user11007: Probably I'm asking a nonsense question but I'm new at interfaces.
I want to connect an USB barcode scanner to an Arduino (Uno or Mega). I've read that I need a USB host shield to achieve this. But I don't have any. I have a FTDI, so I suppose I could plug the USB output of the scanner into the FTDI and connect the FTDI to the UART port of Arduino. Then, I would be passing the USB output to Serial.
Is it correct? Thanks and sorry if I said something stupid!

user4143: No, that is completely wrong.
In USB you have hosts and devices. A device has to connect to a host. Your FT232 is a device. The barcode scanner is a device. Both of them need to be connected to a host for them to do anything.
So you need a USB host shield to act as that host.
However - check the manual for your barcode scanner: it may well have a RS-232 mode that it can be switched into (may need a different cable attached).

11007: <p>Probably I'm asking a nonsense question but I'm new at interfaces.</p>

<p>I want to connect an USB barcode scanner to an Arduino (Uno or Mega). I've read that I need a USB host shield to achieve this. But I don't have any. I have a FTDI, so I suppose I could plug the USB output of the scanner into the FTDI and connect the FTDI to the UART port of Arduino. Then, I would be passing the USB output to Serial.</p>

<p>Is it correct? Thanks and sorry if I said something stupid!</p>
 4143: <p>No, that is completely wrong.</p>

<p>In USB you have <em>hosts</em> and <em>devices</em>. A <em>device</em> has to connect to a <em>host</em>. Your FT232 is a <em>device</em>. The barcode scanner is a <em>device</em>. Both of them need to be connected to a <em>host</em> for them to do anything.</p>

<p>So you need a USB <em>host</em> shield to act as that host.</p>

<p>However - check the manual for your barcode scanner: it may well have a RS-232 mode that it can be switched into (may need a different cable attached).</p>
