Let's Make Robots!

why not obeying?

i have built the robot, it worked perfectly for the first day and obeyed all orders.

but on the second day when i tried it again, it didnt work...i changed the batteries and everything. even when i sent the orders the software confirmed that it was a succesful, but it still didnt move. only soft sounds(as if something is going on from inside) was herd.

please help!!! tommorow i have a presentation in school for this thing, how can i make it work...what should i do???

is it because of the batteries??? please help as fast as possible:(

i worked so hard on it:(

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I’m sorry to hear that your robot has stopped working. But you give us minimal information to work on here. Can give us some more information on your robot and some pictures?
The first thing I would try was just to feed power to the motors directly and see if they turn, if so, check all the connections again. If your using a H-bridge, maybe try pulling the input pins high to see if that works and so on.

Agree with Mr. Andersen. It just happened to me yesterday my bot not working because i have plug one of servo pin upside down. Slow down and pay attention on every little step to check up everything. It usually ends up a tiny little thing.

"noise from the inside" makes me think, if it is servo driven, that maybe some gears are damaged. The same goes for the bot if it is motivated by gear motors.

As Geir said, power the motors by themselves and then include more parts into their circuit as the previous parts prove they are functioning.

  1. try operating the robot with the wheels off the ground
  2. use a multimeter to test voltages around the circuit, is everything correct?
  3. report back with more details

the same thing happened to me when i used 3 stupid re-chargable batteries and 1 duracell. if you did or doing so, throw the re-chargables away, strange things happen. For your presentations, buy 4 normal batteries and use them. For long term usage, get some good re-chargables and <b>do</b> not use them with chargables

oddbot, when i meant by threw them away, i meant i did not use them any more on my robot. and my rechargables did work before i used the duracell and the rechargables were used on my start here robot.

thnak you guys for helping:)

yes i bought my kit from LMR... the first time i wanted to try my robot i inserted 3 MN1500; LR6;1.5 volts batteries and 1 with the same characteristics but a diffrent brand(because i didnt find andither 1 at thar moment). it worked perfectly.

the next day i tried 4 NEW normal batteries all the same brand (like the one i mentioned before). but it only obeyed my first order of moving the srvo 150 degree... then i tried 75 but didnt work , ony faint sound..and 150 again but nothing!?!?!

it went zombie:(. i opened the servo and presed reset but i saw that the servo wasnt moving even with power...( is it the servo or the microcontroller not sending the data)?? could it have burned??

if antother recuired info is needed im pleased to tell but i wanna know why it doesnt work.


If you don't have access to an oscilloscope to view the PWM signal you can test with an LED and see if it lights up dim (use a series resistor). Try separate power supplies for the servo and microcontroller if you aren't.