Which Handheld would you recommend

[GMM50]

Hello:

I'm looking to control an embedded computer with a Handheld type
device via an USB link.
The embedded system is our design and will act as a Host device.

The Handheld device requirements are:
Run JAVA
Good development environment
Graphic touch screen
Low cost.

I know about Palm. Does anyone have comments or recommendations on
specific models.

Thanks
George

 

[Roedy Green]

I'm looking to control an embedded computer with a Handheld type
device via an USB link.
The embedded system is our design and will act as a Host device.

I don't have personal experience, but check out the Blackberry.

http://na.blackberry.com/eng/developers/downloads/jde.jsp

These things seem to have become synonymous with wireless handhelds.

Your apps would have a nice fat potential market.

If you are just interested in experimenting or developing, you don't
actually need a hand held device. There are various JME simulators for
the desktop.

see http://mindprod.com/bgloss/blackberry.html

The Blackberry site is very light on technical details and Java
details. I have written the webmaster twice asking him to fix it.

 

[Martin Gregorie]

I don't have personal experience, but check out the Blackberry.

http://na.blackberry.com/eng/developers/downloads/jde.jsp

These things seem to have become synonymous with wireless handhelds.

Your apps would have a nice fat potential market.

If you are just interested in experimenting or developing, you don't
actually need a hand held device. There are various JME simulators for
the desktop.

see http://mindprod.com/bgloss/blackberry.html

The Blackberry site is very light on technical details and Java
details. I have written the webmaster twice asking him to fix it.
>

You could also look at iPAQs. Even the older ones have USB support,
there is quite a lot of documentation available and there are lots of
used ones on eBay.

Are you aware that USB is not a symmetric protocol? USB devices have a
master/slave relationship hard wired into them, so a slave can't act as
a master. PDAs are always slaves, so your embedded device must be a
master.

If USB isn't already set in stone it might be worth looking at other
peer to peer interfaces, such as RS-232 or Ethernet because of this.
Most are quite easy to use e.g. Lantronics sell an RJ-45 Ethernet socket
that you can connect directly to the serial pins on a microprocessor and
you can get Ethernet adapters for iPAQ PDAs.

 

[Pavel Lepin]

You could also look at iPAQs. Even the older ones have USB
support, there is quite a lot of documentation available
and there are lots of used ones on eBay.

Are you aware that USB is not a symmetric protocol? USB
devices have a master/slave relationship hard wired into
them, so a slave can't act as a master. PDAs are always
slaves, so your embedded device must be a master.

I believe WM-based HTC Advantage X7500 and X7501 have an USB
host on board. Those are somewhat larger and heftier than
your typical PDA, though. Also it should be noted that, in
my experience, vendor-supplied JVMs on WM-based devices are
mostly MIDP-only: don't know for certain, but I think that
would cause problems trying to work with said USB host.

Anyway, I'm not sure how relevant all of this is to the OP
since he explicitly specified that his embedded device is
going to act as a host.

 

[GMM50]

You could also look at iPAQs. Even the older ones have USB support,
there is quite a lot of documentation available and there are lots of
used ones on eBay.

Are you aware that USB is not a symmetric protocol? USB devices have a
master/slave relationship hard wired into them, so a slave can't act as
a master. PDAs are always slaves, so your embedded device must be a
master.

If USB isn't already set in stone it might be worth looking at other
peer to peer interfaces, such as RS-232 or Ethernet because of this.
Most are quite easy to use e.g. Lantronics sell an RJ-45 Ethernet socket
that you can connect directly to the serial pins on a microprocessor and
you can get Ethernet adapters for iPAQ PDAs.

Hi Martin:

You hit the nail right on the head ("elementary my dear Watson...").
We've been through all the steps you outlined. Our current designs
have either an Ethernet IC (LAN91C111) or USB Master/Slave IC
(Phillips ISP1161). If we need RS232 we'll use the USB-RS232
converters.

The plan is to use JAVA for the 'slave' application. Some of out
products connect over the ethernet while others might be used with a
hand held (USB) in a mobile environment.

So we're looking for popular/easy to use recommendations for hand held
devices.

thanks
george

 

[Martin Gregorie]

The plan is to use JAVA for the 'slave' application.
>

My bad - didn't notice that in your original post.

So we're looking for popular/easy to use recommendations for hand held
devices.

I think I'd still recommend an iPAQ. I have an older 3630 that's used
for running the XCSoar flight computer. I like its screen clarity,
brightness and resolution, but am less fond of MS Pocket PC's GUI: some
stuff, e.g. File Explorer, is decidedly non-intuitive and worse, doesn't
work like the manual said it does. iPAQs are easy to buy (both new and
used) and good documentation of their internals is available. If USB
doesn't meet some requirement (e.g. transferring programs or big data
files) you can fit an expansion sleeve and put CF cards, Ethernet
adapters etc into the sleeve's slot.

I've also used a Palm as the control interface for embedded programs on
model aircraft, but only very old ones (mine is an M105). I find the
Palm harder to read (fairly low res monochrome screen) than the iPAQ
though I prefer its GUI and find the "gesture" pad pretty easy to learn
and use. The monochrome display is readable outdoors in bright sunshine,
which is more than you can say of many full colour displays. I don't
think the Palms have the expansion capability of the iPAQ, but I'm quite
prepared to be proven wrong.

As others have said, you'll have to use MIDP rather than the standard
J2SE development kit, but that applies to all PDAs and I guess you know
that already.

HTH