Arduino USB Host or no USB Host?

• Arduino USB Host or no USB Host?
  Posted by zdelarosa00 on 21 May, 2015 22:59
• 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, 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
• #1 Reply
  Posted by ataradov on 21 May, 2015 23:10
• 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.
• #2 Reply
  Posted by zdelarosa00 on 22 May, 2015 03:48
• Quote from: ataradov on 21 May, 2015 23:10

  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?
• #3 Reply
  Posted by ataradov on 22 May, 2015 04:56
• 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.
• #4 Reply
  Posted by pickle9000 on 22 May, 2015 05:06
• Arduino Due only
  
  http://www.arduino.cc/en/Reference/USBHost
• #5 Reply
  Posted by timb on 22 May, 2015 12:02
• Arduino Mega ADK can do USB Host.
  
  
  Sent from my Tablet
• #6 Reply
  Posted by zdelarosa00 on 23 May, 2015 16:17
• 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 
• #7 Reply
  Posted by neslekkim on 23 May, 2015 16:39
• It's specified on the adafruit productpage, TTL Serial..
• #8 Reply
  Posted by zdelarosa00 on 24 May, 2015 16:53
• 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
• #9 Reply
  Posted by jeristair on 24 May, 2015 23:32
• Quote from: ataradov on 22 May, 2015 04:56

  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.