Arduino Based Robot tank servo motors reset arduino

[queennikki1972]

So I have this arduino based tank, that uses 12V Battery pack with power switch for the motors.

I can power the arduino from the same battery pack, however, when the motors stop, and change directions, there is a brief disruption in power, enough to keep resetting the arduino. Now I have plenty of components lying around and was wondering what I can do to fix this, maybe with capacitors or something?

Current solution is a separate 9v battery for the Arduino.. aka 2 separate power sources.

When I power my entire tank from only one power source using variable bench power supply at a constant current that seems to fix the issue. Maybe I just need a more powerful battery pack???

[sleemanj]

Put a big electrolytic capacitor directly on a VCC and Gnd pin of the arduino (or prefereably solder directly to a Vcc/Gnd pin on the ATMega itself).

[queennikki1972]

I also had to put a 5 volt regulator before the vcc using lm2596 module and it works now.

[MarkR42]

My guess is that the internal resistance of your supply is too high, or there are not enough smoothing capacitors on the MCU supply.

What kind of batteries are you using? Are they rated for the instantaneous current you're pulling?

[Mechatrommer]

just completed a mini project involving controlling servo motor from an mcu on a pcb. the power to servo is routed on the pcb and return current shared the gnd plane as the mcu, mcu has local decoupling cap, power input has one as well capacitor tank 10uF, the mcu keep resettting/halted each time the servo tries to move to a position, i put protection diode at servo power input, capacitor on various places, mcu still resetted, the only solution is to power servo from external power supply. the on board power source is china smps module 3A rated, i guesstimate the small servo only spiked to 1-2A when commanding to a position. i guess pcb traces is just not enough, or cant be shared with digital circuit, adding super big capacitor on the small board is not logical so i think i will need separate V+/GND traces running from power source point to power connector end that will power the servo/motor next time, ie bypassing, or not sharing the same line as the power that goes to the mcu. sort of star V+, star gnd config, or jumper wires. i remember i experienced this before but i guess i never learn.

[queennikki1972]

My guess is that the internal resistance of your supply is too high, or there are not enough smoothing capacitors on the MCU supply.

What kind of batteries are you using? Are they rated for the instantaneous current you're pulling?

It is just 2 servos, arduino and power switch and some running lights. Using regular AA batteries. The capacitor fixed it from resetting and it has to be run directly from the arduino vcc, however the max voltage on vcc is 5v max so i used the regulator to get the 5v for vcc and the capacitor inline with the vcc as well and now it works. I never ordered lithium or nicad batteries because it was meant to be something simple ..