Development board help

[Sceadwian]

While all he needs is extra I/O in this case there's nothing bad about using two micro's. SPI isn't that difficult.

 

[Nigel Goodwin]

While all he needs is extra I/O in this case there's nothing bad about using two micro's. SPI isn't that difficult.

And serial is even easier, and can work on just one pin, bi-directionally if required.

 

[3v0]

I have tried to be delicate but have gotten no reply.

My take is that we have a user who has yet to blink a led talking about multi-uC's. My feeling is that until you have done some of the simple things you should not be looking this far down the road.

 

[Mr RB]

I love those 74HC595 chips. I bought a few sticks of them surplus for about 5c/chip, the only down side is that are SO16 package but still easy enough to solder. I've got some little SO16-DIP16 headers too for through hole use but usually just use the SO16 and solder to the PCB.

They only need 2 pins; clk and data to drive 8 output pins and no timing issues. And you can chain them as I said above. I really can't see why you'd mess with two PICs with 2 lots of software, 2 times you have to program them, 2 xtals, possible slow asynch serial clock rates etc etc??

 

[Sceadwian]

Nigel, SPI is much faster than serial, there's no possibility of baud rate missmatches and it's bidrectional as well.

 

[Nigel Goodwin]

Nigel, SPI is much faster than serial, there's no possibility of baud rate missmatches and it's bidrectional as well.

What do you want massive speed for?, feeding an LCD and reading a keypad are incredibly slow processes - there's no problem with baud rate mismatches (unless you deliberately write them, and why would you?). It's also easy to do bi-directional via serial using just a single pin, saving even more valuble I/O.

People seem to jump on I2C, SPI, and even the parallel port in one case as ways to transfer data between two PIC's, serial is much simpler than all of them, and for most cases exceeds any requirements for the data transfer.

All communication methods have their uses, but what's 'best' for a particular application isn't always obvious.

 

[fromansr]

I have tried to be delicate but have gotten no reply.

My take is that we have a user who has yet to blink a led talking about multi-uC's. My feeling is that until you have done some of the simple things you should not be looking this far down the road.

Your right 3v0, but I still need to plan my project before diving into the implementation.

I've also hit another problem...Is it possible to operate a SPI IC and 12C IC simultaneously using 1 micro?? I'm a bit confused by the micro (16f887) data sheet...

 

[blueroomelectronics]

I was just looking at it!!!

The unicorn seems like an option...but I already have an LCD
Bill, if your out there, a recommendation would be helpful.....

Guess I'm late in seeing this post.

The Unicorn supports two types of LCD. A 2x16 LCD and 128x64 GLCD it doesn't include them. There is support for an external 4x4 keypad on the bottom.