fix i2c scan printf to uart data transmit

Inc/i2c.h

@@ -39,7 +39,10 @@ typedef enum {
     I2C_RESULT_NACK,            /* No acknowledge received */
     I2C_RESULT_BUS_BUSY,        /* Bus is busy */
     I2C_RESULT_ERROR,           /* General error */
-    I2C_RESULT_INVALID_PARAM    /* Invalid parameter */
+    I2C_RESULT_INVALID_PARAM,   /* Invalid parameter */
+    I2C_RECOVERY_OK,
+    I2C_RECOVERY_SDA_STUCK_LOW,
+    I2C_RECOVERY_SCL_STUCK_LOW
 } i2c_result_t;
 
 /* I2C state machine enumeration */
@@ -69,24 +72,21 @@ typedef enum {
 
 
 /* Function declarations */
-
-// TODO I2C Result
 /*!
     \brief      configure the I2C interface
     \param[in]  none
     \param[out] none
     \retval     i2c_result_t
 */
-void i2c_config(void);
+i2c_result_t i2c_config(void);
 
-// TODO I2C Result
 /*!
     \brief      reset I2C bus with proper recovery
     \param[in]  none
     \param[out] none
     \retval     i2c_result_t
 */
-void i2c_bus_reset(void);
+i2c_result_t i2c_bus_reset(void);
 
 /*!
     \brief      scan I2C bus for devices

Src/i2c.c

@@ -31,7 +31,7 @@ void i2c_gpio_config(void) {
     \param[out] none
     \retval     none
 */
-void i2c_config(void) {
+i2c_result_t i2c_config(void) {
     /* configure I2C GPIO */
     i2c_gpio_config();
     /* enable I2C clock */
@@ -44,6 +44,27 @@ void i2c_config(void) {
     i2c_enable(I2C0);
     /* enable acknowledge */
     i2c_ack_config(I2C0, I2C_ACK_ENABLE);
+
+    return I2C_RESULT_SUCCESS;
+}
+
+/* wait for SCL to go high, return true if successful, false if timeout */
+static bool i2c_wait_scl_high(uint16_t max_wait_time) {
+    while (max_wait_time--) {
+        if (gpio_input_bit_get(I2C_SCL_PORT, I2C_SCL_PIN)) {
+            return true;
+        }
+        delay_10us(1);
+    }
+    return false;
+}
+
+/* generate one manual SCL pulse; return true if SCL observed high (no stuck/overstretch) */
+static bool i2c_generate_scl_pulse(void) {
+    GPIO_BC(I2C_SCL_PORT) = I2C_SCL_PIN;   /* drive SCL low */
+    delay_10us(1);
+    GPIO_BOP(I2C_SCL_PORT) = I2C_SCL_PIN;  /* release SCL (open-drain -> high via pull-up) */
+    return i2c_wait_scl_high(200);         /* wait up to ~2ms for clock stretching release */
 }
 
