PIC16F877 & Serial Comms

[G4LCH]

Hi Guys,
I am using a 4MHZ 877 with Debug and Serout And Serout2
I have in the latter cases added the mode include to get the correct modes
and ensured that the fuses are set correctly.

A simple routine returns rubbish in the terminal just as debug does

nCounter Var Byte

For nCounter = 1 to 10000
SerOut PORTC.6,N2400,["Hello"]
Pause 3000
Next

I have added the required declare statements as well

Define osc 4 ' We have a 4MHz Clock here

@ DEVICE pic16F877,XT_OSC
@ DEVICE pic16F877,WDT_OFF
@ DEVICE pic16F877,PWRT_ON
@ DEVICE pic16F877,LVP_OFF
@ DEVICE pic16F877,CPD_OFF
@ DEVICE pic16F877,PROTECT_OFF

and used @ DEVICE pic16F877,WDT_ON


DEFINE DEBUG_REG PORTC
Define DEBUG_BIT 6
Define DEBUG_PACING 3000
DEFINE DEBUG_BAUD 2400
Define DEBUG_MODE 0

And altered to inverted in the right state when not using Max232CPE Interface
that does have the correct voltages with 1uf caps on the charge pump pins.

and it still gives Garbage a loop back test works fine on both my PC and the Macintosh so I know that my cable is correct.

is there anything else I should be doing as Visual Basic is reporting framing errors, I adjust the Parity, Stop and data bits to no avail.

A loopback either side of the MAX232 Interface works fine as well so I know that using this test and the scope that the voltages are correct, I have also tested (visual) with my break out box and the signalling is fine.

Do I need any pull-up resistors on the ports ?? nope it still works the same way, I have also sent hex out and viewed the stream in hex mode and its garbage.


any ideas guys ??






This is driving me nuts

[G4LCH]

The debug statement also gives garbage
Mark

[sean-h]

With Serout you need to include this at the top of your code:

Include "modedefs.bas"

N2400 will invert the bits so you can just use a resistor straight onto the serial port.

If you have a max232 then this inverts each bit and you want to send it in True T2400

Regards

Sean.

[G4LCH]

Sean As I said in my note I have the modedefs in there and it compiles 100%
I have also tried it direct with 1k resistors and via an interface and i get garbage in all cases.

Mark

[G4LCH]

With the debug command I have also tried to use 4800 Bps and both inverted and non inverted with no luck still garbage.
Mark

[sean-h]

Mark you say you are using VB.

Have you simply ran up hyperterminal, set the com port to 2400 8 n 1, hit retunr to open port and then looked for the data, this will illiminate another step if the data is clear and then it has to be the VB side of things.

Regards

Sean.