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Electronics => Microcontrollers => Topic started by: zdelarosa00 on May 21, 2015, 10:59:31 pm

Title: Arduino USB Host or no USB Host?
Post by: zdelarosa00 on May 21, 2015, 10:59:31 pm
Hi everyone, my third question on the forum here, now is... I know Arduino has a usb controller chip on it to conenct it to the compter and to use the IDE and program it, now my question is.. Can I plug a USB device to an Arduino without a USB-Host shield?, I've seen cases like this video: https://www.youtube.com/watch?v=1diFaa5OsFg, (https://www.youtube.com/watch?v=1diFaa5OsFg,) where you just use the USB pair of pins on the device and TX & RX on he Arduino to make the couple work, recieve and send information, but I've asked(?) before and apparently even with a simple usb mouse or small keyboard you need a USB host device or a "USB-UART / USB-RS232" (or are the shields actually the same rs232?) translator thing in order to make the couple work as the arduino being the host and the usb device to be used. Am I completely lost here..?. Anyway, thank you and I appreciate any help, good vibrations to everyone from Mexico.  :-+

USB Host Shield: http://www.dx.com/p/usb-host-shield-2-0-board-166217#.VV5jMai3vKg (http://www.dx.com/p/usb-host-shield-2-0-board-166217#.VV5jMai3vKg)
Title: Re: Arduino USB Host or no USB Host?
Post by: ataradov on May 21, 2015, 11:10:09 pm
No,  standard Arduino can't do host on its own. What makes you think that it is a USB host on that video? They are connecting a sensor with I2C/SPI/UART/whatever interface and use Arduino USB port for serial communication.

Arduino Zero has USB Host controller, but it is mostly vaporware right now.
Title: Re: Arduino USB Host or no USB Host?
Post by: zdelarosa00 on May 22, 2015, 03:48:25 am
Quote from: ataradov on May 21, 2015, 11:10:09 pm
They are connecting a sensor with I2C/SPI/UART/whatever interface and use Arduino USB port for serial communication.

So if I connect a keyboard or mouse to TX &  RX should I get results on the serial monitor?
Title: Re: Arduino USB Host or no USB Host?
Post by: ataradov on May 22, 2015, 04:56:47 am
No, you won't. There is no RX and TX in USB. You can connect PS/2 keyboard, but that's probably not what you want.

Also, you don't just get results on the serial port, you need to write firmware to do so.
Title: Re: Arduino USB Host or no USB Host?
Post by: pickle9000 on May 22, 2015, 05:06:01 am
Arduino Due only

http://www.arduino.cc/en/Reference/USBHost (http://www.arduino.cc/en/Reference/USBHost)
Title: Re: Arduino USB Host or no USB Host?
Post by: timb on May 22, 2015, 12:02:10 pm
Arduino Mega ADK can do USB Host.


Sent from my Tablet
Title: Re: Arduino USB Host or no USB Host?
Post by: zdelarosa00 on May 23, 2015, 04:17:48 pm
And can I program an Uno to work as a USB to Serial converter?, or as a USB Host? .... And that means that device in the video is not USB??, it looks like it is and all the similar fingerprint readers that i've seen are USB  :(
Title: Re: Arduino USB Host or no USB Host?
Post by: neslekkim on May 23, 2015, 04:39:13 pm
It's specified on the adafruit productpage, TTL Serial..
Title: Re: Arduino USB Host or no USB Host?
Post by: zdelarosa00 on May 24, 2015, 04:53:08 pm
Its true, I was planning to use this one : http://www.dx.com/es/p/mini-usb-2-0-biometric-fingerprint-reader-password-security-lock-for-pc-122346#.VWIBxKgwLT9 (http://www.dx.com/es/p/mini-usb-2-0-biometric-fingerprint-reader-password-security-lock-for-pc-122346#.VWIBxKgwLT9)
Title: Re: Arduino USB Host or no USB Host?
Post by: jeristair on May 24, 2015, 11:32:50 pm
Quote from: ataradov on May 22, 2015, 04:56:47 am
No, you won't. There is no RX and TX in USB. You can connect PS/2 keyboard, but that's probably not what you want.

Also, you don't just get results on the serial port, you need to write firmware to do so.

If you're talking about a USB Keyboard here, then yes, it would work, most wired USB Keyboard's can default back to the PS/2 interface using the USB connector.