 /*!
@@ -52,31 +73,87 @@ void i2c_config(void) {
     \param[out] none
     \retval     none
 */
-void i2c_bus_reset(void) {
+i2c_result_t i2c_bus_reset(void) {
+    /* 1. Disable & deinit peripheral so pins can be fully controlled */
+    i2c_disable(I2C0);
     i2c_deinit(I2C0);
-    /* configure SDA/SCL for GPIO */
-    GPIO_BC(I2C_SCL_PORT) |= I2C_SCL_PIN;
-    GPIO_BC(I2C_SDA_PORT) |= I2C_SDA_PIN;
-    gpio_output_options_set(I2C_SCL_PORT, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, I2C_SCL_PIN);
-    gpio_output_options_set(I2C_SDA_PORT, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, I2C_SDA_PIN);
-    __NOP();
-    __NOP();
-    __NOP();
-    __NOP();
-    __NOP();
-    GPIO_BOP(I2C_SCL_PORT) |= I2C_SCL_PIN;
-    __NOP();
-    __NOP();
-    __NOP();
-    __NOP();
-    __NOP();
-    GPIO_BOP(I2C_SDA_PORT) |= I2C_SDA_PIN;
-    /* connect I2C_SCL_PIN to I2C_SCL */
-    /* connect I2C_SDA_PIN to I2C_SDA */
+
+#ifdef DEBUG_VERBOSE
+    printf("I2C bus reset\r\n");
+#endif
+
+    /* 2. Configure SCL/SDA as GPIO open-drain outputs with pull-up and release them */
+    gpio_mode_set(I2C_SCL_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_PULLUP, I2C_SCL_PIN);
+    gpio_mode_set(I2C_SDA_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_PULLUP, I2C_SDA_PIN);
     gpio_output_options_set(I2C_SCL_PORT, GPIO_OTYPE_OD, GPIO_OSPEED_50MHZ, I2C_SCL_PIN);
     gpio_output_options_set(I2C_SDA_PORT, GPIO_OTYPE_OD, GPIO_OSPEED_50MHZ, I2C_SDA_PIN);
-    /* configure the I2CX interface */
+    gpio_bit_set(I2C_SCL_PORT, I2C_SCL_PIN); /* release SCL */
+    gpio_bit_set(I2C_SDA_PORT, I2C_SDA_PIN); /* release SDA */
+
+#ifdef DEBUG_VERBOSE
+    printf("I2C bus reset: SCL = %d, SDA = %d\r\n", gpio_input_bit_get(I2C_SCL_PORT, I2C_SCL_PIN), gpio_input_bit_get(I2C_SDA_PORT, I2C_SDA_PIN));
+#endif
+
+    /* 3. Double sample to confirm bus state */
+    delay_10us(1);
+    bool scl_value1 = gpio_input_bit_get(I2C_SCL_PORT, I2C_SCL_PIN);
+    bool sda_value1 = gpio_input_bit_get(I2C_SDA_PORT, I2C_SDA_PIN);
+    delay_10us(1);
+    bool scl_value2 = gpio_input_bit_get(I2C_SCL_PORT, I2C_SCL_PIN);
+    bool sda_value2 = gpio_input_bit_get(I2C_SDA_PORT, I2C_SDA_PIN);
+
+    /* 4. If SCL low -> stuck (cannot proceed) */
+    if (!scl_value2) {
+#ifdef DEBUG_VERBOSE
+        printf("I2C bus reset: SCL stuck low\r\n");
+#endif
+        return I2C_RECOVERY_SCL_STUCK_LOW;
+    }
+
+    /* 5. Fast path: bus idle */
+    if (scl_value1 && sda_value1 && scl_value2 && sda_value2) {
+        i2c_config();
+#ifdef DEBUG_VERBOSE
+        printf("I2C bus reset: bus idle\r\n");
+#endif
+        return I2C_RECOVERY_OK;
+    }
+
+    /* 6. SDA low: attempt to free by generating up to I2C_RECOVERY_CLOCKS pulses */
+    if (scl_value2 && !sda_value2) {
+        bool sda_released = false;
+#ifdef DEBUG_VERBOSE
+        printf("I2C bus reset: SCL will try to free SDA\r\n");
+#endif
+        for (uint8_t i = 0; i < I2C_RECOVERY_CLOCKS && !sda_released; i++) {
+            if (!i2c_generate_scl_pulse()) {
+                return I2C_RECOVERY_SCL_STUCK_LOW; /* SCL failed to go high */
+            }
+            if (gpio_input_bit_get(I2C_SDA_PORT, I2C_SDA_PIN)) {
+                sda_released = true;
+            }
+        }
+        if (!sda_released) {
+            return I2C_RECOVERY_SDA_STUCK_LOW;
+        }
+        /* 7. Generate a STOP condition to leave bus in idle state */
+#ifdef DEBUG_VERBOSE
+        printf("I2C bus reset: generating STOP condition\r\n");
+#endif
+        gpio_bit_reset(I2C_SDA_PORT, I2C_SDA_PIN); /* SDA low */
+        delay_10us(1);
+        gpio_bit_set(I2C_SCL_PORT, I2C_SCL_PIN);   /* ensure SCL high */
+        delay_10us(1);
+        gpio_bit_set(I2C_SDA_PORT, I2C_SDA_PIN);   /* SDA rising while SCL high -> STOP */
+        delay_10us(1);
+    }
+
+#ifdef DEBUG_VERBOSE
+        printf("I2C bus reset: bus recovered\r\n");
+#endif
+    /* 8. Reconfigure & enable peripheral */
     i2c_config();
+    return I2C_RECOVERY_OK;
 }
 
