nanor4: add 3v3 regulator on/off pin

Author: facchinm

variants/NANOR4/pins_arduino.h

@@ -174,6 +174,11 @@ static const uint8_t SS  =  PIN_SPI_CS;
 
 #define VUSB_LDO_ENABLE     1
 
+// Use this define to shutdown the 3V3 regulator
+// pinMode(ENABLE_3V3, OUTPUT);
+// digitalWrite(ENABLE_3V3, LOW);
+#define ENABLE_3V3          28
+
 /* EEPROM DEFINES */
 
 #define ARDUINO_FLASH_TYPE  LP_FLASH

variants/NANOR4/variant.cpp

@@ -56,6 +56,7 @@ extern "C" const PinMuxCfg_t g_pin_cfg[] = {
   { BSP_IO_PORT_04_PIN_00,    P400   }, /* (26) QWIIK SCL  */
   { BSP_IO_PORT_04_PIN_01,    P401   }, /* (27) QWIIK SDA  */
 
+  { BSP_IO_PORT_05_PIN_00,    P500   }, /* (28) 3V3 enable  */
 };
 
 extern "C" {