基于STM32F401RE开发板的X-NUCLEO-IKS01A3传感器测试之四LIS2MDL磁...

测试LIS2MDL磁力计花费了几天的时间，主要是在数据的显示时遇到了坑，从传感器返回的值是16位带符号的整数，开始我按二进制方式，大于32767的就按负数进行换算，但总是没有达到目的，折腾了许多才反映过来应该直接判断是否小于零，最后达到了目的，显示的结果与串口输出结果完全一致。下图是串口输出的测试结果：

    这是LCD显示的结果，显示分两个屏幕，第一屏显示轴向、自测前数据和自测数据。

    第二屏显示三个轴向的自测前后数据差和下限、上限：

    这是开机屏幕：

    现在还不清楚自测前后的数据表示什么，在测试中，如果开发不移动，每次测试返回的值都有少许差别，如果移动了位置则差别较大，目前仍在继续测试中，看能否弄清楚数值与位置或方向之间的规律。

    下面是添加了显示的代码：

• /**
•   * @brief  Performs LIS2MDL magnetometer self-test执行Lis2Mdl磁强计自检
•   * @retval BSP status
•   */
• static int32_t LIS2MDL_SelfTest(void)
• {
•   int32_t test_result = BSP_ERROR_NONE;
•   uint32_t i;
•   IKS01A3_MOTION_SENSOR_Axes_t data_nost;
•   IKS01A3_MOTION_SENSOR_Axes_t data_st;
•   IKS01A3_MOTION_SENSOR_Axes_t data;
•   uint8_t prev_reg_values[ST_REG_COUNT];
•   int32_t ret;
•        
•         int16_t temp;
•   (void)snprintf(dataOut, MAX_BUF_SIZE, "\r\nStarting LIS2MDL magnetometer self-test ...\r\nKeep the device still!!!\r\n");
•   printf("%s", dataOut);
•   HAL_Delay(INDICATION_DELAY);
•   BSP_LED_On(LED2);
•   /* Store current settings of the sensor 存储传感器的当前设置*/
•   for (i = 0; i < ST_REG_COUNT; i++)
•   {
•     if ((ret = IKS01A3_MOTION_SENSOR_Read_Register(IKS01A3_LIS2MDL_0, reg_addr, &prev_reg_values)) != BSP_ERROR_NONE)
•     {
•       return ret;
•     }
•   }
•   /* Set the sensor for self-test 设置传感器进行自检*/
•   for (i = 0; i < ST_REG_COUNT; i++)
•   {
•     if ((ret = IKS01A3_MOTION_SENSOR_Write_Register(IKS01A3_LIS2MDL_0, reg_addr, st_reg_values)) != BSP_ERROR_NONE)
•     {
•       return ret;
•     }
•   }
•   /* Wait defined time for stable output 等待确定的稳定输出时间*/
•   HAL_Delay(POWER_UP_DELAY);
•   /* Read first data and discard it 读取第一个数据并丢弃它*/
•   if (LIS2MDL_M_Get_Data(&data) != BSP_ERROR_NONE)
•   {
•     Error_Handler();
•   }
•   data_nost.x = 0;
•   data_nost.y = 0;
•   data_nost.z = 0;
•   /* Read valid data multiple times and average it 多次读取有效数据并取其平均值*/
•   for (i = 0; i < (uint32_t)N_SAMPLES; i++)
•   {
•     if (LIS2MDL_M_Get_Data(&data) != BSP_ERROR_NONE)
•     {
•       Error_Handler();
•     }
•     data_nost.x += data.x;
•     data_nost.y += data.y;
•     data_nost.z += data.z;
•   }
•   data_nost.x /= N_SAMPLES;
•   data_nost.y /= N_SAMPLES;
•   data_nost.z /= N_SAMPLES;
•   /* Enable self-test 启用自检*/
•   if ((ret = IKS01A3_MOTION_SENSOR_Set_SelfTest(IKS01A3_LIS2MDL_0, MOTION_MAGNETO, 1)) != BSP_ERROR_NONE)
•   {
•     return ret;
•   }
•   /* Wait defined time for stable output */
•   HAL_Delay(ST_ENABLED_DELAY);
•   /* Read first data and discard it 读取第一个数据并丢弃它*/
•   if (LIS2MDL_M_Get_Data(&data) != BSP_ERROR_NONE)
•   {
•     Error_Handler();
•   }
•   data_st.x = 0;
•   data_st.y = 0;
•   data_st.z = 0;
•   /* Read valid data multiple times and average it 多次读取有效数据并取其平均值*/
•   for (i = 0; i < (uint32_t)N_SAMPLES; i++)
•   {
•     if (LIS2MDL_M_Get_Data(&data) != BSP_ERROR_NONE)
•     {
•       Error_Handler();
•     }
•     data_st.x += data.x;
•     data_st.y += data.y;
•     data_st.z += data.z;
•   }
•   data_st.x /= N_SAMPLES;