 /**
@@ -91,7 +168,13 @@ void i2c_scan(void) {
     uint8_t address;
     int found_devices = 0;
 
-    printf("Scanning I2C bus...\r\n");
+    // printf("Scanning I2C bus...\r\n");
+    const char* msg1 = "Scanning I2C bus...\r\n";
+    for (uint8_t i = 0; msg1[i] != '\0'; i++) {
+        while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
+        usart_data_transmit(I2C_DEBUG_UART, msg1[i]);
+    }
+    while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TC) == RESET) {}
 
     for (address = 1; address < 127; address++) {
         timeout = 0;
@@ -119,7 +202,24 @@ void i2c_scan(void) {
             timeout++;
         if (timeout < I2C_TIME_OUT) {
             i2c_flag_clear(I2C0, I2C_FLAG_ADDSEND);
-            printf("Found device at 0x%02X\r\n", address);
+            // printf("Found device at 0x%02X\r\n", address);
+            const char* msg2_prefix = "Found device at 0x";
+            for (uint8_t i = 0; msg2_prefix[i] != '\0'; i++) {
+                while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
+                usart_data_transmit(I2C_DEBUG_UART, msg2_prefix[i]);
+            }
+            // 发送地址的十六进制表示
+            uint8_t hex_chars[] = "0123456789ABCDEF";
+            while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
+            usart_data_transmit(I2C_DEBUG_UART, hex_chars[(address >> 4) & 0x0F]);
+            while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
+            usart_data_transmit(I2C_DEBUG_UART, hex_chars[address & 0x0F]);
+            const char* msg2_suffix = "\r\n";
+            for (uint8_t i = 0; msg2_suffix[i] != '\0'; i++) {
+                while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
+                usart_data_transmit(I2C_DEBUG_UART, msg2_suffix[i]);
+            }
+            while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TC) == RESET) {}
             found_devices++;
         }
 
@@ -133,9 +233,33 @@ void i2c_scan(void) {
     }
 
     if (found_devices == 0) {
-        printf("No I2C devices found.\r\n");
+        // printf("No I2C devices found.\r\n");
+        const char* msg3 = "No I2C devices found.\r\n";
+        for (uint8_t i = 0; msg3[i] != '\0'; i++) {
+            while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
+            usart_data_transmit(I2C_DEBUG_UART, msg3[i]);
+        }
+        while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TC) == RESET) {}
     } else {
-        printf("Total %d I2C devices found.\r\n", found_devices);
+        // printf("Total %d I2C devices found.\r\n", found_devices);
+        const char* msg4_prefix = "Total ";
+        for (uint8_t i = 0; msg4_prefix[i] != '\0'; i++) {
+            while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
+            usart_data_transmit(I2C_DEBUG_UART, msg4_prefix[i]);
+        }
+        // 发送设备数量
+        if (found_devices >= 10) {
+            while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
+            usart_data_transmit(I2C_DEBUG_UART, '0' + (found_devices / 10));
+        }
+        while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
+        usart_data_transmit(I2C_DEBUG_UART, '0' + (found_devices % 10));
+        const char* msg4_suffix = " I2C devices found.\r\n";
+        for (uint8_t i = 0; msg4_suffix[i] != '\0'; i++) {
+            while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
+            usart_data_transmit(I2C_DEBUG_UART, msg4_suffix[i]);
+        }
+        while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TC) == RESET) {}
     }
 }
 

