SparkFun Polarized Connectors - Housing (4-Pin) Parts One of the nice features

One of the nice features of this board is a jumper on the back of the board that allows the board to be configured to either 3

Cheap fire-starting soldering irons often do not include a holding stand - this third hand can help prevent accidents and melt marks in the dining room table

to any other male header

a method of filtering this noise and pairing transmitter and receiver will be necessary

photo resistor

SparkFun Polarized Connectors - Housing (4-Pin) Parts One of the nice featuresPolarized connectors and headers for your perf board PCB projects. Use these connectors for power connections or any sensor general connection to prevent users from connecting the peripheral incorrectly or reversed. This is for the female housing. Be sure to order the mating header and crimp pins! Pins have standard . 1" spacing.