•   data_st.y /= N_SAMPLES;
•   data_st.z /= N_SAMPLES;
•   /* Restore previous settings of the sensor 恢复传感器以前的设置*/
•   for (i = 0; i < ST_REG_COUNT; i++)
•   {
•     if ((ret = IKS01A3_MOTION_SENSOR_Write_Register(IKS01A3_LIS2MDL_0, reg_addr, prev_reg_values)) != BSP_ERROR_NONE)
•     {
•       return ret;
•     }
•   }
•   /* Evaluate the test 评估测试*/
•   if (abs(data_st.x - data_nost.x) < LO_LIM)
•   {
•     test_result = BSP_ERROR_COMPONENT_FAILURE;
•   }
•   if (abs(data_st.x - data_nost.x) > HI_LIM)
•   {
•     test_result = BSP_ERROR_COMPONENT_FAILURE;
•   }
•   if (abs(data_st.y - data_nost.y) < LO_LIM)
•   {
•     test_result = BSP_ERROR_COMPONENT_FAILURE;
•   }
•   if (abs(data_st.y - data_nost.y) > HI_LIM)
•   {
•     test_result = BSP_ERROR_COMPONENT_FAILURE;
•   }
•   if (abs(data_st.z - data_nost.z) < LO_LIM)
•   {
•     test_result = BSP_ERROR_COMPONENT_FAILURE;
•   }
•   if (abs(data_st.z - data_nost.z) > HI_LIM)
•   {
•     test_result = BSP_ERROR_COMPONENT_FAILURE;
•   }
•   /* Print measured data 打印测量数据*/
•   (void)snprintf(dataOut, MAX_BUF_SIZE, "\r\nMeasured magnetic field [mgauss]:\r\n");
•   //测量磁场: 轴,自测前,自测
•   printf("%s", dataOut);
•   (void)snprintf(dataOut, MAX_BUF_SIZE, "\r\n     AXIS     | PRE-SELFTEST |   SELFTEST\r\n");
•   printf("%s", dataOut);
•   (void)snprintf(dataOut, MAX_BUF_SIZE, "--------------|--------------|--------------\r\n");
•   printf("%s", dataOut);
•   (void)snprintf(dataOut, MAX_BUF_SIZE, "       X      | %8ld     | %8ld\r\n", data_nost.x, data_st.x);
•   printf("%s", dataOut);
•   (void)snprintf(dataOut, MAX_BUF_SIZE, "       Y      | %8ld     | %8ld\r\n", data_nost.y, data_st.y);
•   printf("%s", dataOut);
•   (void)snprintf(dataOut, MAX_BUF_SIZE, "       Z      | %8ld     | %8ld\r\n", data_nost.z, data_st.z);
•   printf("%s", dataOut);
•     //添加LCD显示的代码开始
•     LCD_clear();
•     LCD_write_BG(10,0,(uint8_t *)"磁场传感器");
•     LCD_write_ASCII(0,2,(uint8_t *)"PRE-SEL. SELF.");
•     LCD_write_ASCII(0,3,(uint8_t *)"X");
•     LCD_write_ASCII(0,4,(uint8_t *)"Y");
•     LCD_write_ASCII(0,5,(uint8_t *)"Z");
•         if(data_nost.x < 0){
•                 LCD_write_value(15,3,5,0,0,65536 - data_nost.x);
•                 LCD_write_ASCII(15,3,(uint8_t *)"-");
•         }
•         else
•         LCD_write_value(15,3,5,0,0,data_nost.x);
•         if(data_st.x < 0){
•                 LCD_write_value(50,3,5,0,0,65536 - data_st.x);
•                 LCD_write_ASCII(50,3,(uint8_t *)"-");
•         }
•         else       
•             LCD_write_value(50,3,5,0,0,data_st.x);
•        
•         if(data_nost.y < 0){
•                 LCD_write_value(15,4,5,0,0,65536 - data_nost.y);
•                 LCD_write_ASCII(15,4,(uint8_t *)"-");
•         }
•         else
•         LCD_write_value(15,4,5,0,0,data_nost.y);
•         if(data_st.y < 0){
•                 LCD_write_value(50,4,5,0,0,65536 - data_st.y);
•                 LCD_write_ASCII(50,4,(uint8_t *)"-");
•         }
•         else
•             LCD_write_value(50,4,5,0,0,data_st.y);
