USB Host

Aviator168

Hi all,

Newbie here. Can anyone tell me which product can act as a USB host? I have project that needs to be connected to a USB device. Thanks.

Mike Green

Parallax's Memory Stick Datalogger acts as a USB host for mass storage devices and HIDs like keyboards, mice, and joysticks. It can also handle FTDI's USB to Serial Adapters and some printers (no built-in printer drivers ... just delivers characters).

Aviator168

Thank you very much for the quick reply. I though the Datalogger is just for collecting data and have them send to the PC at a later time.

Another question if you don't mind. I am implementing a sound device (1 microphone, mono-speaker, USB acting as host), the audio will be 8-bit 8000 samples/second. Is the processor fast enough to do this?

Mike Green

A Stamp isn't fast enough to handle the sound samples. Typical simple statement execution time is 140us or roughly 7000 per second.

A Propeller is more appropriate for your application and can easily handle the analog to digital conversion, digital to analog conversion and logging. If you're willing to use an SD memory card for the logging, the Propeller can also handle that directly.

Aviator168

I understand. However, I need send and receive the voice data via the USB interface. Can the Propeller be connected to a USB device?

Mike Green

A Propeller can act as a USB host under restrictive circumstances (low speed, HID only, maybe USB to Serial Adapter protocol). There's no general purpose USB host code that exists and experience suggests that the Propeller is too slow to handle things like the audio protocols without external hardware and there is no existing code or examples of this.

So, the Propeller is certainly capable of handling the audio, but not the audio USB connection. It's also capable of handling either an external USB datalogger or logging audio directly to an SD card in PC compatible format, but can't host a mass storage USB device directly.

Parallax has nothing that can handle USB audio.