solar tracker controller

[ultimatekiller]

Hi all,
I m a new member... and i m now doing a same project too... named "PIC microcontroller solar tracker"... Does anyone has the circuit or schemetic of the solar tracker?? and some explanation of the circuit?? i need that badly... Thx...


Regards,
Ultimate Killing Machine

[muzakyo]

hello
can anyone check my proramming
i am doing the same project.....

solar tracker
pic 16f877
2cds with dc motor

v1 var byte                       'variable v1
v2 var byte                       'variable v2
v3 var byte                    'variable v3


TRISA = 1                       'Set all PORTA pins as inputs
TRISc = 0                     'Set all PORTc pins as outputs

start:

pot porta.0,255,v1             'Read 1st CdS Sensor (east)
pot porta.1,255,v2            'Read 2nd CdS Sensor (west)

if v1 <= 230 then skp        'start program
if v2 > 230 then slp        'is it dark enough to sleep? (sleep mode)

skp:
if v1 = v2 then start        'If equal, do nothing
if v1 > v2 then greater        'If greater, check how much greater
if v1 < v2 then lesser        'If lesser, check how much lesser

greater:                    'Greater routine
v3 = v1 - v2                  'Find the difference
if v3 > 10 then cw             'Is it within range? If not, go to cw
goto start                    'In range do again

lesser:                        'Lesser routine
v3 = v2 - v1                'Find the difference
if v3 > 10 then ccw            'Is it within range? If not, go to ccw
goto start                    'Do again

slp:
low portc.0                       'stopping the solar tracker for moving 
low portc.1                    'stopping the solar tracker for moving
goto start 

cw:                            'Turn the sensor array clockwise
high portc.o                  'Turn on h-bridge
pause 100                     'Let it turn for a moment
goto start                    'Check again

ccw:                         'Turn the sensor array counter clockwise
high portc.1                   'Turn on h-bridge
pause 100                     'Let it turn a moment
goto start                    'Check again

end

[Dave]

Muzakyo, I don't see where the motor is commanded to stop.. Must operate like a windshield wiper unless it's asleep?

Dave Purola,
N8NTA

[muzakyo]

i am a newbie in pic......

but from the proramming the motor will run for a certain time (100 miliseconds) and then it will get back in the start loop....

for the motor i am not sure.... but when i compile it there are no problems.

did i need to do like the slp: programming..?

for this program i refer to the pic microcontroller project book by John Iovine and pic robotic : a beginner's guide to robotic by john iovine... (first post)

[Dave]

muzakyo, I don't see anywhere in your code that you are stopping the motor if your system is "on target". You need to place some kind of DEAD BAND limits that are within the ON TARGET criteria. I mean +- so many counts... You should have at least 4 states, 1 for sleep (waiting for next morning), 1 for going east, 1 for going west and 1 for stop during the day when system is on target.

Dave Purola,
N8NTA

[muzakyo]

sorry my lack of knowledge....

for the system when the system are on the target is

skp:
if v1 = v2 then start 'If equal, do nothing

it will go back to the start..... then it will never give output to the motor (so motor will not rotate anywhere) until one of the cds value higher than other.

so to stop the motor when it run

cw: 'Turn the sensor array clockwise
high portc.0 'Turn on h-bridge
pause 100 'Let it turn for a moment
low portc.0 'turn off the h-bridge
goto start 'Check again

what do u think....

can u give idea how to improve this proramming

[Dave]

muzakyo, Yes that is more resonable.... Just don't forget to do the same for the other direction as well...

Dave Purola,
N8NTA