•         if(data_nost.z < 0){
•                 LCD_write_value(15,5,5,0,0,65536 - data_nost.z);
•                 LCD_write_ASCII(15,5,(uint8_t *)"-");
•         }
•         else
•         LCD_write_value(15,5,5,0,0,data_nost.z);
•        
•         if(data_st.z < 0){
•                 LCD_write_value(50,5,5,0,0,65536 - data_st.z);
•                 LCD_write_ASCII(50,5,(uint8_t *)"-");
•         }
•         else
•             LCD_write_value(50,5,5,0,0,data_st.z);
•        
•         //添加LCD显示的代码结束
•        
•   /* Print test limits and data 打印测试限值和数据*/
•   (void)snprintf(dataOut, MAX_BUF_SIZE, "\r\nTest limits and data [mgauss]:\r\n");
•   //试验限值和数据: 下限,差异,上限
•   printf("%s", dataOut);
•   (void)snprintf(dataOut, MAX_BUF_SIZE, "\r\n  LOW LIMIT   |  DIFFERENCE  |  HIGH LIMIT\r\n");
•   printf("%s", dataOut);
•   (void)snprintf(dataOut, MAX_BUF_SIZE, "--------------|--------------|--------------\r\n");
•   printf("%s", dataOut);
•   (void)snprintf(dataOut, MAX_BUF_SIZE, "%8d      | %8d     | %8d\r\n", LO_LIM, (int)abs(data_st.x - data_nost.x), HI_LIM);
•   printf("%s", dataOut);
•   (void)snprintf(dataOut, MAX_BUF_SIZE, "%8d      | %8d     | %8d\r\n", LO_LIM, (int)abs(data_st.y - data_nost.y), HI_LIM);
•   printf("%s", dataOut);
•   (void)snprintf(dataOut, MAX_BUF_SIZE, "%8d      | %8d     | %8d\r\n", LO_LIM, (int)abs(data_st.z - data_nost.z), HI_LIM);
•   printf("%s", dataOut);
•         //添加LCD显示的代码开始
•     HAL_Delay(8000);
•     LCD_clear();
•     LCD_write_BG(10,0,(uint8_t *)"磁场传感器");
•     LCD_write_ASCII(0,2,(uint8_t *)"LOW DIFF. HIGH");
•     LCD_write_value(0,3,2,0,0,LO_LIM);
•     temp = data_st.x - data_nost.x;
•         if(temp < 0){
•                 LCD_write_value(15,3,5,0,0,65536 - temp);
•                 LCD_write_ASCII(15,3,(uint8_t *)"-");
•         }
•         else
•         LCD_write_value(15,3,5,0,0,temp);
•         LCD_write_value(60,3,3,0,0,HI_LIM);
•        
•         LCD_write_value(0,4,2,0,0,LO_LIM);
•     temp = data_st.y - data_nost.y;
•         if(temp < 0){
•                 LCD_write_value(15,4,5,0,0,65536 - temp);
•                 LCD_write_ASCII(15,4,(uint8_t *)"-");
•         }
•         else
•         LCD_write_value(15,4,5,0,0,temp);
•         LCD_write_value(60,4,3,0,0,HI_LIM);
•        
•         LCD_write_value(0,5,2,0,0,LO_LIM);
•     temp = data_st.z - data_nost.z;
•         if(temp < 0){
•                 LCD_write_value(15,5,5,0,0,65536 - temp);
•                 LCD_write_ASCII(15,5,(uint8_t *)"-");
•         }
•         else
•         LCD_write_value(15,5,5,0,0,temp);
•         LCD_write_value(60,5,3,0,0,HI_LIM);
•        
•         //添加LCD显示的代码结束
•        
•   /* Print the test result */
•   if (test_result == BSP_ERROR_NONE)
•   {
•     (void)snprintf(dataOut, MAX_BUF_SIZE, "\r\nLIS2MDL magnetometer self-test PASSED!\r\n");
•   }
•   else
•   {
•     (void)snprintf(dataOut, MAX_BUF_SIZE, "\r\nLIS2MDL magnetometer self-test FAILED!\r\n");
•   }
•   printf("%s", dataOut);
•   BSP_LED_Off(LED2);
•   return ret;
• }
•