One thing... Turn off BOD. It may reset the circuit if voltage drops too far. This can happen if the servo does hard work or just as it starts to move... KreAture ----- Original Message ----- From: "David VanHorn" To: Sent: Sunday, June 15, 2003 8:51 PM Subject: Re: [PIC]: Servo Pulse Problem > At 10:12 AM 6/15/2003 -0700, Joel Middleton wrote: > > >I found this schematic on the web and this is my exact > >circuit except the servo signal is connected to pin 3 > >on portb. Also I have all the unused pins connected to > >ground. Anyone see anything wrong with the circuit? > > A couple potential problems. (pun) > > Running a servo motor from your logic supply is a bad idea. > The motor has relatively large stall current demands, and produces a lot of noise. These both have the potential to reset or crash the micro. > > Try providing a separate supply for the servo motor, like four AA cells. > Keep the ground tied between the supplies though as that provides the reference for the pulse. > > Also, I've found that I need a series resistor of 100 ohms to 1k between the micro and the servo's pulse input. I've never investigated why, but I've had a few chips blown (Atmel AVRs) when I didn't have that series resistor. > > It's never a real good idea to take uP I/O pins directly into the real world. > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu