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discoverpixy/discovery/src/ll_touch.c

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9.3 KiB
C
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#include"ll_touch.h"
#include<stm32f4xx_spi.h>
#include<stm32f4xx_rcc.h>
#include<stm32f4xx_exti.h>
#include<stm32f4xx_syscfg.h>
#include<tft.h>
#include<touch.h>
#include<stdio.h>
#include<stdlib.h>
/* Defines ---------------------------------------------------------- */
#define CLEAR_CS GPIO_ResetBits(GPIOB,GPIO_Pin_9)
#define SET_CS GPIO_SetBits(GPIOB,GPIO_Pin_9)
#define REQ_X_COORD 0x90 // Request x coordinate
#define REQ_Y_COORD 0xD0 // Request y coordinate
#define REQ_1_DATAB 0x00 // Request one databyte
#define DWIDTH 320
#define DHEIGHT 240
#define CCENTER 20
#define x1 0x0231
#define dx 0x0C08
#define y1 0x0287
#define dy 0x0B56
#define NSAMPLE 16
/* Globals ----------------------------------------------------------- */
volatile bool pen_state = false; // PenDown = True; PenUp = False;
volatile bool tim_flag = false;
volatile uint16_t x_samples[NSAMPLE-1];
volatile uint16_t y_samples[NSAMPLE-1];
volatile int i;
/* Prototypes -------------------------------------------------------- */
bool ll_touch_init();
static void init_exti();
static void init_timer();
static uint8_t touch_send(uint8_t dat);
static uint16_t avg_vals(uint16_t samples[], uint16_t len);
static uint16_t touch_get_y_coord();
static uint16_t touch_get_y_coord();
void touch_test(uint16_t x, uint16_t y);
/* Functions --------------------------------------------------------- */
static uint16_t avg_vals(uint16_t samples[], uint16_t len)
{
uint16_t j = 0;
uint32_t tmp = 0;
for(j = 0; j < len; j++){
tmp += samples[j];
}
return (uint16_t)(tmp/len);
}
static uint16_t touch_get_x_coord()
{
uint16_t buf_x = 0;
CLEAR_CS; // clear chipselect
touch_send(REQ_X_COORD); // request x coordinate
buf_x = ((uint16_t) touch_send(REQ_1_DATAB)) << 5;
buf_x |= touch_send(REQ_1_DATAB) >> 3;
SET_CS; // set chipselect
return buf_x;
}
static uint16_t touch_get_y_coord()
{
uint16_t buf_y = 0;
CLEAR_CS; // clear chipselect
touch_send(REQ_Y_COORD); // request y coordinate
buf_y = ((uint16_t) touch_send(REQ_1_DATAB)) << 5;
buf_y |= touch_send(REQ_1_DATAB) >> 3;
SET_CS; // set chipselect
return buf_y;
}
static uint8_t touch_send(uint8_t dat)
{
SPI_I2S_SendData(SPI2, dat);
while(SPI_I2S_GetFlagStatus(SPI2, SPI_I2S_FLAG_BSY) != RESET);
while(SPI_I2S_GetFlagStatus(SPI2, SPI_I2S_FLAG_RXNE) == RESET);
return SPI_I2S_ReceiveData(SPI2);
}
void touch_test(uint16_t x, uint16_t y)
{
char xs[10];
char ys[10];
tft_clear(BLACK);
itoa(x, xs, 10);
itoa(y, ys, 10);
tft_print_line(10, 10, WHITE, TRANSPARENT, 0, (const char*)xs);
tft_print_line(10, 30, WHITE, TRANSPARENT, 0, (const char*)ys);
}
bool ll_touch_init()
{
//We have a ADS7843 Touch controller
//Datasheet: http://www.ti.com/lit/ds/symlink/ads7843.pdf
/* init structures */
SPI_InitTypeDef SPI_SPI2_InitStructure;
GPIO_InitTypeDef GPIO_SPI2_InitStructure;
RCC_APB2PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE); // enable clock on gpiob
RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE); // ebable spi clock
/* fill gpio init struct and init gpio */
GPIO_StructInit(&GPIO_SPI2_InitStructure);
GPIO_SPI2_InitStructure.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_14 | GPIO_Pin_15; // 10 = SPI2_SCK, 14 = SPI2_MISO, 15 = SPI2_MOSI
GPIO_SPI2_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_SPI2_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_SPI2_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_SPI2_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOB, &GPIO_SPI2_InitStructure);
SET_CS; // set chip select
/* fill gpio init struct and init gpio */
GPIO_StructInit(&GPIO_SPI2_InitStructure);
GPIO_SPI2_InitStructure.GPIO_Pin = GPIO_Pin_9; // 9 = SPI2_CS
GPIO_SPI2_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_SPI2_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_SPI2_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_SPI2_InitStructure);
