82 lines
2.2 KiB
C
82 lines
2.2 KiB
C
#include STM32_HAL_H
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#include <string.h>
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#include "touch.h"
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I2C_HandleTypeDef i2c_handle = {
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.Instance = I2C1,
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};
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int touch_init(void) {
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// Enable I2C clock
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__HAL_RCC_I2C1_CLK_ENABLE();
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// Init SCL and SDA GPIO lines (PB6 & PB7)
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GPIO_InitTypeDef GPIO_InitStructure = {
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.Pin = GPIO_PIN_6 | GPIO_PIN_7,
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.Mode = GPIO_MODE_AF_OD,
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.Pull = GPIO_NOPULL,
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.Speed = GPIO_SPEED_FREQ_VERY_HIGH,
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.Alternate = GPIO_AF4_I2C1,
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};
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HAL_GPIO_Init(GPIOB, &GPIO_InitStructure);
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I2C_InitTypeDef *init = &(i2c_handle.Init);
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init->OwnAddress1 = 0xFE; // master
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init->ClockSpeed = 400000;
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init->DutyCycle = I2C_DUTYCYCLE_16_9;
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init->AddressingMode = I2C_ADDRESSINGMODE_7BIT;
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init->DualAddressMode = I2C_DUALADDRESS_DISABLE;
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init->GeneralCallMode = I2C_GENERALCALL_DISABLE;
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init->NoStretchMode = I2C_NOSTRETCH_DISABLE;
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init->OwnAddress2 = 0;
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// Init I2C handle
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if (HAL_I2C_Init(&i2c_handle) != HAL_OK) {
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return 1;
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}
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// Enable IRQs
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HAL_NVIC_EnableIRQ(I2C1_EV_IRQn);
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HAL_NVIC_EnableIRQ(I2C1_ER_IRQn);
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return 0;
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}
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#define TOUCH_ADDRESS 56
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#define TOUCH_PACKET_SIZE 16
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uint32_t touch_read(void) {
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static uint8_t data[TOUCH_PACKET_SIZE], old_data[TOUCH_PACKET_SIZE];
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if (HAL_OK != HAL_I2C_Master_Receive(&i2c_handle, TOUCH_ADDRESS << 1, data, TOUCH_PACKET_SIZE, 1)) {
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return 0; // read failure
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}
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if (0 == memcmp(data, old_data, TOUCH_PACKET_SIZE)) {
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return 0; // no new event
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}
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memcpy(old_data, data, TOUCH_PACKET_SIZE);
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if (data[0] == 0xff && data[1] == 0x00) {
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if (data[2] == 0x01 && data[3] == 0x00) {
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return TOUCH_START | (data[4] << 8) | data[6]; // touch start
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} else
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if (data[2] == 0x01 && data[3] == 0x80) {
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return TOUCH_MOVE | (data[4] << 8) | data[6]; // touch move
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} else
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if (data[2] == 0x00 && data[3] == 0x40) {
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return TOUCH_END | (data[4] << 8) | data[6]; // touch end
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}
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}
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return 0;
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}
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void I2C1_EV_IRQHandler(void) {
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HAL_I2C_EV_IRQHandler(&i2c_handle);
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}
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void I2C1_ER_IRQHandler(void) {
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HAL_I2C_ER_IRQHandler(&i2c_handle);
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}
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