feat:

README.md

@@ -1,3 +1,36 @@
-# esp_component_template
+#include "zh_mcp23s17.h"
 
-esp_component_template
+#define SPI_HOST (SPI_HOST_MAX - 1)
+
+spi_device_handle_t mcp23s17_handle = NULL;
+
+// To speed up transfers, every SPI transfer sends a bunch of lines. This define specifies how many. More means more memory use,
+// but less overhead for setting up / finishing transfers. Make sure 240 is dividable by this.
+#define PARALLEL_LINES 16
+
+void app_main(void)
+{
+    esp_err_t ret;
+    spi_device_handle_t spi;
+    spi_bus_config_t buscfg = {
+        .miso_io_num = 25,
+        .mosi_io_num = 23,
+        .sclk_io_num = 19,
+        .quadwp_io_num = -1,
+        .quadhd_io_num = -1,
+        .max_transfer_sz = 16 * 320 * 2 + 8};
+
+    spi_device_interface_config_t devcfg = {
+        .clock_speed_hz = 10 * 1000 * 1000, // Clock out at 10 MHz
+        .mode = 0,                          // SPI mode 0
+        .spics_io_num = 22,                 // CS pin
+        .queue_size = 7,                    // We want to be able to queue 7 transactions at a time
+        // .pre_cb = lcd_spi_pre_transfer_callback, // Specify pre-transfer callback to handle D/C line
+    };
+    // Initialize the SPI bus
+    ret = spi_bus_initialize(SPI_HOST, &buscfg, SPI_DMA_CH_AUTO);
+    ESP_ERROR_CHECK(ret);
+    // Attach the LCD to the SPI bus
+    ret = spi_bus_add_device(SPI_HOST, &devcfg, &mcp23s17_handle);
+    ESP_ERROR_CHECK(ret);
+}