Author Topic: another problem with 50$ robot  (Read 950 times)

0 Members and 1 Guest are viewing this topic.

Offline irveltasTopic starter

  • Jr. Member
  • **
  • Posts: 10
  • Helpful? 0
another problem with 50$ robot
« on: February 12, 2012, 09:59:03 AM »
 servos not rotating when my programmer isnt connected to pc through usb.
 i got my microcontroler done, servos modified, programmed but if i disconnect programmer green lights goes out and servos stop moving. what am i missing? probably something stupid as usual so pls dont laugh  ;)

Offline joe61

  • Supreme Robot
  • *****
  • Posts: 417
  • Helpful? 16
Re: another problem with 50$ robot
« Reply #1 on: February 12, 2012, 10:42:11 AM »
Does the programmer supply power to the board? If so how are you powering it without the programmer?

Joe

Offline irveltasTopic starter

  • Jr. Member
  • **
  • Posts: 10
  • Helpful? 0
Re: another problem with 50$ robot
« Reply #2 on: February 12, 2012, 10:46:34 AM »
im using 4xAA batteries for servos and 9v batterie for programmer as in the schematic.
5v  at pin 2.
« Last Edit: February 12, 2012, 11:04:15 AM by irveltas »

Offline joe61

  • Supreme Robot
  • *****
  • Posts: 417
  • Helpful? 16
Re: another problem with 50$ robot
« Reply #3 on: February 12, 2012, 12:36:53 PM »
Well assuming the connections are all well soldered, the only thing I could think of is that the battery isn't charged up enough.

Joe

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: another problem with 50$ robot
« Reply #4 on: February 12, 2012, 12:47:25 PM »
Hi,

Perhaps some of the pins controlled by the programmer need pull-up (or -down) resistors to place them in a known and stable condition when the programmer is removed.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline irveltasTopic starter

  • Jr. Member
  • **
  • Posts: 10
  • Helpful? 0
Re: another problem with 50$ robot
« Reply #5 on: February 12, 2012, 12:50:21 PM »
its a new batteries. ill recheck the connections anyway. ty joe


Perhaps some of the pins controlled by the programmer need pull-up (or -down) resistors to place them in a known and stable condition when the programmer is removed.
pls explain pull-up or down, im a total newbie :)

Offline irveltasTopic starter

  • Jr. Member
  • **
  • Posts: 10
  • Helpful? 0
Re: another problem with 50$ robot
« Reply #6 on: February 12, 2012, 01:22:59 PM »
so i checked connections all is good, theres definitely power going to to programmer. multimeter shows 4.95.
could the programmer be faulty?

Offline joe61

  • Supreme Robot
  • *****
  • Posts: 417
  • Helpful? 16
Re: another problem with 50$ robot
« Reply #7 on: February 12, 2012, 01:57:46 PM »
What kind of programmer is it? What settings are you using? Can you show a screen shot of the setup?

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: another problem with 50$ robot
« Reply #8 on: February 12, 2012, 02:34:00 PM »
pls explain pull-up or down, im a total newbie :)
A resistor that connects to either Vdd or Vss  (which Atmel erroneously call Vcc and Vee IIRC).
The purpose is to avoid floating inputs, as that could (and probably would) keep your program from running.

The pins that go to the programmer... Are any of them left unconnected when the programmer is removed?
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline joe61

  • Supreme Robot
  • *****
  • Posts: 417
  • Helpful? 16
Re: another problem with 50$ robot
« Reply #9 on: February 12, 2012, 03:35:06 PM »
I don't think it's pullups/pulldowns According to the data sheet it's just a SPI bus with some extra stuff to hold reset low. They don't show any pullup/pulldown resistors in the pinout.

I'd suggest rechecking the connections too.

Joe
« Last Edit: February 12, 2012, 03:37:12 PM by joe61 »

Offline joe61

  • Supreme Robot
  • *****
  • Posts: 417
  • Helpful? 16
Re: another problem with 50$ robot
« Reply #10 on: February 12, 2012, 03:51:41 PM »
so i checked connections all is good, theres definitely power going to to programmer. multimeter shows 4.95.
could the programmer be faulty?

Where are you measuring at?

I looked at the wiring diagram you linked to earlier, and noticed that AVcc is connected to the positive pin of the programmer header. AVcc should be connected to Vcc, not as a power source for the programmer (it's the power source for port A and the AD converter) . It looks like it's being used as just another voltage source. I'm not really sure if that can wind up doing what you're observing, but I suspect it will throw off AD conversions if nothing else.

I'm still fighting a cold so maybe I'm not seeing something, but that wiring setup doesn't look right to me (at least not now).

Joe

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: another problem with 50$ robot
« Reply #11 on: February 12, 2012, 04:17:52 PM »
Hi,

I don't think it's pullups/pulldowns According to the data sheet it's just a SPI bus with some extra stuff to hold reset low. They don't show any pullup/pulldown resistors in the pinout.
Well, it won't run without the /Reset pulled high, and I wouldn't be surprised if that was missing, judging from it working with the interface connected (which make it very unlikely that the error should be anywhere else than in the interface part).
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline joe61

  • Supreme Robot
  • *****
  • Posts: 417
  • Helpful? 16
Re: another problem with 50$ robot
« Reply #12 on: February 12, 2012, 04:57:23 PM »
Oh, sorry I thought you were talking about the other lines. The reset line has an internal pullup on by default. I think it can be turned off by programming a fuse, if so that might be an issue.

Joe

Offline irveltasTopic starter

  • Jr. Member
  • **
  • Posts: 10
  • Helpful? 0
Re: another problem with 50$ robot
« Reply #13 on: February 13, 2012, 04:35:05 PM »
got it working. thanks ppl.

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: another problem with 50$ robot
« Reply #14 on: February 13, 2012, 05:26:20 PM »
Hi,

What was the solution?
Others may run into similar problems and the solution may help them :)
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

 


Get Your Ad Here

data_list