Partlist

Part Value Notes
R0 0 Ohm a.k.a jumper wire
R1-4, R21-24 1k Ohm, 0.25W, 5% R21-24 drive the LEDs and can be adjusted to other values
RP1-4 10k Ohm, 0.25W, 5%
R11-14 2.2k Ohm, 0.25W, 5% Other values will work, see explanations
D1-4 1N4148
T1-4 2N3904 Any equivalent will work (beware of pinout)
LED1-4 3mm LED
K1-4 IM03TS relays Other models from TE Connectivity / Axicom with the same footprint will work. See explanations
S1-4 SPST switch, 2 leads Specific P/N: B3WN6005 from Omron Electronic
SV1-4 2x3-pin DIL header
SV5 3-pin SIL header
SV6 5-pin SIL header I recommend using the angled version in this location, it fits nicely
RPI 2x13-pin DIL header