Src/main.c

@@ -60,7 +60,7 @@ int main(void)
     led_init();
 
 #ifdef DEBUG_VERBOSE
-    char hello_world[] = {"Hello World!"};
+    char hello_world[] = {"Hello World!\r\n"};
 
     for (uint8_t i = 0; i < sizeof(hello_world); i++)
     {
@@ -69,30 +69,23 @@ int main(void)
     }
     
     while (usart_flag_get(RS485_PHY, USART_FLAG_TC) == RESET) {}
-#endif
 
     
+#endif
 
     i2c_config();
 
-    i2c_scan();
-
-    // i2c_bus_reset();
-
-    // uint8_t sensor_data[2] = {0};
-
-    // i2c_read_16bits(0x2B, 0x7E, sensor_data);
-
-    // printf("Sensor Data: 0x%02X 0x%02X\r\n", sensor_data[0], sensor_data[1]);
-
-    // i2c_bus_reset();
-
-    ldc1612_iic_get_sensor_infomation();
-
 #ifdef DEBUG_VERBOSE
     i2c_scan();
+
+    i2c_bus_reset();
 #endif
 
+    i2c_scan();
+    ldc1612_iic_get_sensor_infomation();
+
+
+
     while(1){
         command_process();
         delay_ms(100);

i2c_wait.c

@@ -8,215 +8,6 @@
 /* Private variables */
 static uint8_t i2c_retry_count = 0;
 
