Customers Performing Own Upgrades. How Hard Can It Be?

[towlerg]

I you want this to be user friendly I don't think CDC (serial port emulation USB) is the way to go. You will find it problematic to determine which serial port (COM1:, COM2: etc.) is connected. I don't know the devices you currently use but porting to another PIC might not be as difficult as you expect. Provided that your code uses symbolic names for the various components inside the PIC and no magic numbers it shouldn't be that tough.
Why not try a port before you burn your bridges? I'm curious, could you list precisely which PICs you use of the families you mentioned?

George

I had a quick look at the data sheets of the devices you use, do you use the Motion Feedback Module in any of your products?

[towlerg]

Sorry I can't edit my previos post.

Had a play with MAPS and I think I see your problem, the 18F*6K22 has a 12 ADC and 18F*431 has Motion Feedback Module. There are no PIC18F's with USB and Motion Feedback Module. There are however, 17 PIC18F's with 12 bit ADC and USB. If you are using the MFM then you have no choice but to go serial.

Most PC's don't have serial ports so that might help you find your emulated one. If not, you're going to have to ask the user or maybe trial and error?

George

[timmers]

We use the 18F26K22 / 46K22's because they have two serial ports and are backwards compatible with the 16F876/877 which we used to use. (albeit the analogue/digital configuration has to change)
The 18F2431 / 4431 (with motion feedback module) are used for motor control.

The MFM module tracks the quadrature counts (QC's) for position, and by using a known time interval, velocity. The Microchip velocity measuring module is a waste of space!

[towlerg]

Sorry I don't follow, do you use the MFM in your app?

I can see why you are unwilling to port to another PIC but the downside of using CDC is substantial.

An alternative might be to add USB hardware to make a HID connection.

George

[timmers]

... do you use the MFM in your app?

Eventually we would use it in future products requiring customer upgrades. At present it's a return to base upgrade.
I would like to get the *6K22 working first!

[rsocor01]

For a tipical individual that wants to upgrade the programming in their PIC, I don't think the Microchip Bootloader program would be that complicated for him. If you create a good tutorial with pictures on how to use the Microchip Bootloader, I think that that's the way to go.

[towlerg]

@rsocor01 I suspect that the target user wouldn't know a PIC from a pick.

@timmers There are many PIC devices similar to *6K22 with USB builtin but I suspect you have already decided against porting. In which case CDC must look very attractive but I would suggest falsely so. Just a couple of ways that you can have HID, a cheap PIC with USB as a buffer or maybe MCP2210. BTW you do realize that USB bootloader is purely software.

Anyways, I leave you with this thought - CDC bad, HID good.

George