Hello guys, I'm dealing with a problem I can't solve yet. I built a robot with Atmega328p, H bridge, couple motors, GLCD and PS2 keyboard. I attached schematic. Lcd shows keyboard outputs and some commands can control motors. The circuit was done on homemade pcb and it has some rust.
The robot is working 100% fine when connected to DC supply (7.5V regulated 2 A supply connected to LM7805). Also I connected it to another 4.5V regulated supply and works fine too, the motors run slower although.
But when I connect it to 6xAA batteries in series connected to LM7805 too, it works buggy. It communicates fine with keyboard, but when I turn on motors sometimes they don't work sometimes they do, lcd shows garbadge and sometimes Atmega328p reset itself. Batteries are rechargeable and they have energy (7.3 V in series).
I tried connecting capacitors for decoupling on both sides of 7805 both doesn't work. My guess is that it is a current problem, batteries cannot source enough current? Its kinda weird because 7.3V should be plenty of energy. Should I try with 9V battery?
Any hint will be helpful thanks in advance.
esq.PDF (188 KB)