Intro: Auto Reset of a USB Device.
Don't we all hate having to unplug then re-plug a usb device if it has stopped responding? My USB UIRT is the key to my home access and comfort automation. Occasionally it locks up and I must either re-plug it or reboot the pc.
Here is how I fixed this madness using my existing Labjack U3/flowstone based home automation system.
You can of course use a programmable timer relay to cycle power for a few seconds each day if you don't have a home automation system like I do.
Step 1: Putting a New 5Volt Power Lead.
Basically I removed the 5Volt power lead from the UIRT circuit board and substituted a separate wire for 5Volt power. The new power lead will have its power cycled OFF via a normally closed relay contact.
I have a 5Volt supply from my desktop pc atx psu which will be the new power feed into the USB UIRT.
Step 2: Hardware and Software to Make the Power Cycle.
I already have a relay card dedicated to cycling power to my internet modem, infrared relays and wifi router. I simply used another relay just for 5V switching. These relays inputs are connected to a Labjack U3 digital out channel.
The software I developed in Flowstone provides automatic and manual switching to cycling power i.e. turn on and off the relays.
Step 3: Completion!
After having the new 5Volt power lead connected to the 5Volt relay NC contact, I secured the USB UIRT in its new location and now my home automation system for home access and comfort has auto healing capabilities!