其实道理很简单，就是用adc读电压，但细节很多。废话不说，直接上代码，这是给的STemWin驱动，但原理是。如果单独使用，则需要滤波。
第一个细节： 浮空引脚需要内部下拉，否则无法判断是否按压。
第二个细节：ADC的sampling时间不宜过小，否则读数不稳定，无法使用。
#include "GUI.h" #define XSIZE_PHYS 240 // To be adapted to x-screen size #define YSIZE_PHYS 320 // To be adapted to y-screen size #define GUI_TOUCH_AD_TOP 3600 #define GUI_TOUCH_AD_BOTTOM 410 #define GUI_TOUCH_AD_LEFT 410 #define GUI_TOUCH_AD_RIGHT 3660 void GUI_TOUCH_X_Init(void) { GUI_TOUCH_SetOrientation(GUI_SWAP_XY); GUI_TOUCH_Calibrate(GUI_COORD_X, 0, XSIZE_PHYS, GUI_TOUCH_AD_LEFT, GUI_TOUCH_AD_RIGHT); GUI_TOUCH_Calibrate(GUI_COORD_Y, 0, YSIZE_PHYS, GUI_TOUCH_AD_TOP, GUI_TOUCH_AD_BOTTOM); } void GUI_TOUCH_X_ActivateX(void) { GPIO_InitTypeDef GPIO_InitStruct = {0}; // X- = 0 GPIO_InitStruct.Pin = X_Left_Pin; GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP; GPIO_InitStruct.Pull = GPIO_NOPULL; GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW; HAL_GPIO_Init(X_Left_GPIO_Port, &GPIO_InitStruct); HAL_GPIO_WritePin(X_Left_GPIO_Port, X_Left_Pin, GPIO_PIN_RESET); // X = 1 GPIO_InitStruct.Pin = X_RIGHT_Pin; GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP; GPIO_InitStruct.Pull = GPIO_NOPULL; GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW; HAL_GPIO_Init(X_RIGHT_GPIO_Port, &GPIO_InitStruct); HAL_GPIO_WritePin(X_RIGHT_GPIO_Port, X_RIGHT_Pin, GPIO_PIN_SET); // Enable Y- = NO PULLUP OR DOWN GPIO_InitStruct.Pin = Y_UP_Pin; GPIO_InitStruct.Mode = GPIO_MODE_INPUT; GPIO_InitStruct.Pull = GPIO_PULLDOWN; HAL_GPIO_Init(Y_UP_GPIO_Port, &GPIO_InitStruct); // Enable Y ADC, Channel 3 GPIO_InitStruct.Pin = Y_DOWN_Pin; GPIO_InitStruct.Mode = GPIO_MODE_ANALOG; GPIO_InitStruct.Pull = GPIO_NOPULL; HAL_GPIO_Init(Y_DOWN_GPIO_Port, &GPIO_InitStruct); } void GUI_TOUCH_X_ActivateY(void) { GPIO_InitTypeDef GPIO_InitStruct = {0}; // Y- = 0 GPIO_InitStruct.Pin = Y_UP_Pin; GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP; GPIO_InitStruct.Pull = GPIO_NOPULL; GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW; HAL_GPIO_Init(Y_UP_GPIO_Port, &GPIO_InitStruct); HAL_GPIO_WritePin(Y_UP_GPIO_Port, Y_UP_Pin, GPIO_PIN_RESET); // Y = 1 GPIO_InitStruct.Pin = Y_DOWN_Pin; GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP; GPIO_InitStruct.Pull = GPIO_NOPULL; GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW; HAL_GPIO_Init(Y_DOWN_GPIO_Port, &GPIO_InitStruct); HAL_GPIO_WritePin(Y_DOWN_GPIO_Port, Y_DOWN_Pin, GPIO_PIN_SET); // X- NO PULL UP or DOWN GPIO_InitStruct.Pin = X_Left_Pin; GPIO_InitStruct.Mode = GPIO_MODE_INPUT; GPIO_InitStruct.Pull = GPIO_PULLDOWN; HAL_GPIO_Init(X_Left_GPIO_Port, &GPIO_InitStruct); // Enable X ADC, Channel 2 GPIO_InitStruct.Pin = X_RIGHT_Pin; GPIO_InitStruct.Mode = GPIO_MODE_ANALOG; GPIO_InitStruct.Pull = GPIO_NOPULL; HAL_GPIO_Init(X_RIGHT_GPIO_Port, &GPIO_InitStruct); } int GUI_TOUCH_X_MeasureX(void) { int result; ADC_ChannelConfTypeDef sConfig = {0}; /* * Configure for the selected ADC regular channel its corresponding rank in the sequencer and its sample time. */ sConfig.Channel = ADC_CHANNEL_2; sConfig.Rank = 1; sConfig.SamplingTime = ADC_SAMPLETIME_480CYCLES; if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK) { Error_Handler(); } if (HAL_ADC_Start(&hadc1) != HAL_OK) { Error_Handler(); } if (HAL_ADC_PollForConversion(&hadc1, 10) != HAL_OK) { Error_Handler(); } result = HAL_ADC_GetValue(&hadc1); if (HAL_ADC_Stop(&hadc1) != HAL_OK) { Error_Handler(); } return result; } int GUI_TOUCH_X_MeasureY(void) { int result; ADC_ChannelConfTypeDef sConfig = {0}; /* * Configure for the selected ADC regular channel its corresponding rank in the sequencer and its sample time. */ sConfig.Channel = ADC_CHANNEL_3; sConfig.Rank = 1; sConfig.SamplingTime = ADC_SAMPLETIME_480CYCLES; if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK) { Error_Handler(); } if (HAL_ADC_Start(&hadc1) != HAL_OK) { Error_Handler(); } if (HAL_ADC_PollForConversion(&hadc1, 10) != HAL_OK) { Error_Handler(); } result = HAL_ADC_GetValue(&hadc1); if (HAL_ADC_Stop(&hadc1) != HAL_OK) { Error_Handler(); } return result; }