60d62d42dc3bd3e1b9344ab76ed0930afcf88f9b

For underflow detection, instead of using a signed value

Signed-off-by: Michel Pollet <buserror@gmail.com>

diff --git a/examples/board_reprap/src/stepper.c b/examples/board_reprap/src/stepper.c
index 23f6e7d5a849bdde0bfd5d4c6ee6e6695abb4889..81acda644873f2f06d94d355de5688c72b694f94 100644 (file)
--- a/examples/board_reprap/src/stepper.c
+++ b/examples/board_reprap/src/stepper.c
@@ -79,9 +79,7 @@ stepper_step_hook(
                return;
        if (value)
                return;
-       p->position += p->dir ? 1 : -1;
-       if (p->position < 0)
-               p->position = 0;
+       p->position += !p->dir && p->position == 0 ? 0 : p->dir ? 1 : -1;
        if (p->endstop && p->position < p->endstop)
                p->position = p->endstop;
        if (p->max_position > 0 && p->position > p->max_position)

diff --git a/examples/board_reprap/src/stepper.h b/examples/board_reprap/src/stepper.h
index 14b0df183d8eca27caac9eec9b3429666be441fb..9f450ac8a1547042091ba1d7459ef216032a94ef 100644 (file)
--- a/examples/board_reprap/src/stepper.h
+++ b/examples/board_reprap/src/stepper.h
@@ -40,7 +40,7 @@ typedef struct stepper_t {
        char name[32];
        int enable : 1, dir : 1, trace : 1;
        double steps_per_mm;
-       int64_t position;       // in steps
+       uint64_t        position;       // in steps
        uint64_t max_position;
        uint64_t endstop;
        avr_cycle_count_t timer_period;