仔细分析这一段 /* initialize touch number and corrdinate */ *(p_instance_ctrl->pinfo.p_num_touch) = 0; *(p_instance_ctrl->pinfo.p_rx_coordinate) = TOUCH_OFF_VALUE; *(p_instance_ctrl->pinfo.p_tx_coordinate) = TOUCH_OFF_VALUE; /* Get local variable (TS number & data pinch) */ num_x = p_instance_ctrl->p_touch_cfg->p_ctsu_instance->p_cfg->num_rx; TOUCH_ERROR_RETURN(0 != num_x, FSP_ERR_ASSERTION); num_y = p_instance_ctrl->p_touch_cfg->p_ctsu_instance->p_cfg->num_tx; TOUCH_ERROR_RETURN(0 != num_y, FSP_ERR_ASSERTION); element_num = (uint16_t) (num_x * num_y); /* Data get */ err = p_instance_ctrl->p_ctsu_instance->p_api->dataGet(p_instance_ctrl->p_ctsu_instance->p_ctrl, g_touch_pad_buf); FSP_ERROR_RETURN(FSP_ERR_CTSU_SCANNING != err, FSP_ERR_CTSU_SCANNING); /* check for max touch */ if (*(p_instance_ctrl->pinfo.p_max_touch) > TOUCH_PAD_MONITOR_TOUCH_NUM_MAX) { max_touch = TOUCH_PAD_MONITOR_TOUCH_NUM_MAX; } else { max_touch = *(p_instance_ctrl->pinfo.p_max_touch); } /* make difference value = secondary - primary */ for (i = 0; i < element_num; i++) { /* save to buffer in the first half */ g_touch_pad_buf[i] = (uint16_t) (g_touch_pad_buf[(i * 2) + 1] - g_touch_pad_buf[i * 2]); }

这段代码是在初始化触摸板相关的变量和获取触摸数据。首先，它将触摸数和坐标值初始化为0和TOUCH_OFF_VALUE。然后，它从触摸板配置结构体中获取接收和发送通道的数量，并计算出元素数量。接下来，它调用dataGet函数来获取触摸数据，并将数据存储在g_touch_pad_buf数组中。如果获取数据时发现触摸板正在扫描，则返回FSP_ERR_CTSU_SCANNING错误。然后，它检查最大触摸数是否超过了最大值，如果超过了，则将最大触摸数设置为最大值，否则将最大触摸数设置为p_max_touch指针所指向的值。最后，它对每个元素进行处理，将其次级值减去主级值，并将结果保存在g_touch_pad_buf数组的前一半中。这个程序的目的是为了监控触摸板上的触摸情况，并将数据处理成差分形式方便后续使用。

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/* Initialize FSM */ next_state = STATE_MAIN_MENU; state = !STATE_MAIN_MENU;

这段代码是用来初始化有限状态机的。

`next_state`被赋值为`STATE_MAIN_MENU`，表示有限状态机的下一个状态是主菜单状态。

`state`被赋值为`!STATE_MAIN_MENU`，表示有限状态机的当前状态是不是主菜单状态。因为`!`取反运算符会将非0值变成0，将0值变成1，所以这里的意图是将当前状态初始化为一个非主菜单状态。

需要注意的是，这段代码只是有限状态机的初始化操作，具体的状态转移逻辑和实现需要在后续的代码中实现。

这个函数怎么使用HAL_StatusTypeDef HAL_UART_Init(UART_HandleTypeDef *huart) { /* Check the UART handle allocation */ if (huart == NULL) { return HAL_ERROR; } /* Check the parameters */ if (huart->Init.HwFlowCtl != UART_HWCONTROL_NONE) { /* The hardware flow control is available only for USART1, USART2, USART3 and USART6. Except for STM32F446xx devices, that is available for USART1, USART2, USART3, USART6, UART4 and UART5. */ assert_param(IS_UART_HWFLOW_INSTANCE(huart->Instance)); assert_param(IS_UART_HARDWARE_FLOW_CONTROL(huart->Init.HwFlowCtl)); } else { assert_param(IS_UART_INSTANCE(huart->Instance)); } assert_param(IS_UART_WORD_LENGTH(huart->Init.WordLength)); assert_param(IS_UART_OVERSAMPLING(huart->Init.OverSampling)); if (huart->gState == HAL_UART_STATE_RESET) { /* Allocate lock resource and initialize it */ huart->Lock = HAL_UNLOCKED; #if (USE_HAL_UART_REGISTER_CALLBACKS == 1) UART_InitCallbacksToDefault(huart); if (huart->MspInitCallback == NULL) { huart->MspInitCallback = HAL_UART_MspInit; } /* Init the low level hardware */ huart->MspInitCallback(huart); #else /* Init the low level hardware : GPIO, CLOCK */ HAL_UART_MspInit(huart); #endif /* (USE_HAL_UART_REGISTER_CALLBACKS) */ } huart->gState = HAL_UART_STATE_BUSY; /* Disable the peripheral */ __HAL_UART_DISABLE(huart); /* Set the UART Communication parameters */ UART_SetConfig(huart); /* In asynchronous mode, the following bits must be kept cleared: - LINEN and CLKEN bits in the USART_CR2 register, - SCEN, HDSEL and IREN bits in the USART_CR3 register.*/ CLEAR_BIT(huart->Instance->CR2, (USART_CR2_LINEN | USART_CR2_CLKEN)); CLEAR_BIT(huart->Instance->CR3, (USART_CR3_SCEN | USART_CR3_HDSEL | USART_CR3_IREN)); /* Enable the peripheral */ __HAL_UART_ENABLE(huart); /* Initialize the UART state */ huart->ErrorCode = HAL_UART_ERROR_NONE; huart->gState = HAL_UART_STATE_READY; huart->RxState = HAL_UART_STATE_READY; return HAL_OK; }

这个函数是HAL库（STM32的驱动库）中的UART初始化函数，用于初始化指定的UART外设。它的参数是一个UART_HandleTypeDef类型的指针，其中包含了UART的初始化参数和外设的实例。函数执行过程中会进行一系列的参数检查，包括检查参数是否为空、硬件流控制是否可用、数据位长度是否合法等等。如果UART的gState状态为HAL_UART_STATE_RESET，那么它会先初始化底层硬件资源（包括GPIO和时钟），否则会直接进行配置和使能。最后，函数会将UART的状态设置为HAL_UART_STATE_READY，表示初始化完成。