grep -r 'IR_SENSOR' Prusa-Firmware-MK3S/
Prusa-Firmware-MK3S//Firmware/pins_Einsy_1_0.h:#define IR_SENSOR_PIN 62 //idler sensor @PK0 (digital pin 62/A8)
Prusa-Firmware-MK3S//Firmware/variants/1_75mm_MK25S-RAMBo10a-E3Dv6full.h:#define IR_SENSOR
Prusa-Firmware-MK3S//Firmware/variants/1_75mm_MK3S-EINSy10a-E3Dv6full.h:#define IR_SENSOR
Prusa-Firmware-MK3S//Firmware/variants/1_75mm_MK25S-RAMBo13a-E3Dv6full.h:#define IR_SENSOR
Prusa-Firmware-MK3S//Firmware/fsensor.cpp:		if (digitalRead(IR_SENSOR_PIN) == 1) {
Prusa-Firmware-MK3S//Firmware/fsensor.cpp:		if ((digitalRead(IR_SENSOR_PIN) == 1) && CHECK_FSENSOR && fsensor_enabled && ir_sensor_detected)
Prusa-Firmware-MK3S//Firmware/pins_Rambo_1_0.h:#define IR_SENSOR_PIN 20 //idler sensor 
Prusa-Firmware-MK3S//Firmware/pins_Rambo_1_3.h:#define IR_SENSOR_PIN 20 //idler sensor
Prusa-Firmware-MK3S//Firmware/mmu.cpp:	PIN_INP(IR_SENSOR_PIN); //input mode
Prusa-Firmware-MK3S//Firmware/mmu.cpp:	PIN_SET(IR_SENSOR_PIN); //pullup
Prusa-Firmware-MK3S//Firmware/mmu.cpp://if IR_SENSOR defined, always returns true
Prusa-Firmware-MK3S//Firmware/mmu.cpp:#ifdef IR_SENSOR
Prusa-Firmware-MK3S//Firmware/mmu.cpp:#else //IR_SENSOR
Prusa-Firmware-MK3S//Firmware/mmu.cpp:	//if IR_SENSOR_PIN input is low and pat9125sensor is not present we detected idler sensor
Prusa-Firmware-MK3S//Firmware/mmu.cpp:	if ((PIN_GET(IR_SENSOR_PIN) == 0) 
Prusa-Firmware-MK3S//Firmware/mmu.cpp:#endif //IR_SENSOR
Prusa-Firmware-MK3S//Firmware/mmu.cpp:#ifndef IR_SENSOR
Prusa-Firmware-MK3S//Firmware/mmu.cpp:#endif //IR_SENSOR not defined
Prusa-Firmware-MK3S//Firmware/mmu.cpp:            if (PIN_GET(IR_SENSOR_PIN) == 0 && mmu_loading_flag)
Prusa-Firmware-MK3S//Firmware/mmu.cpp:				if (PIN_GET(IR_SENSOR_PIN) == 0) move = MMU_NO_MOVE;
Prusa-Firmware-MK3S//Firmware/mmu.cpp:				if (PIN_GET(IR_SENSOR_PIN) == 0) //filament is still detected by idler sensor, printer helps with unlading 
Prusa-Firmware-MK3S//Firmware/mmu.cpp:				if (PIN_GET(IR_SENSOR_PIN) == 0) //filament detected by idler sensor, we must unload first 
Prusa-Firmware-MK3S//Firmware/mmu.cpp:			if (PIN_GET(IR_SENSOR_PIN) == 0) return;
Prusa-Firmware-MK3S//Firmware/mmu.cpp:		if (PIN_GET(IR_SENSOR_PIN) != 0) {
Prusa-Firmware-MK3S//Firmware/ultralcd.cpp:		idler_state = !PIN_GET(IR_SENSOR_PIN);
Prusa-Firmware-MK3S//Firmware/ultralcd.cpp://!    and sample IR_SENSOR_PIN.
Prusa-Firmware-MK3S//Firmware/ultralcd.cpp:            if (PIN_GET(IR_SENSOR_PIN) == 0) return false;
Prusa-Firmware-MK3S//Firmware/Marlin_main.cpp:#ifdef IR_SENSOR
Prusa-Firmware-MK3S//Firmware/Marlin_main.cpp:#endif //IR_SENSOR