Orangutan SVP 1284 resets when there is servo load

Hello,

I am trying to use Orangutan SVP to controll a robotic arm. Everything is going fine untill the robotic arm grab something heavy. In that moment, Orangutan immediatelly resets. For powering servos, i use the onboard Vadj regulator adjusted to 6 V (according to datasheet of servos). I messured the current being drawn by the four servos- I added an ampermeter between Vadj pin and the pin which is connected to V pin of all four servosv and it is always under 2A, but the reset occurs when the current is high (1,8-1,9A). The voltage on these pins is fine. Can this be caused by noise generated by servos? Is it possible to add a capacitor to filter the noise and prevent resets? If yes, what capacity should I use, and where should I put it? Are there any other possible reasons of reset?

Sincerely, Jan

PS: I am trying to controll this arm with original servos: lynxmotion.com/p-684-al5b-ar … s-kit.aspx.

Hello.

Servos like the ones that arm has can draw well over an amp while straining, and it is very likely that you are just trying to get too much current out of the SVP’s VADJ regulator. I suggest you power your servos from an external battery, or split them up so that some are powered from VADJ and some from VCC.

Note that while you might only be measuring 2 A of current draw, the actual current draw could be regularly spiking much higher (e.g. maybe one servo is trying to draw 5 A 20% of the time). The only way to see what’s going on clearly would be with a current probe on an oscilloscope. You might find this post on servos from our president’s blog especially relevant:

pololu.com/blog/17/servo-con … -in-detail

- Ben