Spi serial flash programmer schematic drawing

We could set up another FreeRTOS task that is responsible for coordinating the SPI transactions.There are other ways we could send the framebuffer to the display: We initiate the draw with MEMORY_WRITE and send all 153,600 bytes of the framebuffer to the display in one go. The parameters to these commands require that we separate a 16-bit value into two 8-bit values so that’s what we do. UPPER_BYTE_16 and LOWER_BYTE_16 are convenience macros that extract the upper or lower byte of a 16-bit value. Each takes four parameter bytes which describe the window that we’re Our framerate is suffering and we only want to update the parts of the screen that have changed, but for now we’reĭrawing a frame requires that we set up the drawing window by sending COLUMN_ADDRESS_SET with the window widthĪnd PAGE_ADDRESS_SET with the window height. The ILI9341 allows us to only redraw a certain portion of the screen. To the LCD’s DC pin which controls what type of information we’re sending to the display.Ĭonst gpio_num_t LCD_PIN_MISO = GPIO_NUM_19 const gpio_num_t LCD_PIN_MOSI = GPIO_NUM_23 const gpio_num_t LCD_PIN_SCLK = GPIO_NUM_18 const gpio_num_t LCD_PIN_CS = GPIO_NUM_5 const gpio_num_t LCD_PIN_DC = GPIO_NUM_21 const gpio_num_t LCD_PIN_BACKLIGHT = GPIO_NUM_14 spi_bus_config_t spiBusConfig = There is also IO14 which is a GPIO output that we’ll use to enable the backlight, and IO21 which is connected The VSPI.XXXX names are just labels for the pins in the schematic, but we can follow the path to the true pinĪssignments by looking at the LCD and ESP32 sections of the schematic. Settings and then add the LCD to the bus by configuring the proper pins. We’ll need to configure the SPI bus with requested The ESP32 will be the SPI master and the LCD will be a SPI slave. When that device’s CS signal is activated then it is able to On the same bus with individual CS signals for each. Out Slave In), MISO (Master In Slave Out), SCK (Clock), and CS (Chip Select).Ī single master device on the bus coordinates the data transfers by controlling SCK and CS. SPI is a common protocol used to communicate between devices on a circuit board. The LCD is connected to the ESP32 via SPI (Serial Peripheral Interface).

Spi serial flash programmer schematic drawing