Well it would help to give more specific information on what you want the blinking to be like. Do you want them to all blink on and off at the same time? Random? some kind of sequenial pattern? When blinking, how much time on and then how much time off, milliseconds, seconds, random times?The answers will dictate the best solution, maybe a micro is not even required. However if as you say you do it already easily with an Arduino then the easy answer is to get a AVR chip with an installed Arduino bootloader, program it in your Arduino board and then transfer the chip to your new PCB board. The only extra support the chip needs is a few resistors, a 16mhz resonator a few caps and a voltage regulator.A normal 9 volt battery will not give you very long duration for blinking 32 LEDs. If you use 4 AA batteries in series you will get longer duration and save the need for a voltage regulator on your PCB.Lefty
8 x 10 Ohms resistors.