altos/driver: Add support for one-step-per-click quadrature encoder

The mechanical encoders go through all four steps per click while the
optical ones have a single step per click. Support both kinds.

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

diff --git a/src/drivers/ao_quadrature.c b/src/drivers/ao_quadrature.c
index d9cdfe7c154334419679fdef2de7c58ec35caec8..98bd7c083f7eaaec4f0bdcb33f5025e0c7f0bd61 100644 (file)
--- a/src/drivers/ao_quadrature.c
+++ b/src/drivers/ao_quadrature.c
@@ -55,6 +55,7 @@ ao_debounce(uint8_t cur, struct ao_debounce *debounce)
        }
        return debounce->state;
 #else
+       (void) debounce;
        return cur;
 #endif
 }
@@ -83,16 +84,38 @@ _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 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];
 
+#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_quadrature_state[q] = new;
 }