diff --git a/Marlin/src/lcd/tft_io/touch_calibration.cpp b/Marlin/src/lcd/tft_io/touch_calibration.cpp
new file mode 100644
index 0000000000..aaac16c466
--- /dev/null
+++ b/Marlin/src/lcd/tft_io/touch_calibration.cpp
@@ -0,0 +1,84 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2019 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ *
+ */
+
+#include "touch_calibration.h"
+
+#if ENABLED(TOUCH_SCREEN_CALIBRATION)
+
+#include "../../inc/MarlinConfig.h"
+
+TouchCalibration touch_calibration;
+
+touch_calibration_t TouchCalibration::calibration;
+calibrationState TouchCalibration::calibration_state = CALIBRATION_NONE;
+touch_calibration_point_t TouchCalibration::calibration_points[4];
+
+bool TouchCalibration::handleTouch(uint16_t x, uint16_t y) {
+ static millis_t next_button_update_ms = 0;
+ const millis_t now = millis();
+ if (PENDING(now, next_button_update_ms)) return false;
+ next_button_update_ms = now + BUTTON_DELAY_MENU;
+
+ if (calibration_state < CALIBRATION_SUCCESS) {
+ calibration_points[calibration_state].raw_x = x;
+ calibration_points[calibration_state].raw_y = y;
+ }
+
+ switch (calibration_state) {
+ case CALIBRATION_TOP_LEFT: calibration_state = CALIBRATION_BOTTOM_LEFT; break;
+ case CALIBRATION_BOTTOM_LEFT: calibration_state = CALIBRATION_TOP_RIGHT; break;
+ case CALIBRATION_TOP_RIGHT: calibration_state = CALIBRATION_BOTTOM_RIGHT; break;
+ case CALIBRATION_BOTTOM_RIGHT:
+ if (validate_precision_x(0, 1) && validate_precision_x(2, 3) && validate_precision_y(0, 2) && validate_precision_y(1, 3)) {
+ calibration_state = CALIBRATION_SUCCESS;
+ calibration.x = ((calibration_points[2].x - calibration_points[0].x) << 17) / (calibration_points[3].raw_x + calibration_points[2].raw_x - calibration_points[1].raw_x - calibration_points[0].raw_x);
+ calibration.y = ((calibration_points[1].y - calibration_points[0].y) << 17) / (calibration_points[3].raw_y - calibration_points[2].raw_y + calibration_points[1].raw_y - calibration_points[0].raw_y);
+ calibration.offset_x = calibration_points[0].x - int16_t(((calibration_points[0].raw_x + calibration_points[1].raw_x) * calibration.x) >> 17);
+ calibration.offset_y = calibration_points[0].y - int16_t(((calibration_points[0].raw_y + calibration_points[2].raw_y) * calibration.y) >> 17);
+ calibration.orientation = TOUCH_LANDSCAPE;
+ }
+ else if (validate_precision_y(0, 1) && validate_precision_y(2, 3) && validate_precision_x(0, 2) && validate_precision_x(1, 3)) {
+ calibration_state = CALIBRATION_SUCCESS;
+ calibration.x = ((calibration_points[2].x - calibration_points[0].x) << 17) / (calibration_points[3].raw_y + calibration_points[2].raw_y - calibration_points[1].raw_y - calibration_points[0].raw_y);
+ calibration.y = ((calibration_points[1].y - calibration_points[0].y) << 17) / (calibration_points[3].raw_x - calibration_points[2].raw_x + calibration_points[1].raw_x - calibration_points[0].raw_x);
+ calibration.offset_x = calibration_points[0].x - int16_t(((calibration_points[0].raw_y + calibration_points[1].raw_y) * calibration.x) >> 17);
+ calibration.offset_y = calibration_points[0].y - int16_t(((calibration_points[0].raw_x + calibration_points[2].raw_x) * calibration.y) >> 17);
+ calibration.orientation = TOUCH_PORTRAIT;
+ }
+ else {
+ calibration_state = CALIBRATION_FAIL;
+ calibration_reset();
+ }
+
+ if (calibration_state == CALIBRATION_SUCCESS) {
+ SERIAL_ECHOLNPGM("Touch screen calibration completed");
+ SERIAL_ECHOLNPAIR("TOUCH_CALIBRATION_X ", calibration.x);
+ SERIAL_ECHOLNPAIR("TOUCH_CALIBRATION_Y ", calibration.y);
+ SERIAL_ECHOLNPAIR("TOUCH_OFFSET_X ", calibration.offset_x);
+ SERIAL_ECHOLNPAIR("TOUCH_OFFSET_Y ", calibration.offset_y);
+ SERIAL_ECHOPGM("TOUCH_ORIENTATION "); if (calibration.orientation == TOUCH_LANDSCAPE) SERIAL_ECHOLNPGM("TOUCH_LANDSCAPE"); else SERIAL_ECHOLNPGM("TOUCH_PORTRAIT");
