h-bridge problem

[vision]

hi,

I'm a beginner in this amazing world of PICs and I have encountered 2 problems in controlling a dc motor direction...

1. I used this H-bridge to control my motor (see attachments) and works fine while adding a voltmeter across the output but when load it with any load e.g my 9v motor the voltage decreases to a value of 0.01v and couldn't drive my motor.

2. I wrote this program that reads a potentiometer value ,if this value is greater than 12kohms turns the motor CW, less than 12k ohms turns the motor CCW:

device=16f84a
dim R_Value as byte
trisb=%00000001

start:
portb=0
r_value=pot portb.0,153
if r_value > 65 then goto rotate_lower 'Making motor rotate CW
if r_value < 59 then goto rotate_higher 'Making motor rotate CCW

Rotate_Lower:
portb.1=1
delayms 250
goto start

Rotate_Higher:
portb.2=1
delayms 250
goto start

the program worked but instead of comparing the value to 12 k ohms it performs this operation at 1.2k ohms (I have checked my scale!)

any help will be appreciated, thank you

[skimask]

Have you tried some Google-ing on the subject yet?
What did you come up with?

[mister_e]

Have you tried to use the right forum?

And your circuit will NEVER work.

AND i suggest you use a newer PIC... not a museum part

AND YES I HAD A BAD DAY

SORRY

[Armando Herjim]

I think you should try to make a google search like they suggested. I guess your problem is that your motor requieres more much current (A) that your H-Bridge can handdle... or maybe you just need somo clamp diodes.... try clamp diodes on google...

Good Luck.... to you too stev!

Armando Herjim.

[Archangel]

Hi Vision,
Looks like your schematic has the diodes reversed biased, I'm not sure you even need them try reversing them or jumpering them and see what happens, I haven't even looked at your code, I assumed the others did.
JS
edit
mister_e I see what you meant about using the correct forum, what manner of basic is that? Looks like a cross between c and basic. JS

[vision]

thanks all of you for your replies...

Yes I tried Google search but in vain , Well I'll try again

Actually I thought about adding my question in the schematic forum ,but thought about the PIC problem....

mister_e: why my circuit will never work ? Is there something wrong?
and please don't make your bad day affect your welcome to the newbies