From 0d9a09a138fd473124b700ada6d9f0f46756db1d Mon Sep 17 00:00:00 2001
From: Pascal Pieper <accounts@pascalpieper.de>
Date: Sat, 15 Jan 2022 22:49:00 +0100
Subject: [PATCH] [Doc] Include safety output pin

Signed-off-by: Pascal Pieper <accounts@pascalpieper.de>
---
 config/sample-pwm-tool.cfg | 13 ++++++++++---
 docs/Using_PWM_Tools.md    |  2 ++
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/config/sample-pwm-tool.cfg b/config/sample-pwm-tool.cfg
index 38d640de5491..f0990993e3c0 100644
--- a/config/sample-pwm-tool.cfg
+++ b/config/sample-pwm-tool.cfg
@@ -3,7 +3,7 @@
 # See docs/Using_PWM_Tools.md for a more detailed description.
 
 [output_pin TOOL]
-pin: !ar9       # use your fan's pin number
+pin: !PIN       # use your fan's pin number
 pwm: True
 #hardware_pwm: True
 # Using hardware PWM is optional.
@@ -27,19 +27,26 @@ high_throughput: True
 # needs to be in default speed (off), or else the MCU will
 # do a safety-shutdown.
 
+[output_pin TOOL_ENABLE]
+pin: !OTHER_PIN
+shutdown_value: 0
+
 [gcode_macro M3]
 gcode:
+    SET_PIN PIN=TOOL_ENABLE VALUE=1
     {% set S = params.S|default(0.0)|float %}
     SET_PIN PIN=TOOL VALUE={S / 255.0}
 
 [gcode_macro M4]
 gcode:
+    SET_PIN PIN=TOOL_ENABLE VALUE=1
     {% set S = params.S|default(0.0)|float %}
     SET_PIN PIN=TOOL VALUE={S / 255.0}
 
 [gcode_macro M5]
 gcode:
     SET_PIN PIN=TOOL VALUE=0
+    SET_PIN PIN=TOOL_ENABLE VALUE=0
 
 
 # Optional: LCD Menu Control
@@ -47,13 +54,13 @@ gcode:
 [menu __main __control __toolonoff]
 type: input
 enable: {'output_pin TOOL' in printer}
-name: Fan: {'ON ' if menu.input else 'OFF'}
+name: Tool: {'ON ' if menu.input else 'OFF'}
 input: {printer['output_pin TOOL'].value}
 input_min: 0
 input_max: 1
 input_step: 1
 gcode:
-    M3 S{255 if menu.input else 0}
+    SET_PIN PIN=TOOL_ENABLE VALUE={1 if menu.input else 0}
 
 [menu __main __control __toolspeed]
 type: input
diff --git a/docs/Using_PWM_Tools.md b/docs/Using_PWM_Tools.md
index 79a62a290e9f..03fba05990b1 100644
--- a/docs/Using_PWM_Tools.md
+++ b/docs/Using_PWM_Tools.md
@@ -23,6 +23,8 @@ laser-goggles of the right wavelength if the laser is powered;
 and to disconnect the laser when it is not needed.
 Also, you should consider using a safety timeout,
 so that when your host dies unexpectedly, the tool will stop.
+An additional safety layer would be powering your tool through the hotend-heater pin.
+In the configuration, the additional `[output_pin]` would be activated by `M3/M4` and disabled by `M5`.
 
 For an example configuration, see [config/sample-pwm-tool.cfg](/config/sample-pwm-tool.cfg).