OT: Interface PDA to AVR project

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A project being designed has some data-logging functions (recording certain events, maximums, minimums, and the like), but is otherwise standalone in a factory/warehouse environment. It has no user interface (display, switches, LEDs) and is battery powered with the batteries expected to last the life of the product.

The customer would like a technician to visit each device periodically and upload the event log. This could be done with a laptop or PDA. I'm exploring the PDA angle right now.

And I'm a PDA novice.

Requirements (open to discussion):
--"Mainstream", neither bleeding edge or likely to be totally obsolete in 6 months
--Reasonably priced. Low volume, moving about in the factory, run over by forklift, etc. means we don't need/want top of the line.
--Interface to our AVR project
--Interface to Windows PC for upload & processing.

Digging on computer store Web sites, I see several offerings in the US$100 range (OK), Palm OS (mainstream--OK), USB + infrared serial interfaces standard (the crux of the post).

I assume the USB on the PDA is USB-slave.

So, how would you interface your battery-powered AVR to the $100 PDA? Can I easily talk to the PDA USB? What about that infrared serial?

Relatively low volume, so I don't want to spend 3 months on PDA and/or PC interface software, either.

TIA. Lee

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Hi Lee,

First let me say I know Nothing^2 about programming Palm, but I was looking at it as well. There is a website called http://www.palmsource.com where you can register for free, and get information on the Palm OS programming.

-Colin

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Interfacing with USB using an external controller such as an FTDI FT245 or FT232 is relatively easy, and they are fairly cheap chips ($6 a piece or so, plus $5 worth of external componants). Interfacing with infared though, thats just as easy but its even more inexpensive... maybe $2 worth of parts.

I am not sure if you will be able to use the USB controller, though... I would imagine its a slave-side USB controller, and the FTDI parts are ment to be slaves... But infared sounds like a good bet. In fact, it would be easiest to use the same infared setup between AVR/PDA and PDA/PC.

-Bill Carlson

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Correct me if I'm wrong, but if you have a slave-side USB (via FTDI) hooked up to the AVR, then couldn't you just interface directly to the laptop and skip the PDA altogether?

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Eric--

I'd rather use the PDA as the "walking around [hand-held] tool to check the devices" rather than a laptop if it makes sense. The application would be kind of like meter reading but on a much smaller scale. The laptop is bigger, more expensive, and works much easier if you have a place to set it down, or at least sit. The hand-held is ... well ... hand held. :)

In either case the data needs to be stored and processed on a network server and database. I consider hooking the laptop to the network for the task and "syncing" the data from the PDA to be equivalent.

Using the laptop, the "problem" has already been solved by us. Serial RS232 or RS485 links to PC serial port or USB-to-serial converter is one way, and we have already applied the FTDI solution for a slave device with a PC master. the PDA is a whole new ball game for us.

Lee

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Lee,
Most of the Palms/Visor have a serial port, some have USB. The Visors seem to favor a 3 volt ttl serial, while the Palms go rs-232. Since all the models are different you may have to determine which interface you want and go after that model PDA. This assumes you go serial.

Not all PDA's have USB so same rule applies, make sure the PDA supports it.

I believe the Palm OS supports IRDA, but don't know for sure. IR would have the convenince of no dongles or cables hanging off the PDA.

Once you have a database in the PDA, the hotsync process will get it into the PC, but you may have to write a conduit, if the database is custom. If you go CSV with a text file, the notepads could be used for the transfer but have a 2K limit in size. There are lots of database programs available for Palms, maybe one can be used for your transfer.

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Hi :

Look at this link :

http://www.bb-elec.com/palm/welc....

Regards,
Alejandro.

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Thanks for all the interest.

