18f8722

[garret]

hey all, Mel and gang,
I'm just jumping into the 18F range from the 16F. I would love to hear from anyone about the differences, major and minor, between the implementation of the two. I have the manuals already, i suppose i'm looking for the head ache level and whatnot......
I would love to get from someone a basic code that has actually run well on something like the 18f8720 or 18f8722... even if it was only a blink...Thanx All...

[Melanie]

The only consideration is that you will use Microchips MPASM Assembler (if you don't already do so) instead of MeLabs PM. This entails a bit more fiddling with Configuration Fuses (which on most 18F series are quite convoluted) and a possible edit of the respective 18F's .INC file in your \PBP directory. Beyond that, it's Datasheet time... For example Microchip have a habit of sneaking in additional features into the 18F series which may or may not require some small changes in your handling of internal Registers. The progression path for the 16F876 is to go to 18F242 and 18F252 - a reasonably painless transition... but to progress from say 18F242 to a 18F2420 (because you don't want to use an external Resonator) becomes a bit more tricky because internal Register assignments for unrelated things like the ADC have unexpectedly moved... Datasheet!

[garret]

Nice to hear from you again. Well, I'm really attracted to the 70pin i/o on these chips. I've got a large instrumentation panel coming up and it would seem I can do it all on the one chip if I can get it blink straight.
I wonder what happened to the 18F8720... It seems they retired it for the 18F8722. And at such a young age....makes you wonder.....

[garret]

Does anyone know of any development boards or even break-out boards for these 80pin TQFP chips... Sure would be a big help.

[Stump]

I regularly use the smaller brother to this chip (18F6722)
I have found no surprises migrating from 18F452 and 16F677.
The chip is very stable and does exactly what the data sheet says.
Note that there is an additional register to set up for the extra a/d.
The 22 version is a good upgrade to the 20 version adding low power
and enhanced everything and internal oscillator.
I designed inhouse, a "brain" module that houses the chip and xtal on a small
board with dual rows of pins (like a stamp). This allows this module to port to any project and freedom from re-doing the chip layout each project.
Melabs has an adaptor for the 18F8722
http://www.melabs.com/products/adapters/surfadpt.htm

[G8RPI]

Hi,
Roth Electronik do a range of break out boards.
The RE450 would seem to do what you want.
See Farnell stock no 305-7185
http://uk.farnell.com/jsp/endecaSear...=3057185&N=401

HTH,
Robert G8RPI.

[garret]

looks great