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USB Host?

N

Nick

Jan 1, 1970
0
I need to write data to a USB device (a printer) from a MCU. I believe I
need a USB host controller to do this, so USB-enabled PICs etc. won't be
suitable.

This is purely a one-on-one configuration, there will be no other USB
devices or hubs connected, and the make/model of printer will be
predetermined.

What might be the easiest way to achieve this? It's for a commercial
application, though production qty will be low (100s).

Thanks,
Nick
 
L

larwe

Jan 1, 1970
0
Nick said:
I need to write data to a USB device (a printer) from a MCU. I believe I

What might be the easiest way to achieve this? It's for a commercial

Depends on the scale of the application. If it already requires a
32-bit MCU then you could go with a PPC or ARM part that has USB host
on-chip.

If you're trying to do it "writ small", look at USB and USB-On-The-Go
controllers from Cypress, Atmel et al.
 
N

Nick

Jan 1, 1970
0
Depends on the scale of the application. If it already requires a
32-bit MCU then you could go with a PPC or ARM part that has USB host
on-chip.

If you're trying to do it "writ small", look at USB and USB-On-The-Go
controllers from Cypress, Atmel et al.

Thanks. This is indeed a small app from the MCU's perspective (8-bit is
fine).
 
M

Mike Harrison

Jan 1, 1970
0
I need to write data to a USB device (a printer) from a MCU. I believe I
need a USB host controller to do this, so USB-enabled PICs etc. won't be
suitable.

This is purely a one-on-one configuration, there will be no other USB
devices or hubs connected, and the make/model of printer will be
predetermined.

What might be the easiest way to achieve this? It's for a commercial
application, though production qty will be low (100s).

Thanks,
Nick


Take a look at this product :
http://www.ghielectronics.com/USBhost.htm

For low volumes it's probably the only viable solution as there is a lot of software involved in
doing USB host.

Also look at USB On-The-Go (OTG) stuff, e.g. from Philips.
 
N

Noone

Jan 1, 1970
0
Nick said:
I need to write data to a USB device (a printer) from a MCU. I believe I
need a USB host controller to do this, so USB-enabled PICs etc. won't be
suitable.

This is purely a one-on-one configuration, there will be no other USB
devices or hubs connected, and the make/model of printer will be
predetermined.

What might be the easiest way to achieve this? It's for a commercial
application, though production qty will be low (100s).

Thanks,
Nick

Nick;

This is not so difficult as it might appear. Since you are supporting only one device, it is relatively easy. You will need to get a USB analyzer (borrow, rent, buy) and simply log the data exchange between the device an a PC. You will need to capture the enumeration sequences and the data transfer sequences.

Attach a USB host chip (like the Cypress HS811) to your uC and then program the chip to elicit the same data exchanges as observed on the PC. The learning curve will be mostly getting familiar with the USB Host chip structure, configuration and usage.

We have done this with a number of devices.

Blakely
 
N

Noway2

Jan 1, 1970
0
I have used the Philips isp1161A1, OTG controller. It has a few quirks
but it does work. I would also suggest that you try to find a
reference schematic implementation as this will show you some of the
finer details of implementing a design that works, ie where to put the
various filter capacitors, etc. I would also recommend that you find a
specification on PCB layout for the USB host controller. I believe
that Intel has published one for geared towards high speed USB, which
is backwardly compatible with full speed devices like the 1161.
 
J

John Jardine.

Jan 1, 1970
0
Nick said:
I need to write data to a USB device (a printer) from a MCU. I believe I
need a USB host controller to do this, so USB-enabled PICs etc. won't be
suitable.

This is purely a one-on-one configuration, there will be no other USB
devices or hubs connected, and the make/model of printer will be
predetermined.

What might be the easiest way to achieve this? It's for a commercial
application, though production qty will be low (100s).

Thanks,
Nick
Don't know if this is relevant to your particular printer but standard USB
printers generally assume that their supplied PC driver software will be
doing all the bit image graphic calculations for driving the print head and
platten etc. The printer companies will not supply this info (I've tried).

[Rant mode ON ... For non PC use, USB is a f****** grade #1, software
abortion.
And thinking about it for a mS ... even for PC use.
There, I feel better now :)
 
H

Hans-Bernhard Broeker

Jan 1, 1970
0
In comp.arch.embedded John Jardine. said:
Don't know if this is relevant to your particular printer but
standard USB printers generally assume that their supplied PC driver
software will be doing all the bit image graphic calculations for
driving the print head and platten etc.

This would be relevant, if it weren't so blatantly wrong.

The majority of consumer printers being too dumb to do their own
rendering exhibits a random temporal coincidence with them having USB
ports, at best. So-called "GDI printers", a.k.a. "Windows printers"
have existed longer than USB has been the de-facto only printer port.

The sanity of a printer's control protocol has next to nothing to do
with its communication technology, with only one major exception: real
honest-to-god network printers still tend to have usable programming
languages, like PostScript.
 
M

Michael N. Moran

Jan 1, 1970
0
I like the section in their docs on USB Mythology!

Huh? Maybe I'm just tuned to the wrong frequency, but how does
that section qualify as describing mythology?


--
Michael N. Moran (h) 770 516 7918
5009 Old Field Ct. (c) 678 521 5460
Kennesaw, GA, USA 30144 http://mnmoran.org

"So often times it happens, that we live our lives in chains
and we never even know we have the key."
The Eagles, "Already Gone"

The Beatles were wrong: 1 & 1 & 1 is 1
 
R

Rich Grise

Jan 1, 1970
0
Huh? Maybe I'm just tuned to the wrong frequency, but how does that
section qualify as describing mythology?

I was wondering the same thing. Maybe dan.ellis likes it because it
gives a fairly comprehensible explanation of the USB Black Magick. ;-)

Cheers!
Rich
 
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