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comparison touch.c @ 8:58d76cf522ff

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Split out code into separate files.
author Daniel O'Connor <darius@dons.net.au>
date Sat, 04 Feb 2012 13:29:31 +1030
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7:9404b9869c27 8:58d76cf522ff
1 #include <stdint.h>
2
3 #include "stm32f10x.h"
4 #include "delay.h"
5 #include "spi.h"
6 #include "touch.h"
7
8 #define TP_SELECT() GPIO_ResetBits(GPIOB, GPIO_Pin_7)
9 #define TP_DESELECT() GPIO_SetBits(GPIOB, GPIO_Pin_7)
10
11 uint16_t
12 tp_read(uint8_t type) {
13 uint16_t x = 0;
14
15 /* Select device */
16 TP_SELECT();
17
18 /* Do conversion */
19 delay(10);
20 SPI_WriteByte(type);
21
22 /* Read result */
23 delay(10);
24 x = SPI_WriteByte(0x00);
25 x <<= 8;
26 x |= SPI_WriteByte(0x00);
27 delay(10);
28
29 /* De-select device */
30 TP_DESELECT();
31
32 /* Right justify 12 bit result */
33 x = x >> 3;
34 return (x);
35 }
36
37 void
38 tp_getcoords(uint16_t *x, uint16_t *y, uint16_t *z1, uint16_t *z2, float *t, float *t2) {
39 *x = tp_read(TP_READ_SEL(TP_CHAN_X, TP_MODE_12, TP_REF_DIFF, TP_PD_ON));
40 *y = tp_read(TP_READ_SEL(TP_CHAN_Y, TP_MODE_12, TP_REF_DIFF, TP_PD_ON));
41 *z1 = tp_read(TP_READ_SEL(TP_CHAN_Z1, TP_MODE_12, TP_REF_DIFF, TP_PD_ON));
42 *z2 = tp_read(TP_READ_SEL(TP_CHAN_Z2, TP_MODE_12, TP_REF_DIFF, TP_PD_ON));
43 *t = ((float)*x / 4096.0) * (((float)*z2 / (float)*z1) - 1);
44 *t2 = (((float)*x / 4096) * ((4096.0 / (float)*z1) - 1)) - (1 - ((float)*y / (float)4096.0));
45 }