Attiny85 does not have the USB interface. It is made software from pine that can be only 1 or 0.

Question ?
Can I give up the voltage regulator from this scheme?

Attiny85 works to 5V. The USB the same.
But maybe it needs 3V3 for the USB high speed protocol.Or not ?

 

The 3.6 volt zener diodes clip the D+ and D- lines to a level acceptable for USB. I cannot see any use for the voltage regulator.

 

Wait a minute, is the Tiny85 playing the part of a host or an endpoint?

 

Wait a minute, is the Tiny85 playing the part of a host or an endpoint?

Attint85 is a device attached to the computer. Is a endpoint (peripheral device).

All I have to do is to test practice.

I have two options:
- I have Attiny45 (1.5$) which I program with PicKit2 (with averdud)
Search for the firmware if the code is free
- buy one digispark at 4$ and change it.

I know I can risk break the pieces. I will count this risk and assume it.

If I can make it play music from the USB stick, it will act as a host.
But when I schedule it, is peripheral device.

Actually, this arduino is an Attiny85 which is already programmed with a bootloader.

That boot program, knows the USB protocol, and write the program memory with what it receives on USB.

 

From:
http://codeandlife.com/2012/01/22/avr-attiny-usb-tutorial-part-1/
"While USB power is 5V, the data lines require 3.3. Some computers tolerate 5V logic but not all. To play by the book, you have three options:

1. Limit the voltage provided by USB to 3.3V
2. Power the circuit externally from 3.3V
3. Use resistors, diodes or zener diodes to convert 5V logic to 3.3V"
4. (What you said)

 

The 5 volt regulator would be necessary when the controller plays host.

 

I like this circuit due to the price. FT232 or similar are more expensive than this microcontroller.

 

Does the digispark board not come with functional USB? Seems kind of a fraud if it doesn't.

FWIW, the regulator is for external power.

 

Below is something similar it is the USBASAP programmer. Only $1.52 postage paid win an ATMEGA8 @ 12 MHz (About the same as the bare ATMEGA8 from Digikey would cost, less shipping). It works with AVRDude and can be reprogrammed to imitate the AVRISP MKII to run under AVRStudio 4.X. Or, you ca use it as a USBASAP peripheral. I think the hardware is compatible with VUSB.




http://www.ebay.com/itm/USB-ISP-USB...694845?hash=item46402236fd:g:L6sAAOSwuMFUjQCX