U4 is the CD74HC42, which is a BCD-to-decimal decoder. This device takes the BCD number and activates one of 10 outputs accordingly (active low). C4 is a bypass capacitor that is placed near the IC to help mitigate power supply noise and provide current quickly to the device when needed.

U5–U7 are each a TMUX1574, which are 2:1 (SPDT) 4-channel, powered-off protection switches that are used to split each output from U4 into two outputs. The direction line from U2 is used as an input to the switches to determine which of the two outputs should be active. C5–C7 are bypass capacitors that are placed near the ICs to help mitigate power supply noise and provide current quickly to the devices when needed.

Each output pair from U5–U7 connects to an individual RGB LED (in D1–D10), with one output going into the blue LED and the other output into the green LED. Because the switches U5–U7 are toggled from the direction line, the LEDs will show green or blue based on the direction the magnet is rotating. The specific LED lit up will be based on the BCD number 0–9 from the up/down counter (U3). R7–R27 are used as current-limiting resistors for the LEDs.