Add screen detection function (meshtastic#5533)

src/mesh/NodeDB.cpp

@@ -70,6 +70,76 @@ static unsigned char userprefs_admin_key_1[] = USERPREFS_USE_ADMIN_KEY_1;
 static unsigned char userprefs_admin_key_2[] = USERPREFS_USE_ADMIN_KEY_2;
 #endif
 
+#ifdef HELTEC_MESH_NODE_T114
+
+uint32_t read8(uint8_t bits, uint8_t dummy,uint8_t cs,uint8_t sck,uint8_t mosi,uint8_t dc,uint8_t rst)
+{
+    uint32_t ret = 0;
+    uint8_t SDAPIN = mosi;
+    pinMode(SDAPIN, INPUT_PULLUP);
+    digitalWrite(dc, HIGH);
+    for (int i = 0; i < dummy; i++) {  //any dummy clocks
+        digitalWrite(sck, HIGH);
+        delay(1);
+        digitalWrite(sck, LOW);
+        delay(1);
+    }
+    for (int i = 0; i < bits; i++) {  // read results
+        ret <<= 1;
+        delay(1);
+        if (digitalRead(SDAPIN)) ret |= 1;;
+        digitalWrite(sck, HIGH);
+        delay(1);
+        digitalWrite(sck, LOW);
+    }
+    return ret;
+}
+
+void write9(uint8_t val, uint8_t dc_val,uint8_t cs,uint8_t sck,uint8_t mosi,uint8_t dc,uint8_t rst)
+{
+    pinMode(mosi, OUTPUT);
+    digitalWrite(dc, dc_val);
+    for (int i = 0; i < 8; i++) {   //send command
+        digitalWrite(mosi, (val & 0x80) != 0);
+        delay(1);
+        digitalWrite(sck, HIGH);
+        delay(1);
+        digitalWrite(sck, LOW);
+        val <<= 1;
+    }
+}
+
+uint32_t readwrite8(uint8_t cmd, uint8_t bits, uint8_t dummy,uint8_t cs,uint8_t sck,uint8_t mosi,uint8_t dc,uint8_t rst)
+{
+    digitalWrite(cs, LOW);
+    write9(cmd, 0,cs,sck,mosi,dc,rst);
+    uint32_t ret = read8(bits, dummy,cs,sck,mosi,dc,rst);
+    digitalWrite(cs, HIGH);
+    return ret;
+}
+
+uint32_t get_st7789_id(uint8_t cs,uint8_t sck,uint8_t mosi,uint8_t dc,uint8_t rst)
+{
+    pinMode(cs, OUTPUT);
+    digitalWrite(cs, HIGH);
+    pinMode(cs, OUTPUT);
+    pinMode(sck, OUTPUT);
+    pinMode(mosi, OUTPUT);
+    pinMode(dc, OUTPUT);
+    pinMode(rst, OUTPUT);
+    digitalWrite(rst, LOW);   //Hardware Reset
+    delay(10);
+    digitalWrite(rst, HIGH);
+    delay(10);
+
+    uint32_t ID = 0;
+    ID = readwrite8(0x04, 24, 1,cs,sck,mosi,dc,rst);
+    ID = readwrite8(0x04, 24, 1,cs,sck,mosi,dc,rst);  //ST7789 needs twice
+    return ID;
+}
+
+#endif
+
 bool meshtastic_DeviceState_callback(pb_istream_t *istream, pb_ostream_t *ostream, const pb_field_iter_t *field)
 {
     if (ostream) {
@@ -489,6 +559,13 @@ void NodeDB::installDefaultConfig(bool preserveKey = false)
 #if defined(ST7735_CS) || defined(USE_EINK) || defined(ILI9341_DRIVER) || defined(ILI9342_DRIVER) || defined(ST7789_CS) ||       \
     defined(HX8357_CS) || defined(USE_ST7789)
     bool hasScreen = true;
+#ifdef HELTEC_MESH_NODE_T114
+    uint32_t st7789_id=get_st7789_id(ST7789_NSS,ST7789_SCK,ST7789_SDA,ST7789_RS,ST7789_RESET);
+    if(st7789_id==0xFFFFFF)
+    {
+        hasScreen = false;
+    }
+#endif
 #elif ARCH_PORTDUINO
     bool hasScreen = false;
     if (settingsMap[displayPanel])