71 lines
2.4 KiB
C
71 lines
2.4 KiB
C
/* vim: set ai et ts=4 sw=4: */
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#include "../Src/ili9341_touch.h"
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#include "stm32f4xx_hal.h"
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#define READ_X 0xD0
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#define READ_Y 0x90
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static void ILI9341_TouchSelect() {
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HAL_GPIO_WritePin(ILI9341_TOUCH_CS_GPIO_Port, ILI9341_TOUCH_CS_Pin, GPIO_PIN_RESET);
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}
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void ILI9341_TouchUnselect() {
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HAL_GPIO_WritePin(ILI9341_TOUCH_CS_GPIO_Port, ILI9341_TOUCH_CS_Pin, GPIO_PIN_SET);
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}
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bool ILI9341_TouchPressed() {
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return HAL_GPIO_ReadPin(ILI9341_TOUCH_IRQ_GPIO_Port, ILI9341_TOUCH_IRQ_Pin) == GPIO_PIN_RESET;
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}
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bool ILI9341_TouchGetCoordinates(uint16_t* x, uint16_t* y) {
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static const uint8_t cmd_read_x[] = { READ_X };
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static const uint8_t cmd_read_y[] = { READ_Y };
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static const uint8_t zeroes_tx[] = { 0x00, 0x00 };
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ILI9341_TouchSelect();
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uint32_t avg_x = 0;
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uint32_t avg_y = 0;
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uint8_t nsamples = 0;
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for(uint8_t i = 0; i < 16; i++) {
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if(!ILI9341_TouchPressed())
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break;
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nsamples++;
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HAL_SPI_Transmit(&ILI9341_TOUCH_SPI_PORT, (uint8_t*)cmd_read_y, sizeof(cmd_read_y), HAL_MAX_DELAY);
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uint8_t y_raw[2];
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HAL_SPI_TransmitReceive(&ILI9341_TOUCH_SPI_PORT, (uint8_t*)zeroes_tx, y_raw, sizeof(y_raw), HAL_MAX_DELAY);
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HAL_SPI_Transmit(&ILI9341_TOUCH_SPI_PORT, (uint8_t*)cmd_read_x, sizeof(cmd_read_x), HAL_MAX_DELAY);
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uint8_t x_raw[2];
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HAL_SPI_TransmitReceive(&ILI9341_TOUCH_SPI_PORT, (uint8_t*)zeroes_tx, x_raw, sizeof(x_raw), HAL_MAX_DELAY);
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avg_x += (((uint16_t)x_raw[0]) << 8) | ((uint16_t)x_raw[1]);
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avg_y += (((uint16_t)y_raw[0]) << 8) | ((uint16_t)y_raw[1]);
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}
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ILI9341_TouchUnselect();
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if(nsamples < 16)
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return false;
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uint32_t raw_x = (avg_x / 16);
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if(raw_x < ILI9341_TOUCH_MIN_RAW_X) raw_x = ILI9341_TOUCH_MIN_RAW_X;
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if(raw_x > ILI9341_TOUCH_MAX_RAW_X) raw_x = ILI9341_TOUCH_MAX_RAW_X;
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uint32_t raw_y = (avg_y / 16);
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if(raw_y < ILI9341_TOUCH_MIN_RAW_Y) raw_y = ILI9341_TOUCH_MIN_RAW_Y;
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if(raw_y > ILI9341_TOUCH_MAX_RAW_Y) raw_y = ILI9341_TOUCH_MAX_RAW_Y;
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// Uncomment this line to calibrate touchscreen:
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// UART_Printf("raw_x = %d, raw_y = %d\r\n", x, y);
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*x = (raw_x - ILI9341_TOUCH_MIN_RAW_X) * ILI9341_TOUCH_SCALE_X / (ILI9341_TOUCH_MAX_RAW_X - ILI9341_TOUCH_MIN_RAW_X);
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*y = (raw_y - ILI9341_TOUCH_MIN_RAW_Y) * ILI9341_TOUCH_SCALE_Y / (ILI9341_TOUCH_MAX_RAW_Y - ILI9341_TOUCH_MIN_RAW_Y);
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return true;
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}
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