Let's Make Robots!

adruino and adafruit motor shield problems

anyone have an idea why my motor are jerking at the same rate as my ping is fireing?  i have the ping on pin 9 so i can just plug it inot the motor shields servo port ( it is just power and pin 9) is this the problem? I know i have a lot of power 8 AA nimh at 2000 mah. my meter says the voltage is over 10 volts. they could be bad batteries. but why the jerking of the motors. it occasionally works right. ( i know i am ranting) any ideas?


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appears it is too high of voltage, but why ?


 I always recommend separate batteries for the motors and the processor. That usually helps...

/ vzz-clck-"Maneuver"

how do you have your ping hooked up? do you have signal hooked up to pin 9 and the 5+ and ground hooked upto the arduino

are you powering the sheild by a seperate power supply or just using the arduino ot power the motors

or take a picture of the wiring, might be helpful.......

are the batteries full charged?

why are you connecting the ping to pin 9? you can use the analog pins..

how do i use the analog pin? i dont know what the pin number is for it.
I had the same problem you had described. I solved it by using two different power sources. I have a 9v battery to run the arduino and 4 AA's to run the shield. Unfortunately I burned an L293 chip in the process of trying to figure it out. You can also go to her website, I think it's Ladyada's teaparty or something like that. She's quick to respond about problems with her product, she is the one that helped me figure it out.

the site is http://www.ladyada.net/make/mshield/

it has alot of good info and trouble shooting on that site

ok maybe i was not detailed enough, thank you for your replies.

arduino is running off a 9v

shield is off a separate 8 AA pack 2000 Mah

the ping on pin nine would be off the 9v power from the arduino same as the servo would be.

The motors run oof the AA pack just like the ladyada's web stire described. i can't figure out why it work at the lower voltage of 4 AA but not the 8.


The Ping needs a 5 volt supply, not 9 volts. Overvolting can burn things up. The RC servos are also rated for 4.8 or 6 volt operation, not 9 volts.  It appears that you have 2 packs that have 8 AA batteries each, is that the case? A picture of your set-up would really help. Lady Ada's motor shield use page has the servos connected to the motor shield, not sure where you have the sonar attached. If the servos are on the motor shield, then they appear to be getting 5 volts. Some sonars when "pinging" can cause a quick current draw that might be responsible for jitter, so a big cap located close to the sonar might help smooth any quick drain. Perhaps something like a 470 uF or larger would work.

i have the ping on the servo 2 on the motor shield so it is getting a regulated 5v not 9. i am closing this thread. taking it elsewhere.