Hi Mike, Thank you very much for your suggestion, stepper runs a little bit slow now but with enough torque to move the capacitor. With the same wiring the stepper starts to run well but the transistors were very hot after a couple of seconds. In that way I have replaced the 2N3904 with a set of TIP102 darlington transistors. Now are working well and only a little bit hot. To control the stepper, and know in wich position is the capacitor I have placed a red led for the low value and a green led for the high value. There are 1.8 degree per step then there are 200 pulses per turn. So I need 25 turns to handle the capacitor. So I need to count 25 x 200 = 5000 pulses between the low and the high value of the capacitor. Now the next challenge is to know where is the capacitor when I turn oh the controller. I am saving the last position in the eeprom of the pic. In that way I have to display that value in a 4 x 7 segment display. It is possible using only pins of the RB and 2 pins from the RA ? Regards, Augusto ----- Original Message ----- From: "Mike Singer" To: Sent: Wednesday, July 16, 2003 12:33 AM Subject: Re: Stepper motor how to increase the torque > Wouter van Ooijen wrote: > > 2 you can increase the torque somewhat by using two-coil > > excitation (1100, 0110, 0011, 1001) instead of one-coil > > (1000, 0100, 0010, 0001). > > Perhaps 1000, 1100, 0100, 0110, 0010, 0011, 0001, 1001 > will work. > > Mike. > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.