-/*!
-    \brief      configure the GPIO ports
-    \param[in]  none
-    \param[out] none
-    \retval     none
-*/
-void i2c_gpio_config(void) {
-    /* enable IIC GPIO clock */
-    rcu_periph_clock_enable(RCU_GPIO_I2C);
-
-    /* connect I2C_SCL_PIN to I2C_SCL */
-    gpio_af_set(I2C_SCL_PORT, I2C_GPIO_AF, I2C_SCL_PIN);
-    /* connect I2C_SDA_PIN to I2C_SDA */
-    gpio_af_set(I2C_SDA_PORT, I2C_GPIO_AF, I2C_SDA_PIN);
-    /* configure GPIO pins of I2C */
-    gpio_mode_set(I2C_SCL_PORT, GPIO_MODE_AF, GPIO_PUPD_PULLUP, I2C_SCL_PIN);
-    gpio_output_options_set(I2C_SCL_PORT, GPIO_OTYPE_OD, GPIO_OSPEED_50MHZ, I2C_SCL_PIN);
-    gpio_mode_set(I2C_SDA_PORT, GPIO_MODE_AF, GPIO_PUPD_PULLUP, I2C_SDA_PIN);
-    gpio_output_options_set(I2C_SDA_PORT, GPIO_OTYPE_OD, GPIO_OSPEED_50MHZ, I2C_SDA_PIN);
-}
-
-/*!
-    \brief      configure the I2CX interface
-    \param[in]  none
-    \param[out] none
-    \retval     i2c_status_t
-*/
-i2c_status_t i2c_config(void) {
-    /* configure I2C GPIO */
-    i2c_gpio_config();
-    
-    /* enable I2C clock */
-    rcu_periph_clock_enable(RCU_I2C);
-    
-    /* configure I2C clock */
-    i2c_clock_config(I2C0, I2C_SPEED, I2C_DTCY_2);
-    
-    /* configure I2C address - use 0x00 as master doesn't need specific address */
-    i2c_mode_addr_config(I2C0, I2C_I2CMODE_ENABLE, I2C_ADDFORMAT_7BITS, I2C_MASTER_ADDRESS);
-    
-    /* enable I2CX */
-    i2c_enable(I2C0);
-    
-    /* enable acknowledge */
-    i2c_ack_config(I2C0, I2C_ACK_ENABLE);
-    
-    /* reset retry counter */
-    i2c_retry_count = 0;
-    
-    return I2C_STATUS_SUCCESS;
-}
-
-/*!
-    \brief      reset I2C bus with proper 9-clock recovery
-    \param[in]  none
-    \param[out] none
-    \retval     i2c_status_t
-*/
-i2c_status_t i2c_bus_reset(void) {
-    uint8_t i;
-    
-    /* disable I2C peripheral */
-    i2c_disable(I2C0);
-    i2c_deinit(I2C0);
-    
-    /* configure SDA/SCL as GPIO output for manual control */
-    gpio_mode_set(I2C_SCL_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_PULLUP, I2C_SCL_PIN);
-    gpio_mode_set(I2C_SDA_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_PULLUP, I2C_SDA_PIN);
-    gpio_output_options_set(I2C_SCL_PORT, GPIO_OTYPE_OD, GPIO_OSPEED_50MHZ, I2C_SCL_PIN);
-    gpio_output_options_set(I2C_SDA_PORT, GPIO_OTYPE_OD, GPIO_OSPEED_50MHZ, I2C_SDA_PIN);
-    
-    /* ensure both lines are high initially */
-    gpio_bit_set(I2C_SCL_PORT, I2C_SCL_PIN);
-    gpio_bit_set(I2C_SDA_PORT, I2C_SDA_PIN);
-    delay_10us(I2C_DELAY_10US);
-    
-    /* generate 9 clock pulses to release any stuck slave */
-    for (i = 0; i < I2C_RECOVERY_CLOCKS; i++) {
-        gpio_bit_reset(I2C_SCL_PORT, I2C_SCL_PIN);
-        delay_10us(I2C_DELAY_10US);
-        gpio_bit_set(I2C_SCL_PORT, I2C_SCL_PIN);
-        delay_10us(I2C_DELAY_10US);
-    }
-    
-    /* generate stop condition */
-    gpio_bit_reset(I2C_SDA_PORT, I2C_SDA_PIN);
-    delay_10us(I2C_DELAY_10US);
-    gpio_bit_set(I2C_SCL_PORT, I2C_SCL_PIN);
-    delay_10us(I2C_DELAY_10US);
-    gpio_bit_set(I2C_SDA_PORT, I2C_SDA_PIN);
-    delay_10us(I2C_DELAY_10US);
-    
-    /* reconfigure as I2C pins */
-    gpio_af_set(I2C_SCL_PORT, I2C_GPIO_AF, I2C_SCL_PIN);
-    gpio_af_set(I2C_SDA_PORT, I2C_GPIO_AF, I2C_SDA_PIN);
-    gpio_mode_set(I2C_SCL_PORT, GPIO_MODE_AF, GPIO_PUPD_PULLUP, I2C_SCL_PIN);
-    gpio_mode_set(I2C_SDA_PORT, GPIO_MODE_AF, GPIO_PUPD_PULLUP, I2C_SDA_PIN);
-    
-    /* reconfigure the I2CX interface */
-    return i2c_config();
-}
-
-/**
- * @brief 扫描I2C总线，查找连接的设备
- *
- * 该函数会扫描I2C总线上的所有地址（1到126），并尝试与每个地址进行通信。
- * 如果在某个地址上发现了设备，则会打印出该设备的地址。
- * 最后会打印出找到的设备总数。
- */
-void i2c_scan(void) {
-    uint32_t timeout;
-    uint8_t address;
-    int found_devices = 0;
-
-    // printf("Scanning I2C bus...\r\n");
-    const char* msg1 = "Scanning I2C bus...\r\n";
-    for (uint8_t i = 0; msg1[i] != '\0'; i++) {
-        while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
