (nRF24L01+ shield and dev board kits available too.)

Global Moderator
Dallas
Offline Offline
Shannon Member
*****
Karma: 176
Posts: 12286
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

But another possible culprit is the behavior of the RXTXcomm.jar serial driver for Java used by the Arduino IDE.

I disagree.  The evidence presented on that page indicates "SUMP Java Client" is the culprit.  In that situation, RXTXcomm.jar is just the route to the serial port.
Logged

Pages: [1]   Go Up
Jump to: