Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: irveltas on February 12, 2012, 09:59:03 AM
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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 ;)
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Does the programmer supply power to the board? If so how are you powering it without the programmer?
Joe
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im using 4xAA batteries for servos and 9v batterie for programmer as in the schematic.
5v at pin 2.
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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
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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.
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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 :)
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so i checked connections all is good, theres definitely power going to to programmer. multimeter shows 4.95.
could the programmer be faulty?
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What kind of programmer is it? What settings are you using? Can you show a screen shot of the setup?
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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?
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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
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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
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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).
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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
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got it working. thanks ppl.
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Hi,
What was the solution?
Others may run into similar problems and the solution may help them :)