Function _setup_gpio

boards/m5stack-cplus2/interface.cpp:9–38

** Function name: _setup_gpio() ** Location: main.cpp ** Description: initial setup for the device ***************************************************************************************/

** Description:   initial setup for the device
***************************************************************************************/
void _setup_gpio() {
    pinMode(UP_BTN, INPUT); // Sets the power btn as an INPUT
    pinMode(SEL_BTN, INPUT);
    pinMode(DW_BTN, INPUT);
    pinMode(4, OUTPUT);    // Keeps the Stick alive after take off the USB cable
    digitalWrite(4, HIGH); // Keeps the Stick alive after take off the USB cable
    gpio_pulldown_dis(GPIO_NUM_36);
    gpio_pullup_dis(GPIO_NUM_36);
    pinMode(32, OUTPUT);
    pinMode(33, OUTPUT);
    digitalWrite(32, LOW);
    digitalWrite(33, HIGH);
    //=========================================================================
    // Issue: During startup, the SD card might keep the MISO line at a high level continuously, causing RF
    // initialization to fail. Solution：Forcing switch to SD card and sending dummy clocks
    //=========================================================================
    int pin_shared_ctrl = 33; // Controls CS: HIGH=SD_Select, LOW=RF_Select
    int pin_sck = 0;          // SCK Pin for M5StickC Plus 2
    pinMode(pin_shared_ctrl, OUTPUT);
    pinMode(pin_sck, OUTPUT);
    digitalWrite(pin_shared_ctrl, HIGH); // Force Select SD Card
    delay(10);
    for (int i = 0; i < 80; i++) {
        digitalWrite(pin_sck, HIGH);
        delayMicroseconds(10);
        digitalWrite(pin_sck, LOW);
        delayMicroseconds(10);
    } // send dummy clocks
    digitalWrite(pin_shared_ctrl, HIGH); // Keep the SD card selected.
}

/*********************************************************************
** Function: setBrightness