added i2c bus scan functionality

components/common/include/legos_i2c.h

+#include "driver/i2c.h"
+#include "driver/gpio.h"
+
+/**
+ * @brief Scans the I2C bus and visualizes found devices
+ *
+ * @param[in] port I2C port to scan
+ * @param[in] gpio_sda SDA pin nr.
+ * @param[in] gpio_scl SCL pin nr.
+ * @param[in] frequency I2C bus frequency
+ */
+void i2c_bus_scan(i2c_port_t port, gpio_num_t gpio_sda, gpio_num_t gpio_scl,
+    uint32_t frequency);
+

components/common/src/legos_i2c.c

+#include "driver/i2c.h"
+#include "esp_log.h"
+
+static const char* TAG = "LEGOS I2C";
+
+#define I2C_MASTER_TX_BUF_DISABLE 0
+#define I2C_MASTER_RX_BUF_DISABLE 0
+#define WRITE_BIT I2C_MASTER_WRITE
+#define READ_BIT I2C_MASTER_READ
+#define ACK_CHECK_EN 0x1
+#define ACK_CHECK_DIS 0x0
+
+static esp_err_t i2c_master_driver_initialize(i2c_port_t port,
+    gpio_num_t gpio_sda, gpio_num_t gpio_scl, uint32_t frequency)
+{
+    i2c_config_t conf = {
+        .mode = I2C_MODE_MASTER,
+        .sda_io_num = gpio_sda,
+        .sda_pullup_en = GPIO_PULLUP_ENABLE,
+        .scl_io_num = gpio_scl,
+        .scl_pullup_en = GPIO_PULLUP_ENABLE,
+        .master.clk_speed = frequency,
+        // .clk_flags = 0,          /*!< Optional, you can use
+        // I2C_SCLK_SRC_FLAG_* flags to choose i2c source clock here. */
+    };
+    return i2c_param_config(port, &conf);
+}
+
+void i2c_bus_scan(i2c_port_t port, gpio_num_t gpio_sda,
+    gpio_num_t gpio_scl, uint32_t frequency)
+{
+    i2c_master_driver_initialize(port, gpio_sda, gpio_scl, frequency);
+    i2c_driver_install(port, I2C_MODE_MASTER, I2C_MASTER_RX_BUF_DISABLE,
+        I2C_MASTER_TX_BUF_DISABLE, 0);
+    uint8_t address;
+    printf("I2C Bus Map\n");
+    printf("     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f\r\n");
+    for (int i = 0; i < 128; i += 16) {
+        printf("%02x: ", i);
+        for (int j = 0; j < 16; j++) {
+            fflush(stdout);
+            address = i + j;
+            i2c_cmd_handle_t cmd = i2c_cmd_link_create();
+            i2c_master_start(cmd);
+            i2c_master_write_byte(
+                cmd, (address << 1) | WRITE_BIT, ACK_CHECK_EN);
+            i2c_master_stop(cmd);
+            esp_err_t ret
+                = i2c_master_cmd_begin(port, cmd, 50 / portTICK_PERIOD_MS);
+            i2c_cmd_link_delete(cmd);
+            if (ret == ESP_OK) {
+                printf("%02x ", address);
+            } else if (ret == ESP_ERR_TIMEOUT) {
+                printf("UU ");
+            } else {
+                printf("-- ");
+            }
+        }
+        printf("\r\n");
+    }
+
+    i2c_driver_delete(port);
+}