i uilt an arduino nano record and play robotic arm
but due to some reason my sevos move radomly ,without me teaching it
Without seeing your code, there is not much we can do to help. If your servos just jitter (constantly jerking back-and-forth), you probably have more than one servo node for a single servo and it is trying to hold several positions at the same time. You will need to rewrite your program to use a single node for each servo & control the position fed to it, or use something like gweimer/servo/servo-enable to only enable one node for each servo at at time. The down-side of the latter option is your servo will just free-wheel if all nodes for a servo are disabled, and your arm will probably collapse.