/* init alternate functions on GPIOB */
GPIO_PinAFConfig(GPIOB, GPIO_PinSource10, GPIO_AF_SPI2);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource14, GPIO_AF_SPI2);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource15, GPIO_AF_SPI2);
SPI_I2S_DeInit(SPI2); // Clear spi initialisation
/* fill spi init structure */
SPI_StructInit(&SPI_SPI2_InitStructure);
SPI_SPI2_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
SPI_SPI2_InitStructure.SPI_Mode = SPI_Mode_Master;
SPI_SPI2_InitStructure.SPI_DataSize = SPI_DataSize_8b;
SPI_SPI2_InitStructure.SPI_CPOL = SPI_CPOL_Low;
SPI_SPI2_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;
SPI_SPI2_InitStructure.SPI_NSS = SPI_NSS_Soft | SPI_NSSInternalSoft_Set;
SPI_SPI2_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256;
SPI_SPI2_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
SPI_Init(SPI2, &SPI_SPI2_InitStructure); // init spi
SPI_Cmd(SPI2, ENABLE); // enable spi
init_exti(); // init external interrupt for penirq
init_timer(); // init the timer 6 for sampling x and y coordinates
return true;
}
static void init_exti()
{
/* init structures */
GPIO_InitTypeDef gpio;
EXTI_InitTypeDef exti;
NVIC_InitTypeDef nvic;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE); // enable GPIOA clock
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE); // enable SYSCFG clock
/* Set GPIOA0 as input */
gpio.GPIO_Mode = GPIO_Mode_IN;
gpio.GPIO_OType = GPIO_OType_PP;
gpio.GPIO_Pin = GPIO_Pin_0;
gpio.GPIO_PuPd = GPIO_PuPd_UP;
gpio.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_Init(GPIOA, &gpio);
SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOA, EXTI_PinSource0); // Bind Exti_line0 to PA0
/* EXTI on PA0 */
EXTI_StructInit(&exti);
exti.EXTI_Line = EXTI_Line0;
exti.EXTI_Mode = EXTI_Mode_Interrupt;
exti.EXTI_Trigger = EXTI_Trigger_Rising_Falling;
exti.EXTI_LineCmd = ENABLE;
EXTI_Init(&exti);
/* Add IRQ vector to NVIC */
nvic.NVIC_IRQChannel = EXTI0_IRQn; // PD0 -> EXTI_Line0 -> EXTI0_IRQn vector
nvic.NVIC_IRQChannelPreemptionPriority = 0x00; // Set priority
nvic.NVIC_IRQChannelSubPriority = 0x00; // Set sub priority
nvic.NVIC_IRQChannelCmd = ENABLE; // Enable interrupt
NVIC_Init(&nvic); // Config NVIC
}
static void init_timer()
{
TIM_TimeBaseInitTypeDef t;
const int APB1_CLK = 42E6;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM7, ENABLE); // Enable clock for TIM6
/* Timer 7 configuration */
TIM_TimeBaseStructInit(&t); // Init TimeBaseStruct
t.TIM_Prescaler = APB1_CLK / 1000 - 1; // 0..41999 prescaler
t.TIM_Period = 20- 1; // 10ms cycle time
TIM_TimeBaseInit(TIM7, &t); // Init TIM7
TIM_ITConfig(TIM7, TIM_IT_Update, ENABLE); // Enable update IRQ for TIM7
NVIC_EnableIRQ(TIM7_IRQn); // Enable IRQs for TIM7
}
/* Interrupt service routines ------------------------------------------ */
void EXTI0_IRQHandler()
{
if (EXTI_GetITStatus(EXTI_Line0) == SET) { // Make sure the interrupt flag is set
if(!pen_state){ // Check if PENDOWN or PENUP
TIM_Cmd(TIM7, ENABLE); // Start the timer
while(!tim_flag); // Wait for the sampling to finish
touch_add_raw_event(avg_vals(x_samples, NSAMPLE), avg_vals(y_samples, NSAMPLE), TOUCH_DOWN);
}else{
TIM_Cmd(TIM7, ENABLE); // Start the timer
while(!tim_flag); // Wait for the sampling to finish
touch_add_raw_event(avg_vals(x_samples, NSAMPLE), avg_vals(y_samples, NSAMPLE), TOUCH_UP);
}
pen_state = !pen_state; // Toggle penstate
tim_flag = false; // Clear timer flag
EXTI_ClearITPendingBit(EXTI_Line0); // Clear interrupt flag
}
}
void TIM7_IRQHandler()
{
if(TIM_GetFlagStatus(TIM7, TIM_IT_Update) == SET){ // Make sure the interrupt flag is set
for(i = 0; i < (NSAMPLE-1); i++){
/* get x and y coordinate and apply calibration */
x_samples[i] = (((long)(DWIDTH-2*CCENTER)*2*(long)((long)touch_get_x_coord()-x1)/dx+1)>>1)+CCENTER;
y_samples[i] = (((long)(DHEIGHT-2*CCENTER)*2*(long)((long)touch_get_y_coord()-y1)/dy+1)>>1)+CCENTER;
}
tim_flag = true; // Set the global timer flag
TIM_Cmd(TIM7, DISABLE); // Count only once
}
}
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