I have asked the Google but found no answer about this.... 
Can ATTiny85 connect to the computer via USB? And then do serial communication? With the Firmata?
If ATTiny85 can't do that, can you recommend me another small and cheap IC?
I need at least 3 PWM output and can do serial communication 
Thanks
That's a great question. I've not seen it anywhere either - there was this thread in the DigiStump forum which mentioned it. Digispark is ATTiny85 based. It sounds promising, but was still only theoretical rather than saying it had been done.
Cheers ! Geoff
strykeroz:
That's a great question. I've not seen it anywhere either - there was this thread in the DigiStump forum which mentioned it. Digispark is ATTiny85 based. It sounds promising, but was still only theoretical rather than saying it had been done.Cheers ! Geoff
oh yeah thanks, I already seen it before. 
But I don't have enough money on Paypal to buy it 
And I'm afraid that I cannot find it on my town
So I want to make it myself 
If there is any simplier than Digispark's schematic?
Thanks!
I only mentioned Digispark since it was based on the uC you mentioned specifically. There's no confirmation Firmata has been ported to run on that platform yet, at least that I could find.
You could start with an Arduino Pro Mini or similar for a very low cost, not much more than a standalone microcontroller.but gives you a complete and working Arduino for under $USD5 delivered, plenty around that price point on eBay based on ATMega328. You'll still need a USB converter (FTDI breakout say) to talk to your PC. They're about that same price - so around $USD10 all up.
At least you know Firmata will work on Arduino via the library.
Cheers! Geoff
Smankusors:
If ATTiny85 can't do that, can you recommend me another small and cheap IC?
I need at least 3 PWM output and can do serial communication
Solder the pins to it and it works just like an "IC". You can stick it in a breadboard, chip socket, etc.
Personally, I would go with an Atmega328P-PU uC for the added I/O & 4x SRAM.
On the Attiny85, Trinket (Adafruit only supports 2 PWM). A trinket can be converted to a Digispark which supports 3 PWM (verified) and a better boot loader, IMO.
http://www.hackster.io/rayburne/trinket-firmware-exorcism
The Digispark and Trinket can both handle send-only serial comm via their libraries. SoftwareSerial leaves no room for user programs.
If you want to control the Arduino from the PC, for the Atmega328 you may want to look into iArduino...
http://n.mtng.org/ele/arduino/iarduino.html
This works well and the GUI is easy to use. Obviously, not as flexible as Firmata.
strykeroz:
I only mentioned Digispark since it was based on the uC you mentioned specifically. There's no confirmation Firmata has been ported to run on that platform yet, at least that I could find.You could start with an Arduino Pro Mini or similar for a very low cost, not much more than a standalone microcontroller.but gives you a complete and working Arduino for under $USD5 delivered, plenty around that price point on eBay based on ATMega328. You'll still need a USB converter (FTDI breakout say) to talk to your PC. They're about that same price - so around $USD10 all up.
At least you know Firmata will work on Arduino via the library.
Cheers! Geoff
fungus:
arduino pro mini for sale | eBaySolder the pins to it and it works just like an "IC". You can stick it in a breadboard, chip socket, etc.
I think Arduino Pro Mini has too much pins that I don't need 
I already created this project on my Arduino Uno and I want to make this project permanent.
The project : http://www.youtube.com/watch?v=TPKzy2THaHc
mrburnette:
Personally, I would go with an Atmega328P-PU uC for the added I/O & 4x SRAM.
well..... That IC is too big for this project
Trinket can do 3 PWM (two using analogWrite, one more using a couple of tiny (no pun intended) routines on the learn.adafruit.com site under analog meter clock).
Softwareserial does not bloat the code too much - I have had many Trinket projects fit the functionality plus softwareserial (or Nick's SendOnlySoftwareSerial) in the available code space.
TheKitty:
Trinket can do 3 PWM (two using analogWrite, one more using a couple of tiny (no pun intended) routines on the learn.adafruit.com site under analog meter clock).Softwareserial does not bloat the code too much - I have had many Trinket projects fit the functionality plus softwareserial (or Nick's SendOnlySoftwareSerial) in the available code space.
Oh thanks, Trinket looks cheaper than Digispark
But when I tried to buy it online..... Trinket costs more than $50 than Digispark!
Digispark costs $13 while Trinket costs $57
I will try to look at my country local store 
Any other suggestions?
Any other suggestions?
Build your own clone, use Trinket or Digispark boot loader and libs...
http://www.hackster.io/rayburne/chachka-trinket-attiny85-clone
Ray
Or go back to the Arduino Pro Mini. It's the same width and 3mm longer than Digispark (comparing them side by side on my desk here with a ruler) and has a full ATmega328P. Its' self-contained with power regulation, requires no assembly aside from headers if you want those, and it's cheap.
Easy as. Geoff
Or go back to the Arduino Pro Mini.
Yes!
Similar to my #5, a most appropriate solution.
I have maybe 35 virgin tiny85 in tubes and 3 or 4 on the antistatic workbench and I mainly use these as co-processors in larger projects (usually IR receivers.)
http://www.hackster.io/rayburne/infrared-dedicated-decoder
But, they are also fun little uC for rainy day projects or blinky toys. At about 85¢ each, they are inexpensive enough to use in dead-bug designs.
However,
The atmega328P boards give 4x the SRAM and full sketch compatibility with UNO and represent the most compatible and least expensive option for general project use.
Ray
Oh wait, I'm want to control the laptop fans too, so I need at least 5 PWMs
Look like Arduino Pro Mini is my choice, thank you guys!
Wait, is Arduino Pro Mini cheaper than Arduino Mini?