From 5a6a429bc0c8366512a39b5e87ebad62bd63c740 Mon Sep 17 00:00:00 2001
From: Kevin O'Connor <kevin@koconnor.net>
Date: Mon, 7 Jan 2019 12:05:37 -0500
Subject: [PATCH] bltouch: Take into account clock skew when calculating
command duration
We want the duration of each command to be an exact multiple of
SIGNAL_PERIOD. The durations might not be exact if the bltouch is on
a secondary mcu. Account for this in send_cmd().
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
---
klippy/extras/bltouch.py | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/klippy/extras/bltouch.py b/klippy/extras/bltouch.py
index 93256707f..52f5d42d2 100644
--- a/klippy/extras/bltouch.py
+++ b/klippy/extras/bltouch.py
@@ -83,7 +83,11 @@ class BLTouchEndstopWrapper:
self.next_cmd_time = print_time
def send_cmd(self, cmd, duration=MIN_CMD_TIME):
self.mcu_pwm.set_pwm(self.next_cmd_time, Commands[cmd] / SIGNAL_PERIOD)
- self.next_cmd_time += max(duration, MIN_CMD_TIME)
+ # Translate duration to ticks to avoid any secondary mcu clock skew
+ mcu = self.mcu_pwm.get_mcu()
+ cmd_clock = mcu.print_time_to_clock(self.next_cmd_time)
+ cmd_clock += mcu.seconds_to_clock(max(duration, MIN_CMD_TIME))
+ self.next_cmd_time = mcu.clock_to_print_time(cmd_clock)
return self.next_cmd_time
def verify_state(self, check_start_time, check_end_time, triggered, msg):
# Perform endstop check to verify bltouch reports desired state