Hello,
i would need to source a TTL-grade (5V) digital array from USB port (or Serial 0 and 1 pins) , and i can use a Arduino Uno device only.
If anyone has any ideas can help me?
thank you in advance!
Your question is too vague. Provide more details.
Need just a little more description of what you want to do...
Arduino, driven by 5V will produce TTL compatible outputs.
I apologize for being unclear,
to say it in another way, I would need 8 more digital i/o pins, so i was thinking about getting them from the Atmega328 serial output directly or through USB...
there is some easy way to do this?
Usual way mentioned is to add a port expander, connected via I2C pins.
You can add shift-in and shift-out registers, controlled via SPI for faster intefacing.
Or go up a size in microcontroller. Atmega1284P has 32 IO (vs the Atmega328P with 20).
I offer a board that brings them all out, available as a kit, or assembled, purchasable via paypal.
http://www.crossroadsfencing.com/BobuinoRev17/
OK!
thank you Robert, this time i cannot modify pre-installed Arduino hardware, only i can remotely add connectors and so on,
but i like Bobuino!
regards
Ok; add some shift registers.
adding a shift register requires (at least) 3 digital pins, i2c is best way for me.
thank you again!