How to do a field firmware update?

kbruin79 · Joined: 02 Aug 2010 Posts: 30

Hello,

I am working on a small handheld device that uses a pic16f1939 and would like to know how to allow customers to perform a firmware update on this device?

From what I read, I could use a usb to serial converter and have a bootloader running on the chip but where can I find a reliable PC software interface that takes the hex file to communicate to the pic?

I have looked at a list of free open source ones, the problem is they have limited device support and not very user friendly.

Any suggestions on a reliable user friendly PC interface ?

Thanks in advance.

newguy · Joined: 24 Jun 2004 Posts: 1907

The CCS load-n-go fits the bill. Sell one to the customer and have them install the CCSload program on their PC. Then just email them the hex file. They start up CCSload, download the program to the load-n-go, then use that to program the device. If it's possible or feasible for them to drag a laptop out the device, then a ICD-U64 is less than half the cost of a load-n-go and uses the same program (CCSload).

kbruin79 · Joined: 02 Aug 2010 Posts: 30

ckielstra · Joined: 18 Mar 2004 Posts: 3680 Location: The Netherlands

The CCS Load-n-Go at $199 seems expensive to me for a user to do firmware update.
An ICD-U64 at $89 is half the price, but still a lot of money when you just want to do a firmware upgrade.
The Microchip PicKit3 can be configured as 'Programmer-to-Go'. Download the firmware on it, send to your customer. The customer connects the device and presses the button on the PicKit3. Ready. No PC required. costs $45

But... as a normal user I can't remember when I had to buy special equipment for upgrading my Phone, router or other consumer device. This can be achieved though the use of a bootloader firmware in the PIC and a program on the PC.

Many of the free PIC bootloaders use the bare hex-file as input transmitted from the PC over RS232 by a program like Hyperterm, Telnet, Putty, etc. This works and is OK for technical persons like us, but not something I would have done by a normal user. More professional is to hand the user a dedicated loader program; there exist several like that but most have closed source for the PC program.

It seems like not a lot is happening in bootloader developments, searching the internet I find many old (abandoned ?) projects.

Tiny PIC Bootloader has been around for a long time and has proven itself. Free. I like the protocol it uses to the PIC which supports several commands, including reading memory and setting fuses. PC source code is not available, too bad because I'd like to simplify the user interface even more for the standard user.

A fork from the Tiny PIC Bootloader with all source code available can be found on Google Projects: http://code.google.com/p/pic-bootloaders/ but even this project had it's last update two years ago (Dec-2010).
It is a console tool, not my preference as it makes it more difficult for the user to specify the COM port number (not many users know how to figure out the correct COM port number nowadays). A nice feature though is that they provided for embedding the firmware into the code, so you can send your users a one-click tool.

Perhaps it is best to take the bootloader firmware of the Tiny PIC Bootloader, reverse engineer the protocol and then write your own PC application.

Also have a look at Microchip Application note AN1310 - High-Speed Bootloader for PIC16 and PIC18 Devices

newguy · Joined: 24 Jun 2004 Posts: 1907

bkamen · Posted: Tue Jan 22, 2013 5:49 pm

If you look in the CCS library, there's a serial bootloader.

From there, you can use the wonderful Windows GUI based SIO.exe which is CCS's loader that runs from a PC.

I don't believe it's free to give away -- but has a very low licensing fee.
You could sell that to your customer and then they'd use ANY serial port they can come up with (USB or legacy) to field program a PIC.

Call and talk to CCS -- but you can also look at the bootloader which is included with PIC-C in the meantime.

Keep in mind, your device also needs to support self programming.

-Ben
_________________
Dazed and confused? I don't think so. Just "plain lost" will do. :D

temtronic · Posted: Tue Jan 22, 2013 7:25 pm

.. you've opened up a 'can of worms'!
Firmware updates are usually disasters waiting to happen.
No such thing as 'a reliable user friendly PC interface '.

Whatever path you choose, beta test 'the system' with REAL people NOT techs! Grab mothers,uncles,old guys, and let them read your onscreen instructions and see if THEY can get the job done. NO prompting, no verbal suggestions(cough,cough,ahems allowed).REAL tests with REAL people.
I'll lay odds you'll reevaluate your first attempt 3 or 4 times.

good luck !
hth
jay

bkamen · Posted: Tue Jan 22, 2013 7:48 pm

newguy · Joined: 24 Jun 2004 Posts: 1907

Ttelmah · Joined: 11 Mar 2010 Posts: 19467

Also, if you use either a bootloader, or your own programmer code, 'device check' your file. So if you have (say) a hex file that is for your product 'controller-X, version 3', have each controller having an board ID number, and make your code check that the ID on the file, matches the one on in the device, before it'll allow you to proceed. Avoids the disaster where code for version 3 hardware is loaded into a version 4 board, by somebody who doesn't read the 'limitations' page, or who thinks "I'll be smart", before uploading.....

Best Wishes

CHCHPIC · Joined: 15 Aug 2012 Posts: 1

As a comment, A few years ago we approached the developer of Tiny PiC Bootloader and for a small cost, it think it was 50 euros he provided the source code for us to modify.
We have been successfully bootloading new firmware on our sites in New Zealand over an RS485 bus for 3 years will little trouble.

Regards

Mark