[student1616]

hello guys,
iam not exactly new to this forum.but its my first post.
this forum helps me in understanding many things.thanks guys.
iam searching for a good and simple stepper motor driver.i already visited pminmo's site and found some good info but unable to get some components in his design.so while searching for another one on net i found below one.has any one done such ckt before?
http://uvasux.googlepages.com/steppermotorcontroller
but i did't understand some points in it.
1.it doest not use PIC then whats the purpose of make file and .C,.H files.
2.iam planning to use steppers from printers.is it ok?
3.can i use softwares like turboCNC,Mach-2/3 with it.

i already mailed author regarding it(did't get reply yet).mean while i want to hear from u expert guys.
thanks
student

[kreutz]

hello guys,
iam not exactly new to this forum.but its my first post.
this forum helps me in understanding many things.thanks guys.
iam searching for a good and simple stepper motor driver.i already visited pminmo's site and found some good info but unable to get some components in his design.so while searching for another one on net i found below one.has any one done such ckt before?
http://uvasux.googlepages.com/steppermotorcontroller
but i did't understand some points in it.
1.it doest not use PIC then whats the purpose of make file and .C,.H files.
2.iam planning to use steppers from printers.is it ok?
3.can i use softwares like turboCNC,Mach-2/3 with it.

i already mailed author regarding it(did't get reply yet).mean while i want to hear from u expert guys.
thanks
student

It has been designed for very small motors and does not have current control or limit.

The files are for the PC software to control it.

[higgrobot]

Printer steppers hey? you don't say what size or what you plan to use them for?
I looked at http://pminmo.com/3axis/3axis.htm and all the parts for that are available almost everywhere. The mosfets could be substituted with any garden variety N-Channel TO220BV package.

[scratch_6057]

On the TurboCNC page, click the HARDWARE link,
Cllik the picture of the chip, at the bottom of the third
page is a space for another picture click that and you'll
get the schematic

Search around under the HARDWAREarea (READ THE TEXT)
and you'll find all you need including source for a PIC16F84
and PIC12C508

[student1616]

1.my idea is to built XYZ small engraver.so i think printer motors will do the job.
at first i planned to biult that 3-axis board(top design in above page) but iam unable to find mosfet IRLZ44 and someone said IRFZ44 is not a good replacement for that(as its not sure and they r costly so i dropped it).and one more issue with that board is pcb layout.traces r so close toner transfer did't work.(the layout is in max copper mode righ.is there any other layout design for this board)
2.thanks i understood that those files r control software for the board
3.@scratch_6057
thanks for the link.i think we can run 2 steppers with one PIC.then do i need another PIC chip to run 3rd axis? and is it necessary to heatsink 2N2222's

thanks for guiding me guys
student

[scratch_6057]

3.@scratch_6057
thanks for the link.i think we can run 2 steppers with one PIC.then do i need another PIC chip to run 3rd axis? and is it necessary to heatsink 2N2222's

thanks for guiding me guys
student

Student,

Yes you can run 2 steppers from the first PIC (PIC16F84) and
add a second one for the third (and optional fourth) stepper output
or use the 12C508A chip (source code linked on the TurboCNC site)
for a single third output.

As for heat sinking the xx2222x Transistors, that’s going to depend on the
current requirements of your steppers, and it may be a little hard to do.
In MY world the 2222 is most commonly available in a TO-92 (?) plastic
package and a tiny metal TO-18 (?) "CAN" not exactly the simplest
packages to heat sink. In any event, I think the TO-18 can is rated
for 800mA and the plastic package is 500mA.

I started to change the provided design a little by substituting TIP-120
Darlington Transistors in a TO-220 package. Those are rated for 5A
and easy to heat sink. Here is the link for the thread I started on doing that
http://www.cnczone.com/forums/showthread.php?t=30996
If you go this route, you might use the 2222s to switch on the base
of the TIP-120, I'm not sure that the PIC alone can provide enough
"UMPH" to fully turn on the TIP-120 fast enough.

Another option you may want to consider looking at depending on your
requirements is the Linistepper mentioned in this site
(site search for "Linistepper) and others.

[scratch_6057]

Just a quick search on Google's 'Froogle' (put IRLZ44 in search box.
then select 'MORE" then 'Froogle') turns up some of these for a $1.75
(+ $1.50 Flat Rate shipping) on EBay, NOT a bad price considering the specs.

(If you think that price is high try buying surface mount H-Bridge
FET packages in small quantity i.e. 'ZXMHC3A01T8' )

They are being sold by 'PHAnderson Electronics' who I believe is a
Professor at a University in Maryland

http://cgi.ebay.com/IRLZ44-N-Channel...QQcmdZViewItem

I have never bought anything from him but I know a couple
of people who have and from I understand he is a reputable
person.

