PTC: Extend options, fix probing bugs (#18253)

Marlin/Configuration_adv.h

@@ -1662,6 +1662,37 @@
     // Enable additional compensation using hotend temperature
     // Note: this values cannot be calibrated automatically but have to be set manually
     //#define USE_TEMP_EXT_COMPENSATION
+
+    // Probe temperature calibration generates a table of values starting at PTC_SAMPLE_START
+    // (e.g. 30), in steps of PTC_SAMPLE_RES (e.g. 5) with PTC_SAMPLE_COUNT (e.g. 10) samples.
+
+    // #define PTC_SAMPLE_START  30.0f
+    // #define PTC_SAMPLE_RES    5.0f
+    // #define PTC_SAMPLE_COUNT  10U
+
+    // Bed temperature calibration builds a similar table.
+
+    // #define BTC_SAMPLE_START  60.0f
+    // #define BTC_SAMPLE_RES    5.0f
+    // #define BTC_SAMPLE_COUNT  10U
+
+    // The temperature the probe should be at while taking measurements during bed temperature
+    // calibration.
+    // #define BTC_PROBE_TEMP 30.0f
+
+    // Height above Z=0.0f to raise the nozzle. Lowering this can help the probe to heat faster.
+    // Note: the Z=0.0f offset is determined by the probe offset which can be set using M851.
+    // #define PTC_PROBE_HEATING_OFFSET 0.5f
+
+    // Height to raise the Z-probe between heating and taking the next measurement. Some probes
+    // may fail to untrigger if they have been triggered for a long time, which can be solved by
+    // increasing the height the probe is raised to.
+    // #define PTC_PROBE_RAISE 15U
+
+    // If the probe is outside of the defined range, use linear extrapolation using the closest 
+    // point and the PTC_LINEAR_EXTRAPOLATION'th next point. E.g. if set to 4 it will use data[0]
+    // and data[4] to perform linear extrapolation for values below PTC_SAMPLE_START.
+    // #define PTC_LINEAR_EXTRAPOLATION 4
   #endif
 #endif