CSD_logic_probe bill of materials (BOM)
Step #1: Logic levels (HIGH, LOW) detection

https://digsys.upc.edu/csd/P01/Logic_Probe/Logic_probe.html

"C1","10uF", 25 V 
"CBP1","0.1uF",bypass capacitor 

"DR1", red LED 5.0mm, biased at 10 mA
"RR1","270 Ohm"

"DG1" green LED 5.0mm, biased at 10 mA
"RG1","270 Ohm"

"U1","LM339N", DIP-14, Quad analogue comparator
"U1",DIP-14 W7.62mm Integrated circuit socket

"HTIP1" , 01x01 long header 25 mm or 30 mm (probe tip), angle 90
"HV1","Conn_01x02", PinHeader 1x02, angle 90. 

"RL1,"1k"
"RL2,"1M"
"RL3","27k"
"RL4","6.8k"
"RL5","15k"
"RL6","5.6k"