General discussions about V-USB, our firmware-only implementation of a low speed USB device on Atmel's AVR microcontrollers
			
		
		
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																			 geckosenator1
						
						
													
							
						
									
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								by geckosenator1 » Fri Feb 20, 2009 3:27 am
			
			
			
			
			Hello.
I would like the ability to consume less power when not communicating via usb.
There are 2 ways, sleeping, or reducing the oscillator.  Which one can do safely and be able to switch back if usb traffic resumes?
I found in the Readme:
Code: Select all
Implementing suspend mode AVR-USB does not implement suspend mode. This means that the device does not reduce power consumption when the host goes into sleep mode. Device firmware is free to implement suspend mode, though. See USB2LPT for an example. 
I could not find the USB2LPT example, does anyone know of it?
 
		 
				
		
		 
	 
	
				
		
		
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																			 horo
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								by horo » Fri Feb 20, 2009 10:44 am
			
			
			
			
			
			
			
									
									
						 
		 
				
		
		 
	 
	
				
		
		
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																			 christian
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								by christian » Sat Apr 11, 2009 7:14 pm
			
			
			
			
			These are two different issues. USB2LPT is about drawing less power when the host is in sleep mode. What you want to do is consume less (battery?) power if not connected to USB or if there is no USB traffic. It should be safe to put the AVR into sleep mode as long as the hardware interrupt can wake it.