mcp4018: Add SET_DIGIPOT command to mcp4018 implementation (#5737)

Added a SET_DIGIPOT command to the mcp4018 implementation.
Previously the mcp4018 was read only, and set at the time of
configuration.  This allows you to change the value during a
print, which is needed for some older printers that need to
lower the stepper current during preheating.

Signed-off-by: Jake Bordens <jake@allaboutjake.com>

1 files changed, 47 insertions, 0 deletions

diff --git a/config/sample-macros.cfg b/config/sample-macros.cfg
index 3590268c..7b68f5d0 100644
--- a/config/sample-macros.cfg
+++ b/config/sample-macros.cfg
@@ -261,3 +261,50 @@ gcode:
   {% if 'U' in params %}
     EXCLUDE_OBJECT RESET=1 NAME={params.U}
   {% endif %}
+
+######################################################################
+# G130: Set digital potentiometer value
+######################################################################
+
+# The macro below uses the MCP4018 SET_DIGIPOT command to implement
+# a `G130` as used on classic Mightyboard-based printers such as
+# The Makerbot Replicator 2/2X.
+#
+# The `G130` command can be used to lower the stepper current
+# during preheating and raise the current again prior to starting
+# the print.  This is necessary for printers with smaller power
+# supplies that needed all the power to heat the bed.
+#
+# This macro requires one or more [mcp4018] configuration sections:
+# (x_axis_pot, y_axis_pot, z_axis_pot, a_axis_pot, b_axis_pot)
+#
+# Example: G130 X20 Y20 Z20 A20 B20 ; Lower stepper Vrefs while heating
+
+[gcode_macro G130]
+gcode:
+  M400
+  {% if ('X' in params) and ('mcp4018 x_axis_pot' in printer.configfile.config) %}
+    {% set x_value = params['X']|float %}
+    {% set x_axis_pot_scale = printer.configfile.config["mcp4018 x_axis_pot"].scale|float %}
+    SET_DIGIPOT DIGIPOT=x_axis_pot WIPER={ x_axis_pot_scale * (x_value / 127.0)}
+  {% endif %}
+  {% if ('Y' in params) and ('mcp4018 y_axis_pot' in printer.configfile.config) %}
+    {% set y_value = params['Y']|float %}
+    {% set y_axis_pot_scale = printer.configfile.config["mcp4018 y_axis_pot"].scale|float %}
+    SET_DIGIPOT DIGIPOT=y_axis_pot WIPER={ y_axis_pot_scale * (y_value / 127.0)}
+  {% endif %}
+  {% if ('Z' in params) and ('mcp4018 z_axis_pot' in printer.configfile.config) %}
+    {% set z_value = params['Z']|float %}
+    {% set z_axis_pot_scale = printer.configfile.config["mcp4018 z_axis_pot"].scale|float %}
+    SET_DIGIPOT DIGIPOT=z_axis_pot WIPER={ z_axis_pot_scale * (z_value / 127.0)}
+  {% endif %}
+  {% if ('A' in params) and ('mcp4018 a_axis_pot' in printer.configfile.config) %}
+    {% set a_value = params['A']|float %}
+    {% set a_axis_pot_scale = printer.configfile.config["mcp4018 a_axis_pot"].scale|float %}
+    SET_DIGIPOT DIGIPOT=a_axis_pot WIPER={ a_axis_pot_scale * (a_value / 127.0)}
+  {% endif %}
+  {% if ('B' in params) and ('mcp4018 b_axis_pot' in printer.configfile.config) %}
+    {% set b_value = params['B']|float %}
+    {% set b_axis_pot_scale = printer.configfile.config["mcp4018 b_axis_pot"].scale|float %}
+    SET_DIGIPOT DIGIPOT=b_axis_pot WIPER={ b_axis_pot_scale * (b_value / 127.0)}
+  {% endif %}