altos/driver: Improve quadrature debouncing for mechanical encoders

Track state of encoder better and only bump values when the full
motion is detected (all four states).

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/drivers/ao_quadrature.c b/src/drivers/ao_quadrature.c
index 98bd7c083f7eaaec4f0bdcb33f5025e0c7f0bd61..59e845181ceea6f5f43f0fe1c854f185e2806076 100644 (file)
--- a/src/drivers/ao_quadrature.c
+++ b/src/drivers/ao_quadrature.c
@@ -23,6 +23,10 @@
 #include <ao_event.h>
 
 __xdata int32_t ao_quadrature_count[AO_QUADRATURE_COUNT];
+#ifndef AO_QUADRATURE_SINGLE_CODE
+static int8_t ao_quadrature_step[AO_QUADRATURE_COUNT];
+#endif
+
 static uint8_t  ao_quadrature_state[AO_QUADRATURE_COUNT];
 
 struct ao_debounce {
@@ -40,7 +44,7 @@ static struct ao_debounce ao_debounce_state[AO_QUADRATURE_COUNT][2];
 #define isr(q)  ao_quadrature_isr_ ## q
 
 #ifndef AO_QUADRATURE_DEBOUNCE
-#define AO_QUADRATURE_DEBOUNCE 30
+#error must define AO_QUADRATURE_DEBOUNCE
 #endif
 
 static uint8_t
@@ -75,8 +79,21 @@ ao_quadrature_read(struct stm_gpio *gpio, uint8_t pin_a, uint8_t pin_b, struct a
 #define _ao_quadrature_get(q)  ao_quadrature_read(port(q), bita(q), bitb(q), ao_debounce_state[q])
 
 static void
-_ao_quadrature_queue(uint8_t q, int8_t step)
+_ao_quadrature_step(uint8_t q, int8_t step)
 {
+#ifndef AO_QUADRATURE_SINGLE_CODE
+       ao_quadrature_step[q] += step;
+       if (ao_quadrature_state[q] != 0)
+               return;
+       if (ao_quadrature_step[q] >= 4) {
+               ao_quadrature_step[q] = 0;
+               step = 1;
+       } else if (ao_quadrature_step[q] <= -4) {
+               ao_quadrature_step[q] = 0;
+               step = -1;
+       } else
+               return;
+#endif
        ao_quadrature_count[q] += step;
 #if AO_EVENT
        ao_event_put_isr(AO_EVENT_QUADRATURE, q, step);
@@ -84,39 +101,28 @@ _ao_quadrature_queue(uint8_t q, int8_t step)
        ao_wakeup(&ao_quadrature_count[q]);
 }
 
-#if AO_QUADRATURE_SINGLE_CODE
-struct ao_quadrature_step {
-       uint8_t inc;
-       uint8_t dec;
+static const struct {
+       uint8_t prev, next;
+} ao_quadrature_steps[4] = {
+       [0] { .prev = 2, .next = 1 },
+       [1] { .prev = 0, .next = 3 },
+       [3] { .prev = 1, .next = 2 },
+       [2] { .prev = 3, .next = 0 },
 };
 
-static struct ao_quadrature_step ao_quadrature_steps[4] = {
-       [0] = { .inc = 1, .dec = 2 },
-       [1] = { .inc = 3, .dec = 0 },
-       [3] = { .inc = 2, .dec = 1 },
-       [2] = { .inc = 0, .dec = 3 },
-};
-#endif
-
 static void
 _ao_quadrature_set(uint8_t q, uint8_t new) {
-       uint8_t old = ao_quadrature_state[q];
+       uint8_t old;
 
-#ifdef AO_QUADRATURE_SINGLE_CODE
-       if (new == ao_quadrature_steps[old].inc) {
-               _ao_quadrature_queue(q, 1);
-       } else if (new == ao_quadrature_steps[old].dec) {
-               _ao_quadrature_queue(q, -1);
-       }
-#else
-       if (old != new && new == 0) {
-               if (old == 2)
-                       _ao_quadrature_queue(q, 1);
-               else if (old == 1)
-                       _ao_quadrature_queue(q, -1);
-       }
-#endif
+       ao_arch_block_interrupts();
+       old = ao_quadrature_state[q];
        ao_quadrature_state[q] = new;
+       ao_arch_release_interrupts();
+
+       if (new == ao_quadrature_steps[old].next)
+               _ao_quadrature_step(q, 1);
+       else if (new == ao_quadrature_steps[old].prev)
+               _ao_quadrature_step(q, -1);
 }
 
 static void
@@ -151,21 +157,32 @@ ao_quadrature_test(void)
        uint8_t q;
        int32_t c;
        uint8_t s;
+#ifndef AO_QUADRATURE_SINGLE_CODE
+       int8_t t = 0;
+#endif
 
        ao_cmd_decimal();
        q = ao_cmd_lex_i;
-       if (q >= AO_QUADRATURE_COUNT) {
+       if (q >= AO_QUADRATURE_COUNT)
                ao_cmd_status = ao_cmd_syntax_error;
+       if (ao_cmd_status != ao_cmd_success)
                return;
-       }
 
        c = -10000;
        s = 0;
        while (ao_quadrature_count[q] != 10) {
                if (ao_quadrature_count[q] != c ||
-                   ao_quadrature_state[q] != s) {
+#ifndef AO_QUADRATURE_SINGLE_CODE
+                   ao_quadrature_step[q] != t ||
+#endif
+                   ao_quadrature_state[q] != s)
+               {
                        c = ao_quadrature_count[q];
                        s = ao_quadrature_state[q];
+#ifndef AO_QUADRATURE_SINGLE_CODE
+                       t = ao_quadrature_step[q];
+                       printf("step %3d ", t);
+#endif
                        printf ("count %3d state %2x\n", c, s);
                        flush();
                }

diff --git a/src/telelco-v0.2/ao_pins.h b/src/telelco-v0.2/ao_pins.h
index b90fca8b7bcdd4b38cadfeaf18bd3878bc868fee..f0da4fe448a9625d79d37ed54dfbef585630eea3 100644 (file)
--- a/src/telelco-v0.2/ao_pins.h
+++ b/src/telelco-v0.2/ao_pins.h
@@ -253,6 +253,7 @@
 #define AO_QUADRATURE_1_B      0
 
 #define AO_QUADRATURE_BOX      1
+#define AO_QUADRATURE_DEBOUNCE 10
 
 /*
  * Buttons

diff --git a/src/telelco-v0.3/ao_pins.h b/src/telelco-v0.3/ao_pins.h
index 6fd897a0011c821a6d960cdd60f4099d4d10a981..6023739cb182f7d5e38ad5b5e726cb1e967bd5d9 100644 (file)
--- a/src/telelco-v0.3/ao_pins.h
+++ b/src/telelco-v0.3/ao_pins.h
@@ -252,6 +252,7 @@
 #define AO_QUADRATURE_1_B      0
 
 #define AO_QUADRATURE_BOX      1
+#define AO_QUADRATURE_DEBOUNCE 10
 
 /*
  * Buttons