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Implemented basic sampling and averaging of touch coordinates using timer7

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This commit is contained in:
id101010
2015-05-29 01:34:55 +02:00
parent 1785b80dc4
commit 7d2d1a13e4
4 changed files with 79 additions and 24 deletions
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4
discovery/.gitignore vendored
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@@ -4,3 +4,7 @@ obj/
libs/*/obj
libs/*/*.a
libs/*/*.o
*~
*.swp
*.swo

90
discovery/src/ll_touch.c
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@@ -14,19 +14,45 @@
#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 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();
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;
@@ -64,16 +90,12 @@ static uint8_t touch_send(uint8_t dat)
return SPI_I2S_ReceiveData(SPI2);
}
void touch_test()
void touch_test(uint16_t x, uint16_t y)
{
uint16_t x = 0, y = 0;
char xs[10];
char ys[10];
tft_clear(BLACK);
x = touch_get_x_coord();
y = touch_get_y_coord();
itoa(x, xs, 10);
itoa(y, ys, 10);
@@ -135,9 +157,11 @@ bool ll_touch_init()
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 */
@@ -174,26 +198,54 @@ static void init_exti()
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) != RESET) { // Make sure the interrupt flag is set
touch_test();
if (EXTI_GetITStatus(EXTI_Line0) == SET) { // Make sure the interrupt flag is set
//uint16_t x = touch_get_x_coord();
//uint16_t y = touch_get_y_coord();
uint16_t x = 0;
uint16_t y = 0;
if(pen_state){
touch_add_raw_event(x, y, TOUCH_DOWN);
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{
touch_add_raw_event(x, y, TOUCH_UP);
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
}
}