PIC to PIC TX RX and PIC to PC COM RX ..a little help please

[mackrackit]

Thank mister e for the MultiCalc, I use it often.

http://melabs.com/resources/samples/pbp/usart.bas
Play with the above to get started with the USART. Notice they did not use DEFINES.

The program will echo your keyboard with one PIC connected to a PC. The terminal program that is part of MCS is good for this setup. I think the above sample is for 4Mhz. So check the values with MultiCalc.

Keep us posted...

[Dennis]

Hi dave

Thanks again :-)

For my 16f887 i have the following set for using the internal clock

OSCCON = %01110001          'Int CLK 8MHz
ANSEL = %00000000           'All digital
OPTION_REG.7 = 0            'Weak pull-ups enabled

DEFINE OSC 8                '8MHz

So I use 8 MHZ not so ?

For the 184520 the following is set

'Ocsillator selections here
        OSCCON = $70            'Int CLK 8MHz
        OSCTUNE.6 = 1           'PLL 4x
        ADCON1= %00001111       '$0F = disable A/D converter
        cmcon   =   7 
        INTCON2.7 = 0     'switch pull-ups ON
'END of oscillator selections
  'timer/oscillator defines 
        DEFINE OSC 32            '4x 8MHz
'END of timer/oscillator defines

So do I choose 4MHz or 32 MHz ?

thanks a million

Kind regards
Dennis

[mackrackit]

For the 887 use 8Mhz for the calcs.

I am not sure about the 4520, I have not used USART with PLL enabled.
But...
I think the USART uses the primary OSC so try 4Mhz. 50 50 chance of it working

[Dennis]

Hi Dave

Could I set both PICS to 4 MHz internal OSC ?
And once it's working try variations ?

[mackrackit]

That would be the way to trouble shoot.
Just make sure they are running at the expected speed with a blinky and a stop watch or meter if you have one..

[Dennis]

Hi again Dave

I think I am almost ready for the next step ....
RF and RF module TX RX
I have been reading posts all through the forums, even some of yours from years back ...
Now for the next step ... to try the same or a similar thing without the wires.

Should I start off with sering or plunge straight into HSER ?

The plan is to be able to send 3 bytes using the most reliable method.

So the question is where do I start and what do I start with ?

Kind regards
Dennis

[mackrackit]

So do I choose 4MHz or 32 MHz ?

I have it on good authority that the PLL speed is the one to use. Thanks Bruce!!!

What radio modules are you using? I have only used the ones from rentron.com.

As for reliability, all of the serial methods (HSER,SER,SER2..) are good. Are you planning to use interrupts with the serial input or just wait and time out, check later sort of thing?