Merge pull request #4683 from DavePutz/issue_4661

Issue #4661 - Wrap pulsein values when maxlen is exceeded.

Author: tannewt

ports/raspberrypi/common-hal/pulseio/PulseIn.c

@@ -142,8 +142,15 @@ void common_hal_pulseio_pulsein_interrupt() {
             // ignore pulses that are too short
             if (result <= MAX_PULSE && result > MIN_PULSE) {
                 self->buffer[buf_index] = (uint16_t) result;
-                buf_index++;
-                self->len++;
+	        if (self->len < self->maxlen) {
+                   self->len++;
+	        }
+	        if (buf_index < self->maxlen) {
+                   buf_index++;
+                } else {
+                   self->start = 0;
+                   buf_index = 0;
+                }
             }
         }
     }