scan I2C devices if not yet know TOUCH_MODULE_ADDR

Author: moononournation

examples/TouchCalibration/TouchCalibration.ino

@@ -9,7 +9,7 @@
  *
  * Resistive touchscreen libraries
  * XPT2046: https://github.com/PaulStoffregen/XPT2046_Touchscreen.git
- * 
+ *
  * Capacitive touchscreen libraries
  * TouchLib: https://github.com/mmMicky/TouchLib.git
  ******************************************************************************/
@@ -95,6 +95,23 @@ void setup(void)
   h = gfx->height();
   touch_init(w, h, gfx->getRotation());
 
+// not yet know TOUCH_MODULE_ADDR, scan I2C devices
+#if defined(TOUCH_SDA) && !defined(TOUCH_MODULE_ADDR)
+  for (uint8_t addr = 0x01; addr < 0x7f; addr++)
+  {
+    Wire.beginTransmission(addr);
+    uint8_t error = Wire.endTransmission();
+    if (error == 0)
+    {
+      Serial.printf("I2C device found at 0x%02X\n", addr);
+    }
+    else if (error != 2)
+    {
+      Serial.printf("Error %d at 0x%02X\n", error, addr);
+    }
+  }
+#endif
+
   // Top left
   point_x[0] = w / 8;
   point_y[0] = h / 8;

examples/TouchCalibration/touch.h

@@ -48,13 +48,17 @@ int16_t touch_max_x = 0, touch_max_y = 0;
 int16_t touch_raw_x = 0, touch_raw_y = 0;
 int16_t touch_last_x = 0, touch_last_y = 0;
 
+#if defined(TOUCH_SDA)
+#include <Wire.h>
+#endif
+
 #if defined(TOUCH_XPT2046)
 #include <XPT2046_Touchscreen.h>
 #include <SPI.h>
 XPT2046_Touchscreen ts(TOUCH_XPT2046_CS, TOUCH_XPT2046_INT);
 
 #elif defined(TOUCH_MODULE_ADDR) // TouchLib
-#include <Wire.h>
+
 #include <TouchLib.h>
 TouchLib touch(Wire, TOUCH_SDA, TOUCH_SCL, TOUCH_MODULE_ADDR);
 
@@ -99,21 +103,26 @@ void touch_init(int16_t w, int16_t h, uint8_t r)
     }
   }
 
-#if defined(TOUCH_XPT2046)
-  SPI.begin(TOUCH_XPT2046_SCK, TOUCH_XPT2046_MISO, TOUCH_XPT2046_MOSI, TOUCH_XPT2046_CS);
-  ts.begin();
-  ts.setRotation(TOUCH_XPT2046_ROTATION);
-
-#elif defined(TOUCH_MODULE_ADDR) // TouchLib
   // Reset touchscreen
-#if (TOUCH_RES > 0)
+#if defined(TOUCH_RES) && (TOUCH_RES > 0)
   pinMode(TOUCH_RES, OUTPUT);
   digitalWrite(TOUCH_RES, 0);
   delay(200);
   digitalWrite(TOUCH_RES, 1);
   delay(200);
 #endif
+
+#if defined(TOUCH_SDA)
   Wire.begin(TOUCH_SDA, TOUCH_SCL);
+#endif
+
+#if defined(TOUCH_XPT2046)
+  SPI.begin(TOUCH_XPT2046_SCK, TOUCH_XPT2046_MISO, TOUCH_XPT2046_MOSI, TOUCH_XPT2046_CS);
+  ts.begin();
+  ts.setRotation(TOUCH_XPT2046_ROTATION);
+
+#elif defined(TOUCH_MODULE_ADDR) // TouchLib
+
   touch.init();
 
 #endif // TouchLib