go_away

Author Topic: NO OUTPUT (VOLTAGE DROP) AT OUTPUT PIN  (Read 3038 times)

0 Members and 1 Guest are viewing this topic.

Offline katherinaTopic starter

  • Jr. Member
  • **
  • Posts: 29
  • Helpful? 0
NO OUTPUT (VOLTAGE DROP) AT OUTPUT PIN
« on: November 25, 2007, 08:42:14 PM »
hi... i'm currently working on climbing robot, rite now, i've built the hardware and the circuit is done too.
however, there is no voltage drop at the output pin, n i wonder why is dat so?
because we have detected that the input pin is working, with 5v supply... but, it does not produce any output...  where could be the problem be? ???
 tq

Offline ed1380

  • Supreme Robot
  • *****
  • Posts: 1,478
  • Helpful? 3
Re: NO OUTPUT (VOLTAGE DROP) AT OUTPUT PIN
« Reply #1 on: November 25, 2007, 08:47:36 PM »
I'm not really getting you.

if there is no output there could be a lot of different problems. it was programmed wrong, soldered wrong, etc.

could you be more specific
Problems making the $50 robot circuit board?
click here. http://www.societyofrobots.com/robotforum/index.php?topic=3292.msg25198#msg25198

Offline katherinaTopic starter

  • Jr. Member
  • **
  • Posts: 29
  • Helpful? 0
Re: NO OUTPUT (VOLTAGE DROP) AT OUTPUT PIN
« Reply #2 on: November 25, 2007, 08:50:44 PM »
i think the programming is correct....  there might be some electronics problem... but i dunno where the probkem could be...

Offline ed1380

  • Supreme Robot
  • *****
  • Posts: 1,478
  • Helpful? 3
Re: NO OUTPUT (VOLTAGE DROP) AT OUTPUT PIN
« Reply #3 on: November 25, 2007, 08:52:30 PM »
I'd take a multimeter and test the connections. also check that there are no shorts
Problems making the $50 robot circuit board?
click here. http://www.societyofrobots.com/robotforum/index.php?topic=3292.msg25198#msg25198

Offline katherinaTopic starter

  • Jr. Member
  • **
  • Posts: 29
  • Helpful? 0
Re: NO OUTPUT (VOLTAGE DROP) AT OUTPUT PIN
« Reply #4 on: November 25, 2007, 08:53:14 PM »
soldering?
 i have check the crystal connection, etc... can't find where it is wrong.

usually, where could be the problem if there are no outputs at the pin of PIC 16F877A?

becoz there is input(voltage of 5V) at the input pin of the chip.

Offline katherinaTopic starter

  • Jr. Member
  • **
  • Posts: 29
  • Helpful? 0
Re: NO OUTPUT (VOLTAGE DROP) AT OUTPUT PIN
« Reply #5 on: November 25, 2007, 08:54:35 PM »
ok... tq, may i know which part to test? at the PIC???

Offline ed1380

  • Supreme Robot
  • *****
  • Posts: 1,478
  • Helpful? 3
Re: NO OUTPUT (VOLTAGE DROP) AT OUTPUT PIN
« Reply #6 on: November 25, 2007, 08:56:35 PM »
I'd start at the output pin that doesnt work
Problems making the $50 robot circuit board?
click here. http://www.societyofrobots.com/robotforum/index.php?topic=3292.msg25198#msg25198

Offline paulstreats

  • Supreme Robot
  • *****
  • Posts: 1,381
  • Helpful? 21
Re: NO OUTPUT (VOLTAGE DROP) AT OUTPUT PIN
« Reply #7 on: November 25, 2007, 09:04:53 PM »
which pin is it? e.g rb1

Offline jsmoker

  • Full Member
  • ***
  • Posts: 118
  • Helpful? 2
Re: NO OUTPUT (VOLTAGE DROP) AT OUTPUT PIN
« Reply #8 on: November 26, 2007, 08:04:26 AM »
yeah, you need to give a lot more information.  What kind of micro controller are you using?  When you say there's 5V at on the input pin, do you mean the Vcc/Vdd?  is your ground connected properly (Vss).  Some micro controllers are finicky about writing to the "latch" instead of the "port".   Are you sure that the "port" operation is primary.  Often times certain leads can double as a UART or SPI, etc so you have to make sure it's set to be a digital output first.  If you have a schematic of your circuit that you help greatly, too.  Even an MS Paint drawing would help.

 


Get Your Ad Here