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This method gets my vote.

- No special equipment required

- Best for nontechnical users because it simply involves putting in a card and powering up

- Your system can do an integrity check on the entire file before starting the flash operation without needing to have it all in RAM

- The previous firmware rev can be written back out to the flash device for rollback purposes if necessary

In a lot of cases, making the ARM a DHCP server and just plugging in a crossed-over Ethernet cable into the PC will work, then ftp/tftp the data over to the ARM... ;)

pete

--
pete@fenelon.com [Support no2id.net: working to destroy Blair's ID card fraud]

Well they will need a card reader but they are only pennies these days.

That does appeal but will require the user to access the rear of the system (which is panel mounted) but this isn't a huge problem and USB or ethernet connection would require this also.

This highlights one of the draw backs of this method because it will require a file system. However, I don't think that it's too much of a headache to implement or I could just buy one.

This is possible with all the methods but compact flash certainly is the most convenient for that. At the moment I am also drawn to Bluetooth because it seems fairly simple and has the wireless convenience. However, ethernet also appeals because if it had a permanent connection then remote monitoring and other sexiness suddenly becomes possible. It still presents IT headaches though.

Thanks for your quick reply

Will I still have to pay for a MAC address or can I "borrow" one from somewhere else seeing as it's not going to be on a worldwide network (but what happens if it is?)

I said no "special" equipment :)

Or you can just use mine for free -

(please note there is an update coming soon to fix a couple of bugs that have been reported by people in the field).

It's a nightmare to implement if you're doing it yourself, and relatively expensive to buy modules that do it for you.

An SD interface at its simplest is three GPIO pins (clock, data in, data out) plus maybe one more for card detect.

That's ideal, many thanks for that. Your site is pretty interesting, by the way, particularly the vintage computing section. As I read through your list with a nostalgic tear in my eye it occurred to me that I think my dad still has a Sinclair QL in his attic in the original packaging. I'll have to check if it's still up there if that's something that might interest you. I think I've got some ZX81 software in original packaging (probably unused) that I could look out and I probably have a ZX81 but I think I might keep hold of that for my own nostalgia :)

It all depends on how expensive it turns out to be. I don't mind $30 or so per unit to buy the convenience of the wireless link but any more is going to be too much.

192.168.0.x are basically pre-allocated for local use: they won't go through a remote router. Something in that range should work.

Superb. I guess there may be trouble if the customer's local network isn't set up all that well but we can't cater for every eventuality.

I've just spotted that IrDA will work up to 4MBps. The existing system already has 19.2Kbs IrDA which has worked well. Does anyone have experience of using such data rates and how reliable it is?

That is one of the available private _IP_ address ranges. Unfortunately, there are no such ranges for MAC addresses. Those should be bought or, as suggested, borrowed from, for example, an old ethernet card that will be scrapped after the MAC has been read from it.

--
Stef    (remove caps, dashes and .invalid from e-mail address to reply by mail)

"Probably the best operating system in the world is the [operating system]
 made for the PDP-11 by Bell Laboratories." - Ted Nelson, October 1977

Any idea how much it costs to buy, say 1000, MAC addresses?

Hmmm first you talk to IEEE to obtain either an OUI or IAB, where OUI gives 3 octet company identifier and 3 octet you assign (24bit field). Alternatively you can get an IAB which is a block of approx 4097 addresses.

OUI is about $1,650 IAB is about $550

Other charges related to being Public or Private listings.

Maybe someone could get an OUI and sell blocks of 128 or 1024 as I believe somebody does but I cannot be sure on that.

-- Paul Carpenter | snipped-for-privacy@pcserviceselectronics.co.uk PC Services GNU H8 & mailing list info For those web sites you hate

IrDA speeds depend on the optics, and silicon/firmware support.

There is also a vFIR spec, at 16MHz, but silicon support is sparse at present - but that speed seems a natural match for USB.

-jg

IrDA is an optical link. Meaning you can have problems if a mosquito or the user's hand decides to fly right through your communication. Or some other IrDA device in the room could suddenly want to participate in that interesting discussion it's overhearing. I'd tend to be wary of such a feeble connection for risky operations.

As circumstantial evidence, consider that makers of mobile phones and similar gear offering IR links to PCs often strongly recommend using wire instead of IR for firmware updates.

--
Hans-Bernhard Broeker (broeker@physik.rwth-aachen.de)
Even if all the snow were burnt, ashes would remain.

This is simply not the case.

1. IrDA is not a pinpoint of light. It is a fairly tight cone, and unless that mosquito or your hand actually COVER COMPLETELY the transceiver window, it is highly resistant to blocking.
2. IrDA incorporates a link layer protocol that includes automatic retries. If a packet is lost or damaged, it's re-sent, simple as that.
3. IrDA protocols can and do recognize multiple devices, and will only carry out transactions with a specified device when multiple contacts are present. Also, IrDA is typically designed for short distance (~1M), line of sight use. This tends to prevent being "overheard", which isn't a problem anyway, and is certainly better than any comparable RF solution.

Then I'd have to say their implementation sucks.

I helped develop a portable instrument that relies exclusively on IrDA for critical file transfers (logged data) and firmware updates. Since its introduction, the primary support issue has been laptop manufacturers who ship their products with IrDA disabled in the BIOS by default, NOT failed file transfers.

Our product supports up to 115Kbps links (auto-negotiated by the IrDA link management, by the way), but that limit was imposed by the available clock to the UART, not IrDA.

I have used 4Mbps IrDA to transfer hundreds of files between a PC and a laptop that lacked an ethernet connection; it is extremely reliable.

--Gene

Hello Gene,

I was planning on playing around with IrDA on the PIC MCU's. I was wondering what is a good IrDA encoder chip (one that I can hook up directly to the USART at 115KBps).

Thanks

Should take 20 minutes. That's not too slow for an occasional upgrade

*if* the host application displays a believeable progress indicator, such as counting minutes until done. It is too long to sit at a simple 'please wait' screeen with no indication that it's not dead.

That probably is the best option of it's done frequently. Also with serial you may need to supply some customers with a USB-to-serial dongle anyway. Another option is to build one like the CP2102 ($5 from digikey) into your product - though that may not go all that much faster than a serial port. Or they may - hyperterminal just let me open a belkin usb-to-serial dongle (different chip) at 921600 baud, though if it actually works there is a mystery.

Put the card slot on the front panel then. Customer shouldn't program the card, you should and mail it to them. Don't use a filesystem, or at least don't use a standard one (use something very simple just capable of steering you around bad blocks). Program the card in a linux box and mail it, customer inserts it. No worry with customer pc configuration at all.

No way is JTAG faster than serial unless you have a specialized pod driven by USB or something ($100+) the classic cheap parallel port cable is bit-bang serial, wheras an ordinary serial port has hardware shift registers and hardware buffering. Note you don't have to give them jtag access to the processor, you could give them a jtag chain containing only a serial flash chip where your code resides.

One of the delights of having a unit that is field-upgradable is being able to deliver updates electronically _instantly_. Significant amenity is lost by doing things the way you describe.

It all depends on the industry and the product. Sometimes you want to send them a physical object by overnight delivery rather than mess with their computer. Sometimes you don't want them to be able to apply the same update to multiple units (yes, there are other ways of doing that), etc.

I'd probably not recommend having the customer remove a flash card and put it in a reader attached to their PC, unless that was something done in ordinary use of the unit. Either I'd hvae them download to the unit from the customer PC, or I'd send the customer an object to add to the unit. In some cases, I'd even considering sending out an 'updater box' that performs the download (and perhaps conducts some tests) which must then be sent back.