From 51bdd7233bc55c4e3d051f69853f2507188f5721 Mon Sep 17 00:00:00 2001
From: simon <simon.kruecken@web.de>
Date: Tue, 21 Apr 2026 10:56:00 +0200
Subject: [PATCH] Added I2C IO Expander

---
 main/hw_test.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 54 insertions(+), 1 deletion(-)

diff --git a/main/hw_test.c b/main/hw_test.c
index 94dc37c..f0239d7 100644
--- a/main/hw_test.c
+++ b/main/hw_test.c
@@ -1,9 +1,12 @@
 #include "driver/gpio.h"
+#include "driver/i2c_master.h"
+#include "driver/i2c_types.h"
 #include "esp_err.h"
 #include "esp_log.h"
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
 #include "led_strip.h"
+#include <stdint.h>
 
 #define LED_GPIO 21
 #define TASTER_GPIO 12
@@ -13,15 +16,23 @@
 #define TERMINAL_TX 3
 #define DIP_MASTER 4
 #define I2C_SCL 5
-#define I2C_SDA
+#define I2C_SDA 6
 #define TOUCH_1 9
 #define TOUCH_2 8
 #define LED_RING 7
 
+#define I2C_PORT 0
+#define IO_EXPANDER_ADDRESS 0x20
+#define BMA456_ADDRESS 0x18
+
 static const char *TAG = "LED_TASK";
 static led_strip_handle_t led_strip;
 static led_strip_handle_t led_ring;
 
+static i2c_master_bus_handle_t bus_handle;
+static i2c_master_dev_handle_t io_expander;
+static i2c_master_dev_handle_t bma456_dev_handle;
+
 /* LED Task */
 void vTaskLed(void *pvParameters) {
   ESP_LOGI(TAG, "LED task started");
@@ -126,4 +137,46 @@ void app_main(void) {
   /* Input Monitor Task */
   ESP_LOGI(TAG, "Input Monitor Task");
   xTaskCreate(vTaskInput, "monitor_input", 4096, NULL, 5, NULL);
+
+  /* Init I2C IO Expander */
+  i2c_master_bus_config_t i2c_mst_config = {
+      .clk_source = I2C_CLK_SRC_DEFAULT,
+      .i2c_port = I2C_PORT,
+      .scl_io_num = I2C_SCL,
+      .sda_io_num = I2C_SDA,
+      .glitch_ignore_cnt = 7,
+      .flags.enable_internal_pullup = true,
+  };
+
+  err = i2c_new_master_bus(&i2c_mst_config, &bus_handle);
+  if (err != ESP_OK) {
+    ESP_LOGI(TAG, "I2C Master Could not Init Bus");
+  }
+
+  i2c_device_config_t dev_cfg = {
+      .dev_addr_length = I2C_ADDR_BIT_LEN_7,
+      .device_address = IO_EXPANDER_ADDRESS,
+      .scl_speed_hz = 100000,
+  };
+  err = i2c_master_bus_add_device(bus_handle, &dev_cfg, &io_expander);
+  if (err != ESP_OK) {
+    ESP_LOGI(TAG, "Could not add IO Expnader to Bus %d", err);
+  } else {
+
+    uint8_t write_buf[2] = {0x03, 0xFF}; // 0xFF setzt alle Bits auf Input
+    err = i2c_master_transmit(io_expander, write_buf, sizeof(write_buf), -1);
+    if (err != ESP_OK) {
+      ESP_LOGI(TAG, "Could not set IO Expander in input mode %d", err);
+    }
+
+    uint8_t reg_addr = 0x00;
+    uint8_t read_val = 0;
+
+    err = i2c_master_transmit_receive(io_expander, &reg_addr, 1, &read_val, 1,
+                                      -1);
+    if (err != ESP_OK) {
+      ESP_LOGI(TAG, "Could not read IO Expander input %d", err);
+    }
+    ESP_LOGI(TAG, "Read INPUT %d", read_val);
+  }
 }