Post by thread:[PIC]: Very basic hookup help needed

I'm able to get a PIC16F877 programmed and verified, but I'm having trouble getting it running on a breadboard where it should blink a single LED every couple of seconds. (1) Should both Vdd and Vss pins be connected? (2) When in-circuit, I have 3 LEDs going. One to show if power is on, another on my output pin, and a third on a second pin which I set to low. When power is applied, all three LEDs blink on and off, maybe once a second for as long as power is applied. Many thanks, Benjamin __________________________________________________ Do You Yahoo!? Get personalized email addresses from Yahoo! Mail - only $35 a year! http://personal.mail.yahoo.com/ -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email spam_OUTlistservTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body

> > I'm able to get a PIC16F877 programmed and verified, > but I'm having trouble getting it running on a > breadboard where it should blink a single LED every > couple of seconds. > > (1) Should both Vdd and Vss pins be connected? Absolutely and always. > (2) When in-circuit, I have 3 LEDs going. One to > show if power is on, another on my output pin, and a > third on a second pin which I set to low. When power > is applied, all three LEDs blink on and off, maybe > once a second for as long as power is applied. If the power LED is simply connected between Vdd and Vss with a resistor and it's blinking, then that would point to a power supply problem. BAJ -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email .....listservKILLspam@spam@mitvma.mit.edu with SET PICList DIGEST in the body

Hook up both vdd's and vss's. Put a small cap across them. Sometimes a LED sucks up enough power (depending on how you're powering your chip) that a reset happens whenever you turn your led on. The cap should help. -Adam Benjamin Wood wrote: {Quote hidden}> > I'm able to get a PIC16F877 programmed and verified, > but I'm having trouble getting it running on a > breadboard where it should blink a single LED every > couple of seconds. > > (1) Should both Vdd and Vss pins be connected? > (2) When in-circuit, I have 3 LEDs going. One to > show if power is on, another on my output pin, and a > third on a second pin which I set to low. When power > is applied, all three LEDs blink on and off, maybe > once a second for as long as power is applied. > > Many thanks, > Benjamin > > __________________________________________________ > Do You Yahoo!? > Get personalized email addresses from Yahoo! Mail - only $35 > a year! http://personal.mail.yahoo.com/ > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email listservKILLspammitvma.mit.edu with SET PICList DIGEST in the body -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email .....listservKILLspam.....mitvma.mit.edu with SET PICList DIGEST in the body

At 06:15 AM 2/9/01 -0800, you wrote: >I'm able to get a PIC16F877 programmed and verified, >but I'm having trouble getting it running on a >breadboard where it should blink a single LED every >couple of seconds. > >(1) Should both Vdd and Vss pins be connected? >(2) When in-circuit, I have 3 LEDs going. One to >show if power is on, another on my output pin, and a >third on a second pin which I set to low. When power >is applied, all three LEDs blink on and off, maybe >once a second for as long as power is applied. > You do have resistors in series with each of the LEDs, don't you? At least 500-1000 ohms in value? -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email EraseMElistservspam_OUTTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body