first commit

main/drivers/i2c_bus.c

@@ -0,0 +1,61 @@
+#include "esp_check.h"
+#include "esp_log.h"
+
+#include "i2c_bus.h"
+
+static const char *TAG = "i2c_bus";
+
+/*
+ * CrowPanel 7" Advance pins. The Basic model uses 19/20 instead -- and on the
+ * ESP32-S3 those are the native USB D-/D+ pins, which is a separate trap.
+ */
+#define I2C_BUS_SDA_GPIO 15
+#define I2C_BUS_SCL_GPIO 16
+#define I2C_BUS_PORT     I2C_NUM_0
+
+static i2c_master_bus_handle_t bus = NULL;
+
+esp_err_t i2c_bus_init(void)
+{
+    if (bus != NULL) {
+        return ESP_OK;
+    }
+
+    const i2c_master_bus_config_t cfg = {
+        .i2c_port = I2C_BUS_PORT,
+        .sda_io_num = I2C_BUS_SDA_GPIO,
+        .scl_io_num = I2C_BUS_SCL_GPIO,
+        .clk_source = I2C_CLK_SRC_DEFAULT,
+        .glitch_ignore_cnt = 7,
+        .flags.enable_internal_pullup = true,
+    };
+
+    ESP_RETURN_ON_ERROR(i2c_new_master_bus(&cfg, &bus), TAG, "i2c bus init failed");
+    ESP_LOGI(TAG, "I2C bus up on SDA=%d SCL=%d", I2C_BUS_SDA_GPIO, I2C_BUS_SCL_GPIO);
+    return ESP_OK;
+}
+
+i2c_master_bus_handle_t i2c_bus_get(void)
+{
+    return bus;
+}
+
+void i2c_bus_scan(const char *tag)
+{
+    if (bus == NULL) {
+        ESP_LOGW(tag, "I2C bus not initialized");
+        return;
+    }
+
+    int n = 0;
+    for (uint8_t addr = 0x03; addr < 0x78; addr++) {
+        if (i2c_master_probe(bus, addr, 20) == ESP_OK) {
+            const char *what = "?";
+            if (addr == 0x30) what = "STC8H1K28 board controller";
+            else if (addr == 0x5D || addr == 0x14) what = "GT911 touch";
+            ESP_LOGI(tag, "  I2C 0x%02X  %s", addr, what);
+            n++;
+        }
+    }
+    ESP_LOGI(tag, "  %d device(s) on the bus", n);
+}