From 12f68646e81d787f86f00af4843a2015f08eb1fc Mon Sep 17 00:00:00 2001
From: lewisxhe <lewishe@outlook.com>
Date: Wed, 4 Sep 2024 09:33:21 +0800
Subject: [PATCH] lvgl_example Touch interrupt  method
 https://github.com/Xinyuan-LilyGO/T-Deck/issues/42

---
 examples/lvgl_example/lvgl_example.ino | 60 +++++++++++++++++++++++---
 1 file changed, 54 insertions(+), 6 deletions(-)

diff --git a/examples/lvgl_example/lvgl_example.ino b/examples/lvgl_example/lvgl_example.ino
index 93b3fb8..3f3eb6d 100644
--- a/examples/lvgl_example/lvgl_example.ino
+++ b/examples/lvgl_example/lvgl_example.ino
@@ -8,8 +8,46 @@
 static void slider_event_cb(lv_event_t *e);
 static lv_obj_t *slider_label;
 
-TouchLib touch = TouchLib(Wire, BOARD_I2C_SDA, BOARD_I2C_SCL, GT911_SLAVE_ADDRESS1);
 TFT_eSPI        tft;
+TouchLib    *touch = NULL;
+uint8_t     touchAddress = GT911_SLAVE_ADDRESS2;
+
+void scanDevices(TwoWire *w)
+{
+    uint8_t err, addr;
+    int nDevices = 0;
+    uint32_t start = 0;
+    for (addr = 1; addr < 127; addr++) {
+        start = millis();
+        w->beginTransmission(addr); delay(2);
+        err = w->endTransmission();
+        if (err == 0) {
+            nDevices++;
+            Serial.print("I2C device found at address 0x");
+            if (addr < 16) {
+                Serial.print("0");
+            }
+            Serial.print(addr, HEX);
+            Serial.println(" !");
+
+            if (addr == GT911_SLAVE_ADDRESS2) {
+                touchAddress = GT911_SLAVE_ADDRESS2;
+                Serial.println("Find GT911 Drv Slave address: 0x14");
+            } else if (addr == GT911_SLAVE_ADDRESS1) {
+                touchAddress = GT911_SLAVE_ADDRESS1;
+                Serial.println("Find GT911 Drv Slave address: 0x5D");
+            }
+        } else if (err == 4) {
+            Serial.print("Unknow error at address 0x");
+            if (addr < 16) {
+                Serial.print("0");
+            }
+            Serial.println(addr, HEX);
+        }
+    }
+    if (nDevices == 0)
+        Serial.println("No I2C devices found\n");
+}
 
 
 // LilyGo  T-Deck  control backlight chip has 16 levels of adjustment range
@@ -54,15 +92,15 @@ static void disp_flush( lv_disp_drv_t *disp, const lv_area_t *area, lv_color_t *
     lv_disp_flush_ready( disp );
 }
 
-static volatile bool touch_irq = false;
 
 static bool getTouch(int16_t &x, int16_t &y)
 {
+    if (! digitalRead(BOARD_TOUCH_INT))return false;
     uint8_t rotation = tft.getRotation();
-    if (!touch.read()) {
+    if (!touch->read()) {
         return false;
     }
-    TP_Point t = touch.getPoint(0);
+    TP_Point t = touch->getPoint(0);
     switch (rotation) {
     case 1:
         x = t.y;
@@ -191,9 +229,19 @@ void setup()
     tft.fillScreen(TFT_BLACK);
 
     // Set touch int input
-    pinMode(BOARD_TOUCH_INT, INPUT); delay(20);
+    pinMode(BOARD_TOUCH_INT, INPUT);
+    delay(20);
+
+    Wire.begin(BOARD_I2C_SDA, BOARD_I2C_SCL);
+
+
+    // Two touch screens, the difference between them is the device address,
+    // use ScanDevices to get the existing I2C address
+    scanDevices(&Wire);
+
+    touch = new TouchLib(Wire, BOARD_I2C_SDA, BOARD_I2C_SCL, touchAddress);
 
-    touch.init();
+    touch->init();
 
     setupLvgl();