+ }
+ break;
+ default: break;
+ }
+
+ return true;
+}
+
+#endif // ENABLED(TOUCH_SCREEN_CALIBRATION)
diff --git a/Marlin/src/lcd/tft_io/touch_calibration.h b/Marlin/src/lcd/tft_io/touch_calibration.h
new file mode 100644
index 0000000000..472966cd2e
--- /dev/null
+++ b/Marlin/src/lcd/tft_io/touch_calibration.h
@@ -0,0 +1,111 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2019 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ *
+ */
+#pragma once
+
+#include "../../inc/MarlinConfigPre.h"
+
+#if ENABLED(TOUCH_SCREEN_CALIBRATION)
+
+#ifndef TOUCH_SCREEN_CALIBRATION_PRECISION
+ #define TOUCH_SCREEN_CALIBRATION_PRECISION 80
+#endif
+
+#ifndef TOUCH_SCREEN_HOLD_TO_CALIBRATE_MS
+ #define TOUCH_SCREEN_HOLD_TO_CALIBRATE_MS 2500
+#endif
+
+#define TOUCH_ORIENTATION_NONE 0
+#define TOUCH_LANDSCAPE 1
+#define TOUCH_PORTRAIT 2
+
+#if !(defined(TOUCH_CALIBRATION_X) || defined(TOUCH_CALIBRATION_Y) || defined(TOUCH_OFFSET_X) || defined(TOUCH_OFFSET_Y) || defined(TOUCH_ORIENTATION))
+ #if defined(XPT2046_X_CALIBRATION) && defined(XPT2046_Y_CALIBRATION) && defined(XPT2046_X_OFFSET) && defined(XPT2046_Y_OFFSET)
+ #define TOUCH_CALIBRATION_X XPT2046_X_CALIBRATION
+ #define TOUCH_CALIBRATION_Y XPT2046_Y_CALIBRATION
+ #define TOUCH_OFFSET_X XPT2046_X_OFFSET
+ #define TOUCH_OFFSET_Y XPT2046_Y_OFFSET
+ #define TOUCH_ORIENTATION TOUCH_LANDSCAPE
+ #else
+ #define TOUCH_CALIBRATION_X 0
+ #define TOUCH_CALIBRATION_Y 0
+ #define TOUCH_OFFSET_X 0
+ #define TOUCH_OFFSET_Y 0
+ #define TOUCH_ORIENTATION TOUCH_ORIENTATION_NONE
+ #endif
+#endif
+
+typedef struct __attribute__((__packed__)) {
+ int32_t x;
+ int32_t y;
+ int16_t offset_x;
+ int16_t offset_y;
+ uint8_t orientation;
+} touch_calibration_t;
+
+typedef struct __attribute__((__packed__)) {
+ uint16_t x;
+ uint16_t y;
+ int16_t raw_x;
+ int16_t raw_y;
+} touch_calibration_point_t;
+
+enum calibrationState : uint8_t {
+ CALIBRATION_TOP_LEFT = 0x00,
+ CALIBRATION_BOTTOM_LEFT,
+ CALIBRATION_TOP_RIGHT,
+ CALIBRATION_BOTTOM_RIGHT,
+ CALIBRATION_SUCCESS,
+ CALIBRATION_FAIL,
+ CALIBRATION_NONE,
+};
+
+class TouchCalibration {
+public:
+ static calibrationState calibration_state;
+ static touch_calibration_point_t calibration_points[4];
+
+ static bool validate_precision(int32_t a, int32_t b) { return (a > b ? (100 * b) / a : (100 * a) / b) > TOUCH_SCREEN_CALIBRATION_PRECISION; }
+ static bool validate_precision_x(uint8_t a, uint8_t b) { return validate_precision(calibration_points[a].raw_x, calibration_points[b].raw_x); }
+ static bool validate_precision_y(uint8_t a, uint8_t b) { return validate_precision(calibration_points[a].raw_y, calibration_points[b].raw_y); }
+
+ static touch_calibration_t calibration;
+ static void calibration_reset() { calibration = {TOUCH_CALIBRATION_X, TOUCH_CALIBRATION_Y, TOUCH_OFFSET_X, TOUCH_OFFSET_Y, TOUCH_ORIENTATION}; }
+
+ static calibrationState calibration_start() {
+ calibration = {0, 0, 0, 0, TOUCH_ORIENTATION_NONE};
+ calibration_state = CALIBRATION_TOP_LEFT;
+ calibration_points[CALIBRATION_TOP_LEFT].x = 20;
+ calibration_points[CALIBRATION_TOP_LEFT].y = 20;
+ calibration_points[CALIBRATION_BOTTOM_LEFT].x = 20;
+ calibration_points[CALIBRATION_BOTTOM_LEFT].y = TFT_HEIGHT - 21;
+ calibration_points[CALIBRATION_TOP_RIGHT].x = TFT_WIDTH - 21;
+ calibration_points[CALIBRATION_TOP_RIGHT].y = 20;
+ calibration_points[CALIBRATION_BOTTOM_RIGHT].x = TFT_WIDTH - 21;
+ calibration_points[CALIBRATION_BOTTOM_RIGHT].y = TFT_HEIGHT - 21;
+ return calibration_state;
+ }
+ static void calibration_end() { calibration_state = CALIBRATION_NONE; }
+ static calibrationState get_calibration_state() { return calibration_state; }
+
+ static bool handleTouch(uint16_t x, uint16_t y);
+};
+
+extern TouchCalibration touch_calibration;
+
+#endif