annotate touch.c @ 85:18b154c447bb

Add note about 1-wire wiring
author Daniel O'Connor <darius@dons.net.au>
date Thu, 12 Mar 2015 23:22:11 +1030
parents 58d76cf522ff
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
8
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
1 #include <stdint.h>
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
2
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
3 #include "stm32f10x.h"
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
4 #include "delay.h"
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
5 #include "spi.h"
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
6 #include "touch.h"
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
7
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
8 #define TP_SELECT() GPIO_ResetBits(GPIOB, GPIO_Pin_7)
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
9 #define TP_DESELECT() GPIO_SetBits(GPIOB, GPIO_Pin_7)
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
10
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
11 uint16_t
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
12 tp_read(uint8_t type) {
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
13 uint16_t x = 0;
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
14
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
15 /* Select device */
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
16 TP_SELECT();
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
17
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
18 /* Do conversion */
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
19 delay(10);
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
20 SPI_WriteByte(type);
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
21
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
22 /* Read result */
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
23 delay(10);
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
24 x = SPI_WriteByte(0x00);
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
25 x <<= 8;
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
26 x |= SPI_WriteByte(0x00);
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
27 delay(10);
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
28
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
29 /* De-select device */
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
30 TP_DESELECT();
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
31
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
32 /* Right justify 12 bit result */
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
33 x = x >> 3;
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
34 return (x);
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
35 }
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
36
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
37 void
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
38 tp_getcoords(uint16_t *x, uint16_t *y, uint16_t *z1, uint16_t *z2, float *t, float *t2) {
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
39 *x = tp_read(TP_READ_SEL(TP_CHAN_X, TP_MODE_12, TP_REF_DIFF, TP_PD_ON));
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
40 *y = tp_read(TP_READ_SEL(TP_CHAN_Y, TP_MODE_12, TP_REF_DIFF, TP_PD_ON));
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
41 *z1 = tp_read(TP_READ_SEL(TP_CHAN_Z1, TP_MODE_12, TP_REF_DIFF, TP_PD_ON));
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
42 *z2 = tp_read(TP_READ_SEL(TP_CHAN_Z2, TP_MODE_12, TP_REF_DIFF, TP_PD_ON));
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
43 *t = ((float)*x / 4096.0) * (((float)*z2 / (float)*z1) - 1);
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
44 *t2 = (((float)*x / 4096) * ((4096.0 / (float)*z1) - 1)) - (1 - ((float)*y / (float)4096.0));
58d76cf522ff Split out code into separate files.
Daniel O'Connor <darius@dons.net.au>
parents:
diff changeset
45 }