Candidates for the PDA after a first-pass scan:

1) CLIE™ SJ20 Handheld
Manufacturer: Sony
Palm™ OS® 4.1
Serial - Infrared (IrDA-SIR)
USB - Universal Serial Bus

2) Zire™ Handheld
Manufacturer: Palm
Palm™ OS® 4.1
Serial - Infrared (IrDA-SIR)
USB - Universal Serial Bus

Remembering that I'm starting with a clean sheet of paper, I'd like to explore the feasability of adding the IrDA-SIR capability to my device first. After that, some kind of adapter on the PDA to RS232 or RS485 and a cable link.

Has anyone done IrDA-SIR? Is it a power sucker (in idle)?

Does anyone know whether the PDAs have >>only<< the infrared serial, or is there a connector for a cable also?

Lee

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To my knowledge all PDAs come with a hotsync cable/cradle as not all computers are equipped with an IRDA port. The cable is either USB or RS232.

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Hey just another line of thought I'd like to add...

If the PDA is just used to extract the event log during meter reading for future reading by a PC, why not just design your own thing?
Just need a basic µC, some sort of comms interface, and a bucket load of memory eg compact flash, MMC. Maybe some form of user inteface as an option... download trigger button, LEDs and/or LCD or u could provide that as part of the logger unit. Being custom you could make the comms links as simple as u like!

Who knows...just a thort.

Steve

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"why not just design your own thing? ..."

That's what our hardware designer suggested (surprise). I'd rather not unless I have to: Limited "market"/production run, probably only one hundred or so; Short time to comletion, so no time for a software project; Not particularly cost-sensitive, & the PDAs I'm looking at are only $99; Links & expertise can be used on other projects.

Further scanning leads me to try to use a PDA that has a general-purpose (i.e., straight RS232 to generic) modem connection. Then I'm 90% of the way there.

Lee

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I know it's a different thread......but maybe you could use a Butterfly for your use interface.

Jeff
www.jldsystems.com
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Jeff Dombach, JLD Systems
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Check out NS Basic for PALM OS. This is suppose to be visual programming and has built in interface via infrared. You should be able to write a small program under PALM OS in NS BASIC to handle your interface with your AVR project.

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I recomend that you use IRDA Comm. This is built into the palm OS and you can get an off the shelf "gateway chip" from microchip

Palm GCC compiler:
http://prc-tools.sourceforge.net/

Fixed Speed 9600 Baud IrDA Protocol Stack Controller:
http://www.microchip.com/1010/pl...

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Has anyone interfaced a serial IrDA dongle (eg iFoundry, formerly Extended Systems, or Actisys) to an STK500 or STK501?

Thanks,

Doug Hewett, CSDP

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Has anyone interfaced a serial IrDA dongle (eg iFoundry, formerly Extended Systems, or Actisys) to an STK500 or STK501?

Thanks,

Doug Hewett, CSDP

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Resolved.

The STK500 com port labelled "RS 232 SPARE" has only rx, tx via port D and the DB9(S).

The dongle requires additional signals. It may be possible to connect the dongle to the STK501 via port E but we are not going to try this.

(We connected port D (and a 16x baud clock) to our in-house Ir assembly. It works.)

Thanks,
Doug

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The "dongle" you refer to--is that the iFSYS?

Lee

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Hi everyone!

I just read about your Palm-AVR interfacing efforts - very interesting
project!
Actually I thought about interfacing my old Palm Vx to an AVR
(e.g. 2313) to do some in system programming
(fumbling around with automotive applications it would
be interesting to do some data logging and update
programming like changing data and parameter sets as well).
To keep it simple (KISS) I´d rather use the parallel mode
to interface the devices...
Coming along on the automotive rather than the electronic
approach (don´t get me wrong here - got my experimental board
all soldered up and working - http://www.rowalt.de/index.htm -
and slowly start sucking diesel on the Bascom side - assembler and
the "C"s are yet to come on learning by doing) I really appreciate
any information available on software and hardware (MAX232?!?)
hints from your experienced side!

Thanx for your help already now!

Best regards

Dolphi