RPD:
(can i use the mp3 SD card reader instead of WT588D-16p)
You can use it, but you'll likely get short gaps of silence when you switch sounds.
RPD:
is this all i need to make a soundboard for my lightsaber? i have2.4v 700ma 20mm XP-E red star led
(and royal blue star led... not sure for the voltage...)
28mm 8ohm 2w bass speaker
12v led momentary switch
18650 3.7v 2600mAh li-ion rechargeable battery
charger for the 18650 batteryand this is how i think i should connect everything....
am i doing something wrong?
Welcome.
You haven't wired anything incorrectly as far as I can tell, but you have too many components. If you have an ADXL335 accelerometer, you don't need the SW-18020P tilt sensor or the SW-200D. They serve the same purpose of detecting when the saber moves. You need to pick either the switches, or the accelerometer; it makes no sense to have both.
If you use the Universal Saber Library's ADXL335MotionManager class, you'll get fairly accurate motion sensing for free, but you'll likely have have to tune it. However, if you are a beginner and want your code to be simple, then the tilt/clash sensors are far easier to understand and code for.