Objective Development Forums

Re: AVR-USB + ATTiny24 = Arduino USB interface?

2008-09-12T22:33:14+02:00

henni wrote:> Can I use a ATTiny(24) to work as USB interface for a Arduino?
Please specify what an Arduino should be (e.g. by typing a web address).

Google is your friend..

Statistics: Posted by Grendel — Fri Sep 12, 2008 10:33 pm

Re: AVR-USB + ATTiny24 = Arduino USB interface?

2008-09-12T09:58:41+02:00

> Can I use a ATTiny(24) to work as USB interface for a Arduino?
Please specify what an Arduino should be (e.g. by typing a web address).

>...i.e. the output of the ATTiny is connected to the input of the ATMega?
So I guess it's a somehow ATmega based PCB with some interface.
What is the interface? Should software compatibility be a concern?

> Can I modify the ATTiny code so that if gets some input it set a pin out low so it can be used as a signal to reset the ATMega?
Yes, you have to program the ATtiny with the program you need.
But, BTW, why someone needs combinatorical logic to reset a µC?

>... My idea would be to make a Arduino-like board that does not uses the FT232 which needs SMT soldering but is all DIP based.
Ah, looks like you want a UART interface.
I cannot understand why people reject using SMD ... FT232 is really a good solution for you. I hope you know that you don't need level converter (MAX232 and similar), otherwise, buy any cheap USB-serial converter (Reichelt: about 5 €; it's not worth to clone its functionality).

Maybe you decide to use an ATtiny45 and AVR-CDC as starting point, that saves the need for a crystal and saves space.
See http://www.recursion.jp/avrcdc/
You can control the ATmega !RESET pin by special serial data or by controlling modem status, like SETDTR or SETBREAK.

Same for all ATtinys: They have no UART interface! Serial communication must be done by toggling bits, and you cannot achive more than about 4800 baud because interrupts are lengthly disabled by USB software. If you need more speed, the solution is an ATmega.

Statistics: Posted by henni — Fri Sep 12, 2008 9:58 am

AVR-USB + ATTiny24 = Arduino USB interface?

2008-09-11T05:41:45+02:00

Hi,

I looked at many posts but I'm still unclear on a few things.
Can I use a ATTiny(24) to work as USB interface for a Arduino?
i.e. the output of the ATTiny is connected to the input of the ATMega?

Can I modify the ATTiny code so that if gets some input it set a pin out low so it can be used as a signal to reset the ATMega?

Is this feasible or not? My idea would be to make a Arduino-like board that does not uses the FT232 which needs SMT soldering but is all DIP based.

Thanks a lot

michelef

Statistics: Posted by michelef — Thu Sep 11, 2008 5:41 am