[student1616]

thanks for the reply.
u said i can use another PIC to control Z axis.so if i burn same code and connect it to Z motor will it work? or no i need any modification in the program.

and iam not good at PIC's.so i have some general doubts.

1.i got 2 PIC16LF84A's can i uses them? (not PIC16F84)
2.is this chip consist of internal Clock?
3.have u built this whole setup before? then how did it worked.

i made a small drawing abt the connection required for a small CNC.pls have a look and let me know if it need any modification.

thanks

[kreutz]

Looking at your attached schematic, it is designed for a very small motor, about 300 mA, low inductance, about 5-12 volt rated motor. It also, does not have a current limiting feature, so you will have to use your little motor at its rated voltage, otherwise you could damage it or the output transistors. Using darlingtons for switching is not recommendable, because of the higher Vce in saturation. Stay with a (logic) mosfet for higher efficiency.

[student1616]

thanks for fast reply.
so i use TIP120 instead of 2N2222 will it take some more load.
wile searching for PIC based controller i just found this
http://www.imagesco.com/images/picstepper/fig04.gif
this circuit uses 4050 and TIP120.
what is ur opinion abt it.

and i forgot to draw.but i'll connect a high watt resisitor between motor common and +12v supply to control the current.

[kreutz]

Look at the highlighted text on the attached data-sheet.

What are your motor's specs? I can't see any step-direction or any other control input on the schematic shown in that link.

Your PIC needs to provide at least 12 mA (output high) for 3A collector current or use a pull-up resistor and make sure your PIC can sink more than that current, otherwise you will need a buffer.

There are other simple, logic gates based, translator's configurations that don't include any programming. What step mode are you planning to use?

[kreutz]

Take a look at this site: http://pminmo.com/ Phil has compiled a lot of good simple designs on that site. There is also a lot of good information around in the forum. You can always adapt those designs to your own necessities.

[student1616]

well iam using motors from printers.they are small and cheap,so i exactly donno the spec.and details of them.
yes that picture i posted did't have any parallel port connections.its just for running the motor using push buttons.but i was looking at the output of the circuit.i mean output to coils through 4050 and tip120.can we just replace that part in our circuit to handle more current?
and can i use PIC16LF84A instead of PIC16LF84

[kreutz]

The A version is simply a later version. On different PIC models, the A means different things. On the 84, the A has a shorter flash lifetime in trade for a longer EEPROM life which was very short on the non-A version. On most of the later PICs, the A means newer flash technology, which is usually faster to program, and significantly cheaper.

[kreutz]

well iam using motors from printers.they are small and cheap,so i exactly donno the spec.and details of them.

My friend, you need the specs in order to drive them. What voltage and current are you going to use if you don't know them? remember that your circuit does not limit current. You need to find out those specs, look at the model numbers and manufacturer's name on the labels.

[kreutz]

Ah, forgot to tell you, make sure the programmer you are using support the PIC16LF84A, they might have a different programming algorithm from the PIC16LF84.

[kreutz]

The A version is also capable of driving the TIP120, look at the specs taken from the data-sheet: (highlighted on the attached file too)

Peripheral Features:
• 13 I/O pins with individual direction control
• High current sink/source for direct LED drive
- 25 mA sink max. per pin
- 25 mA source max. per pin

[student1616]

thanks kreutz for reminding me abt current limit resistor.i'll try to find out motor details(or by trial and error i have to find the resistor value)
so i can use A version(and the given code) with supporting programmer.i'll do that.
http://img179.imageshack.us/img179/444/stepdrivepz9.gif

[kreutz]

You cannot use only one resistor if you are planning to use full-step with 2 phases on or half step, it is OK for full-Step with only one phase on at the time. Otherwise when you have both phases on the voltage drop will be too much.

In that case, you will need to add 4 resistors , each of them located between the coil and the respective collector.

You don't need the buffer stage between the PIC and the darlingtons. Just calculate the base resistors to make them saturate.

[student1616]

i got it.no need of 4050 between pic and TIP120 right.
that previous design uses 1K resistor between 2N2222 and pic.

the below data i found on net to calculate resistance value

Anytime a power supply for the stepper motor is used that is greater than the rated voltage of the motor, current limiting
resistors are required. This board does not contain room for current limiting resistors as they can be quite large sometimes.
The coil resistance of the motor can be computed by dividing the rated voltage by the rated current. For example a motor
rated at 5.2 volts @ 1.6 A (5.2/1.6) has a coil resistance of 3.25 ohms. To compute the size of the current limiting resistor
subtract the motor voltage rating from the power supply voltage and divide it by the current rating. For example using a 12v
power supply with the above motor (12-5.2/1.6), you would need a 4.25 ohm resistor. The wattage rating of that resistor is
the current squared times the resistor value (1.6 * 1.6 *4.25) or in this case 10.88 watts minimum. Power resistors come in
standard wattage ratings or 1, 5, 10, 25, 50 watts.