add on-board display PIN_TFT_* for CLUE

back light is disable when powering up

Author: hathach

libraries/Bluefruit52Lib/examples/Peripheral/image_upload/image_upload.ino

@@ -34,7 +34,7 @@
 #elif defined(ARDUINO_NRF52840_CLUE)
   // CLUE use on-board TFT
   #include "Adafruit_ST7789.h"
-  Adafruit_ST7789 tft = Adafruit_ST7789(&SPI1, 31, 32, 33); // CS = 31, DC = 32, RST = 33
+  Adafruit_ST7789 tft = Adafruit_ST7789(&SPI1, PIN_TFT_CS, PIN_TFT_DC, PIN_TFT_RST);
 
 #else
   #define TFT_35_FEATHERWING  1
@@ -115,7 +115,7 @@ void setup()
   tft.init(240, 240);
   tft.setRotation(2);
 
-  // turn backlight on
+  // turn back light on
   uint8_t backlight = A3;
   pinMode(backlight, OUTPUT);
   digitalWrite(backlight, HIGH);
@@ -128,6 +128,11 @@ void setup()
   uint8_t rtna = 0x01;
   tft.sendCommand(0xC6, &rtna, 1);;
 
+  // turn back light on
+  uint8_t backlight = PIN_TFT_LITE;
+  pinMode(backlight, OUTPUT);
+  digitalWrite(backlight, HIGH);
+
 #else
   tft.begin();
 

variants/clue_nrf52840/variant.cpp

@@ -89,5 +89,9 @@ void initVariant()
   // LED1
   pinMode(PIN_LED1, OUTPUT);
   ledOff(PIN_LED1);
+
+  // Disable TFT LITE powering up
+  pinMode(PIN_TFT_LITE, OUTPUT);
+  digitalWrite(PIN_TFT_LITE, LOW);
 }
 

variants/clue_nrf52840/variant.h

@@ -142,6 +142,12 @@ static const uint8_t SCK1  = PIN_SPI1_SCK ;
 #define EXTERNAL_FLASH_DEVICES   GD25Q16C
 #define EXTERNAL_FLASH_USE_QSPI
 
+// On-board TFT display
+#define PIN_TFT_CS           31
+#define PIN_TFT_DC           32
+#define PIN_TFT_RST          33
+#define PIN_TFT_LITE         34
+
 #ifdef __cplusplus
 }
 #endif