VCC VCC VCC U10 100R U9 2 2 100NF 1 RES U13 4 RE TC RC TA 3 2 + 3 1 IN OUT 1 AO 1 U3 1K U12 AO 2 2 4 IN U1 VCC 10K U6 8 R R TCRT5000 R U5 3 20K VCC 1 U7 R - 100NF VCC VCC VCC 3 GND U8 CON3_ET