WebSVN – DashDisplay – Blame – /trunk/Src/switches.c

Rev	Author	Line No.	Line
2	mjames	1	#include "stm32f1xx_hal.h"
		2
		3	#include "switches.h"
		4
		5
		6	typedef enum {
		7	PH_00 = 0, PH_10 = 2, PH_11 = 3, PH_01 = 1,
		8	} eGreyCode;
		9
		10	typedef struct {
		11	GPIO_TypeDef * GPIO;
		12	uint16_t Pin;
		13	} sGPIOPin;
		14
		15	volatile int dial_pos[MAX_DIALS];
		16	volatile int dial_last[MAX_DIALS]; // previous debounced switch position
		17
		18	volatile int push_pos[MAX_PUSHBUTTONS];
		19
		20	volatile static int sw_newstate[MAX_SWITCHES]; //< debounced switch state
		21	volatile static int sw_count[MAX_SWITCHES]; //< debounce counter
		22
		23	static const sGPIOPin sw_arr[MAX_SWITCHES] =
		24	{ { SW1_I_GPIO_Port, SW1_I_Pin }, // these two pins used to encode SW1 phase
		25	{ SW1_Q_GPIO_Port, SW1_Q_Pin }, // " SW1 phase
		26	{ SW2_I_GPIO_Port, SW2_I_Pin }, // these two pins used to encode SW2 phase
		27	{ SW2_Q_GPIO_Port, SW2_Q_Pin }, // " SW2 phase
		28	{ SW1_PUSH_GPIO_Port, SW1_PUSH_Pin }, // two debounced switches
		29	{ SW2_PUSH_GPIO_Port, SW2_PUSH_Pin }, };
		30
		31	// call this to setup switch states
		32	void InitSwitches(void) {
		33	int i;
		34
		35	for (i = 0; i < MAX_SWITCHES; i++) {
		36	sw_newstate[i] = 0;
		37	sw_count[i] = 0;
		38	}
		39
		40	// reset the dial positions
		41	dial_pos[0] = 0;
4	mjames	42	dial_pos[1] = 0;
2	mjames	43	}
		44
4	mjames	45	// this gray encodes the dial , but you cannot turn the switch back below 0
2	mjames	46	void EncodeDial(int i) {
		47	if (i < MAX_DIALS && i >= 0) {
		48	int sw_index = i << 1;
		49	// dial 0 uses switches 0 and 1
		50	// dial 1 uses switches 2 and 3
		51	int current = sw_newstate[sw_index] \| (sw_newstate[sw_index + 1] << 1);
		52	switch (dial_last[i]) {
		53	case PH_00:
		54	if (current == PH_10)
		55	dial_pos[i]++;
4	mjames	56	if (current == PH_01 && dial_pos[i]>0)
2	mjames	57	dial_pos[i]--;
		58	break;
		59	case PH_10:
		60	if (current == PH_11)
		61	dial_pos[i]++;
4	mjames	62	if (current == PH_00 && dial_pos[i]>0)
2	mjames	63	dial_pos[i]--;
		64	break;
		65	case PH_11:
		66	if (current == PH_01)
		67	dial_pos[i]++;
4	mjames	68	if (current == PH_10 && dial_pos[i]>0)
2	mjames	69	dial_pos[i]--;
		70	break;
		71	case PH_01:
		72	if (current == PH_00)
		73	dial_pos[i]++;
4	mjames	74	if (current == PH_11 && dial_pos[i]>0)
2	mjames	75	dial_pos[i]--;
		76	break;
		77	default:
		78	break;
		79	}
		80	dial_last[i] = current;
		81	}
		82
		83	}
		84
		85	// this is the interrupt handler , dealling with the switches
		86	void HandleSwitches(void)
		87	{
		88
		89	int i;
		90
		91	for (i = 0; i < MAX_SWITCHES; i++)
		92	{
		93
		94	int sw = HAL_GPIO_ReadPin(sw_arr[i].GPIO, sw_arr[i].Pin) == GPIO_PIN_RESET;
		95
		96	// bouncing, reset counter
4	mjames	97	if (sw == sw_newstate[i])
2	mjames	98	{
		99	sw_count[i] = 0;
		100	}
		101	else
		102	{
		103	// count up to debounce time
		104	if (sw_count[i] < DEBOUNCE_TIME)
		105	{
		106	sw_count[i]++;
		107
		108	if (sw_count[i] == DEBOUNCE_TIME)
		109	{
		110	sw_newstate[i] = sw;
		111	}
		112	}
		113	}
		114	}
		115	// we now have debounced switch states in sw_newstate . So we can go ahead and feed some of the
		116
		117	EncodeDial(0);
		118	EncodeDial(1);
		119
		120	}
		121
		122	void zero_dial(int dial) {
		123	if(dial>=0 && dial < MAX_DIALS)
		124	dial_pos[dial]= 0;
		125	}
		126

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(root)/trunk/Src/switches.c – Rev 4