K230 QR code instructions

This tutorial is a comprehensive experiment combining multiple peripherals. You can first understand a single peripheral and then conduct this experiment.

1. Software-Hardware

• STM32F103CubeIDE

• STM32 Robot Development Board

K230 module: external

• Type-C data cable or ST-Link

Download or simulate the development board

2. Brief principle

1. Hardware schematic

2. Physical connection diagram

K230 wiring (Note: The wiring in the figure below is for position reference only. We are equipped with K230 dual-head PH2.0 4Pin all-black wire, with fool-proof design, no need to worry about wiring problems)

Motor wiring

3. Control principle

Program flow chart

Communication protocol:

When k230 recognizes the content of the scanned QR code, it will send a data frame through the serial port, the format is as follows

The microcontroller receives the data sent by k230 through the serial port and processes the data. By judging whether the received data content is in the above frame format, we process the data into string data after it meets the data frame format. It should be distinguished from the previous "x, y, w, h" coordinate information, and then compare this string array. If the comparison is a specific QR code instruction content, the corresponding instruction is executed on the car.

For example: "$XX, 03, XXX, XXX, XXX, XXX, goback#"

When the microcontroller receives the above data frame, it will split the data frame with commas, and the data after the commas is the data we need to obtain. After parsing the data frame content, it will compare this content with goback. If it is the corresponding instruction, the car will move backward.

Note: For the analysis part, please refer to the code

3. Main functions

Function: Car_qcode

Function: Motion_Set_Speed

Function prototype	void Motion_Set_Speed(int16_t speed_m1, int16_t speed_m2, int16_t speed_m3, int16_t speed_m4)
Function description	Control the speed of the car
Input parameters 1, 2, 3, 4	Speed control: speed=0~1000.
Return value	None

Function: wheel_State

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For the underlying driver, please refer to the tutorials in Chapter 3 and Chapter 4
For the application layer, you can read the source code in the project file by yourself

4. Partial code analysis

• yb_protocol.c

x
//*
 * @Brief: 数据分析 Data analysis
 * @Note: 解析传入的数据帧，提取字段值并处理
 *        Parse the incoming data frame, extract field values and process them
 * @Parm: 传入接受到的一个数据帧和长度 Pass in a received data frame and length
 * @Retval: 无返回值 No return value
 */
void Pto_Data_Parse(uint8_t *data_buf, uint8_t num)
{
    uint8_t pto_head = data_buf[0];
    uint8_t pto_tail = data_buf[num-1];
    // 验证帧头和帧尾 Verify frame header and footer
    if (!(pto_head == PTO_HEAD && pto_tail == PTO_TAIL)) {
        return;
    }

    uint8_t data_index = 1;
    uint8_t field_index[PTO_BUF_LEN_MAX] = {0};
    int i = 0;

    // 处理分隔符，将逗号替换为字符串结束符，记录字段位置
    // Process delimiters, replace commas with string terminators and record field positions
    for (i = 1; i < num-1; i++) {
        if (data_buf[i] == ',') {
            data_buf[i] = 0;
            field_index[data_index] = i;
            data_index++;
        }
    }

    // 处理无分隔符的情况，整个数据作为标签处理
    // Handle the case without delimiters, treat the entire data as a label
    if (data_index == 1) {
        uint8_t len = num - 2;
        memcpy(lubiao, (char*)data_buf+1, len);
        lubiao[len] = '\0';  // 确保字符串以'\0'结尾 Ensure the string ends with '\0'
    }
    else { // 处理多字段情况 Process multiple fields
        for (i = 0; i < data_index; i++) {
            uint8_t start = field_index[i] + 1;
            uint8_t len;
            
            if (i == data_index - 1) {
                // 最后一个字段，长度计算到帧尾前
                // Last field, length calculated up to before the frame footer
                len = (num - 1) - start;
            } else {
                // 中间字段，长度为下一个分隔符位置减去当前起始位置
                // Middle field, length is the next delimiter position minus the current start position
                len = field_index[i + 1] - start;
            }
            
            // 根据字段索引和总数处理不同类型的数据
            // Process different types of data based on field index and total count
            if (i == 6 && data_index == 7) {
                memcpy(msg, (char*)data_buf + start, len);
                msg[len] = '\0';  // 确保字符串以'\0'结尾 Ensure the string ends with '\0'
            }
            else if (i == 2 && data_index == 3) {
                memcpy(game, (char*)data_buf + start, len);
                game[len] = '\0';  // 确保字符串以'\0'结尾 Ensure the string ends with '\0'
            }
            else {
                // 其他字段转换为整数值
                // Convert other fields to integer values
                values[i] = Pto_Char_To_Int((char*)data_buf + start);
            }
        }
        
        // 帧长度验证，检查协议定义的长度与实际长度是否一致
        // Frame length verification, check if the protocol-defined length matches the actual length
        uint8_t pto_len = values[0];
        if (pto_len != num) {
            printf("pto_len error:%d , data_len:%d\n", pto_len, num);
            return;
        }

        // 提取协议ID Extract protocol ID
        pto_id = values[1];
    }

    // 提取坐标和尺寸信息 Extract coordinate and dimension information
    int x = values[2];
    int y = values[3];
    int w = values[4];
    int h = values[5];

    // 打印坐标和尺寸信息 Print coordinate and dimension information
    printf("dmcode:x:%d, y:%d, w:%d, h:%d,\n", x, y, w, h);

    // 打印游戏信息 Print game information
    printf("msg:%s\n", game);

    // 调试信息已注释 Debug information commented out
    // printf("game:%d\n", pto_id);
    // printf("msg:%s\n", msg);
}

• app_motor.c

x
/* @brief设置四个电机的速度
// speed_mX=[-1000, 1000], 单位为：mm/s
//speed_mX=[-1000,1000],Unit: mm/s
void Motion_Set_Speed(int16_t speed_m1, int16_t speed_m2, int16_t speed_m3, int16_t speed_m4)
{
    g_start_ctrl = 1;
    motor_data.speed_set[0] = speed_m1;
    motor_data.speed_set[1] = speed_m2;
    motor_data.speed_set[2] = speed_m3;
    motor_data.speed_set[3] = speed_m4;
    for (uint8_t i = 0; i < MAX_MOTOR; i++)
    {
        PID_Set_Motor_Target(i, motor_data.speed_set[i] * 1.0);
    }
}

5. Experimental phenomenon

After successfully downloading the program, take out a specific QR code and place it under the lens of the k230 visual module for recognition. After recognition, the car will make corresponding actions, and after completing the action, the car will stop.

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For program download, please refer to [Chapter 2: Development Environment Construction and Use → 2.6 Program Download and Simulation]

K230 Code Burning

Required tools: K230, SD card, CanMV IDE K230

We find the k230_track_recong.py file in the project folder, then drag it to CanMV IDE K230, and then choose to save the opened script as main.py to CanMV

The following is the QR code used in the tutorial:

goback

Goahead

turnleft

turnright