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PIC 16LF84A instead of PIC 16F84?

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fever

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hello all,
iam building a stepper motor controller for my small CNC.i found below design which can control 2 motors per chip.http://www.dakeng.com/u2.html
but the design here uses PIC16F84 where as i have plenty of PIC16LF84A.so can i burn the same code(http://www.dakeng.com/u2source.zip) on the *LF chip.will it work?
i modified the circuit to handle more current.pls have a look and tell me if i did any mistake.
 

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Yes, it's just a version that works to a lower voltage level.

As for your modifications, it doesn't look like you have much current available to feed the TIP's?.
 
thanks goodwin.
actually the original design uses 2n2222.i replaced them with TIP120(2) as i thought it will handle more current.so do u suggest any modification or replacement so that the ckt can handle little more current?
 
fever said:
thanks goodwin.
actually the original design uses 2n2222.i replaced them with TIP120(2) as i thought it will handle more current.so do u suggest any modification or replacement so that the ckt can handle little more current?

Sorry, the picture was shrunk on my monitor, and I thought it said TIP20, not TIP120 - the 120 is a darlington and should be fine.
 
i have some more dumb doubts.i hope u don't mind.
1.does this chip consist of internal clock(as i don't see any Xtal there)
2.and in the ckt explanation i says MCLR must be held high for normal operation.so i connected it to +5v with a 10K resistor in series.is it ok?
3.some one said 4050 is not necessary between TIP120 and PIC.is it right?

overall i want to keep my parallelport as safe as i can.so pls guide me that way.
thanks
 
fever said:
i have some more dumb doubts.i hope u don't mind.
1.does this chip consist of internal clock(as i don't see any Xtal there)

No, it uses an external RC (on pin 16) as the oscillator - but you could use it's modern replacement (the 16F628) which does have an internal oscillator.

2.and in the ckt explanation i says MCLR must be held high for normal operation.so i connected it to +5v with a 10K resistor in series.is it ok?

Yes.

3.some one said 4050 is not necessary between TIP120 and PIC.is it right?

No it's not, but you need a series resistor to limt the current.

overall i want to keep my parallelport as safe as i can.so pls guide me that way.
thanks

Should be fine.
 
For a stepper motor, should the diode's anode connected to the collector and cathode to the Vcc to avoid back emf of the coil?
 
for above design,TIP120(2) consist of internal diode.so i don't think we need separate diode for each coil.
this is the final ckt that iam going to built using TIP120(2),PIC16LF84A
**broken link removed**
 
but the internal coil cannot avoid the back emf that coming from the collector of the transistor, right?
 
Would depend on the built in diode's charactoristics.
 
If the TIP120's actually contain internal diodes though it's just one extra component you don't need. The biggest considering would be the recovery charactoristics of the internal diodes and the driven frequency.
 
well i tried to built this.but like fever i used PIC16LF84A instead of PIC16F84.and i used NOPPP to program it.programmer said chip has been programmed and when i connect it to the circuit nothing happed.
am i going in the right way? what is this "A" stands for ?
i used TIP122.may be i shld use 2N2222 as per the original design.and for motor i have 6 wire stepper.so i joined two center taps and connected it to +12v and other 4 wires to collector's of TIP122..
 
i used PIC16LF84A.
burned it using NOPPP programmer.it said programming is success.
then i connected the circuit as fever shown.imean PIC to motor via. TIP122.but nothing happened.
mean while i searched over net for more details of this project and i found this dutch page.**broken link removed**
i tried to translate it(but did't understand some points)
so the guy used ULN2003/ULN2803 instead of TIP122 and 4Mz Xtal instead of just capacitor.and he built the machine very well (http://www.circuitsonline.net/forum/view/4354/8)
 
more search more info.
i found some more data for dankeng PIC16F84A based stepper controller.
in this design 2N2222 transistors has been replaced with ULN2803's
**broken link removed**
he gave its PCBlayout also but i don't know how we can use it for developing.
 
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