-        usart_data_transmit(I2C_DEBUG_UART, msg1[i]);
-    }
-    while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TC) == RESET) {}
-
-    for (address = 1; address < 127; address++) {
-        timeout = 0;
-
-        // 生成起始条件
-        while (i2c_flag_get(I2C0, I2C_FLAG_I2CBSY) && (timeout < I2C_TIME_OUT))
-            timeout++;
-        if (timeout >= I2C_TIME_OUT) {
-            continue; // 超时，跳过该地址
-        }
-        i2c_start_on_bus(I2C0);
-        timeout = 0;
-
-        // 等待起始条件发送完成
-        while (!i2c_flag_get(I2C0, I2C_FLAG_SBSEND) && (timeout < I2C_TIME_OUT))
-            timeout++;
-        if (timeout >= I2C_TIME_OUT) {
-            continue; // 超时，跳过该地址
-        }
-        i2c_master_addressing(I2C0, (address << 1), I2C_TRANSMITTER);
-        timeout = 0;
-
-        // 等待地址发送完成
-        while (!i2c_flag_get(I2C0, I2C_FLAG_ADDSEND) && (timeout < I2C_TIME_OUT))
-            timeout++;
-        if (timeout < I2C_TIME_OUT) {
-            i2c_flag_clear(I2C0, I2C_FLAG_ADDSEND);
-            // printf("Found device at 0x%02X\r\n", address);
-            const char* msg2_prefix = "Found device at 0x";
-            for (uint8_t i = 0; msg2_prefix[i] != '\0'; i++) {
-                while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
-                usart_data_transmit(I2C_DEBUG_UART, msg2_prefix[i]);
-            }
-            // 发送地址的十六进制表示
-            uint8_t hex_chars[] = "0123456789ABCDEF";
-            while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
-            usart_data_transmit(I2C_DEBUG_UART, hex_chars[(address >> 4) & 0x0F]);
-            while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
-            usart_data_transmit(I2C_DEBUG_UART, hex_chars[address & 0x0F]);
-            const char* msg2_suffix = "\r\n";
-            for (uint8_t i = 0; msg2_suffix[i] != '\0'; i++) {
-                while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
-                usart_data_transmit(I2C_DEBUG_UART, msg2_suffix[i]);
-            }
-            while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TC) == RESET) {}
-            found_devices++;
-        }
-
-        // 生成停止条件
-        i2c_stop_on_bus(I2C0);
-
-        timeout = 0;
-
-        while ((I2C_CTL0(I2C0) & I2C_CTL0_STOP) && (timeout < I2C_TIME_OUT))
-            timeout++;
-    }
-
-    if (found_devices == 0) {
-        // printf("No I2C devices found.\r\n");
-        const char* msg3 = "No I2C devices found.\r\n";
-        for (uint8_t i = 0; msg3[i] != '\0'; i++) {
-            while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
-            usart_data_transmit(I2C_DEBUG_UART, msg3[i]);
-        }
-        while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TC) == RESET) {}
-    } else {
-        // printf("Total %d I2C devices found.\r\n", found_devices);
-        const char* msg4_prefix = "Total ";
-        for (uint8_t i = 0; msg4_prefix[i] != '\0'; i++) {
-            while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
-            usart_data_transmit(I2C_DEBUG_UART, msg4_prefix[i]);
-        }
-        // 发送设备数量
-        if (found_devices >= 10) {
-            while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
-            usart_data_transmit(I2C_DEBUG_UART, '0' + (found_devices / 10));
-        }
-        while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
-        usart_data_transmit(I2C_DEBUG_UART, '0' + (found_devices % 10));
-        const char* msg4_suffix = " I2C devices found.\r\n";
-        for (uint8_t i = 0; msg4_suffix[i] != '\0'; i++) {
-            while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
-            usart_data_transmit(I2C_DEBUG_UART, msg4_suffix[i]);
-        }
-        while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TC) == RESET) {}
-    }
-}
-
 /*!
     \brief      write 16-bit data to I2C device with improved state machine
     \param[in]  slave_addr: 7-bit slave address