/*
* clear_screen - clear screen 'cause lcm command
* may result in other side effect
* so clear screen manual.
* @return : status
*/
int clear_screen(void)
{
/*
* lcm clear is OK
*/
return lcm_clear();
}
void lcm_init()
{
bcm2835_spi_begin();
bcm2835_spi_setBitOrder(BCM2835_SPI_BIT_ORDER_MSBFIRST);
bcm2835_spi_setDataMode(BCM2835_SPI_MODE3);
bcm2835_spi_setClockDivider(BCM2835_SPI_CLOCK_DIVIDER_64);
/* 64=250ns=4MHz | works up to 16 | unstable 8 | unusable 4 */
bcm2835_spi_chipSelect(BCM2835_SPI_CS_NONE);
bcm2835_gpio_fsel(A0, BCM2835_GPIO_FSEL_OUTP);
bcm2835_gpio_fsel(RST, BCM2835_GPIO_FSEL_OUTP);
bcm2835_delayMicroseconds(1);
// Reset
bcm2835_gpio_write(RST, LOW);
bcm2835_delayMicroseconds(10);
bcm2835_gpio_write(RST, HIGH);
lcm_set_command();
bcm2835_spi_transfer(0xAE); // turn off the screen
bcm2835_spi_transfer(0xD5); // set display clock divide ratio/oscillator frequency
bcm2835_spi_transfer(0x80); // suggested ratio: 0x80
bcm2835_spi_transfer(0xA8); // set multiplex
bcm2835_spi_transfer(0x3F); // height: 64
bcm2835_spi_transfer(0xD3); // set display offset
bcm2835_spi_transfer(0x00); // offset: 0
bcm2835_spi_transfer(0x40 | 0x0); // set start line
bcm2835_spi_transfer(0x8D); // set charge pump
bcm2835_spi_transfer(0x14); // charge pump: disable
bcm2835_spi_transfer(0x20); // set memory mode
bcm2835_spi_transfer(0x00); // mode: 0
bcm2835_spi_transfer(0xA0 | 0x1); // set seg/column mapping
bcm2835_spi_transfer(0xC8); // set com/row scan direction
bcm2835_spi_transfer(0xDA); // set com pins hardware configuration
bcm2835_spi_transfer(0x12); // compins: 0x12
bcm2835_spi_transfer(0x81); // set contrast control register
bcm2835_spi_transfer(0xCF); // brightness: 0xCF
bcm2835_spi_transfer(0xD9); // set pre-charge period
bcm2835_spi_transfer(0xF1); // pre-charge: 15 clocks / discharge: 1 clock
bcm2835_spi_transfer(0XDB); // set vcom detect
bcm2835_spi_transfer(0x40); // vcom deselect level: 0x40
bcm2835_spi_transfer(0xA4); // disable entire display
bcm2835_spi_transfer(0xA6); // disable inverse display (normal display)
bcm2835_spi_transfer(0xAF); // turn on the screen
lcm_clear();
}
