Help with pic16f690 -max232cpe

[ScaleRobotics]

Can you post your entire code with the trisb and all ... plus whatever code you are using to determine it is not receiving.

Thanks,

Walter

[krise86]

DEFINE OSC 4

ANSEL = %00000000 ' Pins to be Digital
ANSELH = %00000000 ' Pins to be Digital
TrisA = %00000000
PortA = 0
TrisB = %00100000 ' if the only input is pin 10 Rx
PortB = 0
TrisC = %00000000 ' if none of the portC pins are used
PortC = 1

CM1CON0 =0
CM2CON0 =0
CM2CON1 =0

adcon1=0

Include "modedefs.bas"

DEFINE HSER_RCSTA	90h
DEFINE HSER_TXSTA	24h 'sets bergh = 1 or 20h sets = 0
'define HSER_BAUDCON 1h ' 0h
DEFINE HSER_BAUD	2400 '16468
DEFINE HSER_SPBRG	103
DEFINE HSER_CLROERR 1
rxVal Var word

start:
Hserout ["Hello World", 13, 10] ' Send text followed by carriage return and linef
main:
Hserin 10000,start,[rxVal] ' Get a char from serial port
Hserout ["Got value:", rxVal] ' Send char out serial port
pause 30
goto main

That's the code.

[mackrackit]

DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive
DEFINE HSER_TXSTA 20h ' Enable transmit, BRGH = 0
DEFINE HSER_SPBRG 25 ' 2400 Baud @ 0.17%
DEFINE HSER_CLROERR 1 ' Clear overflow automatically

The above should be for 4MHz.
Can you also post your configs and what are you using for an OSC?

[krise86]

I have already tried that, so it's still a no go.

But no one has commented on the voltage levels of the max. it should say 10 but i dont get it higher than 7. when i rebuild the whole shematics on the breadboard the voltage got i little better but still no higher than 7

[aratti]

But no one has commented on the voltage levels of the max. it should say 10 but i dont get it higher than 7. when i rebuild the whole shematics on the breadboard the voltage got i little better but still no higher than 7

Check the capacitors used. See snap attached for value.

Al.

[Dave]

krise86, Depending on the capacitator values used with a MAX-232 the charge pump voltages should be around +-6 volts to +- 9 volts. The TRUE RS-232 spec calls out for mark,space voltages of +- 3 volts minimum... Some laptop computers now days do not meet the TRUE RS-232 spec limits as some only put 0 to +5 volts... That is why some laptop computers don't have a solid serial communications...

Dave Purola,
N8NTA

[krise86]

Yeah i am using 1uf caps, so it's not that. and i am reciving at this moment v- = -1.86 and v+ = 6.96.

I found out that i can use the pickit 2 as logic analyzer. and i see the bytes roll inn when the pic send out to pc but not ther other way around.

Im stumped... this sould work!
I have followd all the guidelines and shematics and caps. i have also oredered some new max and pic's. also alot of caps and resistors. I really want this to work.

Thx for all the help so far. i will get this to work! i hope