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dhouston
- 18th September 2011, 16:43
This may be in the wrong place so feel free to move it, if so.

I'm researching using a small PIC (12F1822) with a MAX3421E as a Serial<->USB_Host adapter for a specific device. Is this feasible? ...using internal oscillator?
mister_e
- 18th September 2011, 16:56
Yes you can, it's a SPI device, no problem using the internal OSC.

You may also check Microchip's MCP2200 (http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en546923) which is a USART type.
dhouston
- 18th September 2011, 17:47
Thanks Steve - the MCP2200 looks even better as I want to also design an Arduino shield that serves as a USB host and my Zarduino (http://davehouston.org/Arduino.htm)TM boards are all 3.3V or 5V. It's also a better price. And the RS232 eval board may solve an immediate problem for someone else looking for a way to interface a USB peripheral to an existing embedded device that has multiple RS232 ports.

I had posted a similar query on Jan Axelson's Ports Forum (http://www.lvr.com/forum/index.php) asking if there was a similar 3.3V-5V chip but now I have the answer.
mister_e
- 18th September 2011, 18:04
For really small and simple USB stuff, you could even skip the PIC thing.

It is also really easy to configure, you can even develop your own PC software around their DLL. There's one DLL for managed and one for unmanaged code. Really interestng.
dhouston
- 18th September 2011, 18:07
After looking at the datasheet, the MCP2200 appears to be Serial<->USB_Peripheral only. I need to play embedded host to a peripheral.

I would still like to find a chip like the MAX3421E with SPI but able to operate from 3.3-5V.

Microchip's USB-enabled PICs can play host but that's overkill for my need.
HenrikOlsson
- 18th September 2011, 18:14
Hi,
Correct me if I'm wrong but aren't those two chips (MCP2200 and MAX3421E) two different things?
The MCP2200 seems to be like the ever so popular FTDI232, ie it acts as a USB device. The MAX3421 however seems to be a USB host to which you connect a device, like a thumb drive or whatever. Actually it seems like the MAX3421 can act as either device or a host.

/Henrik.

EDIT: Ah, OK you noticed that while I was typing....