delta: Initial support for linear delta kinematics

This adds support for delta based robots.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

config/example-delta.cfg

@@ -0,0 +1,94 @@
+# This file serves as documentation for config parameters of delta
+# style printers. One may copy and edit this file to configure a new
+# delta printer. Only parameters unique to delta printers are
+# described here - see the "example.cfg" file for description of
+# common config parameters.
+
+# DO NOT COPY THIS FILE WITHOUT CAREFULLY READING AND UPDATING IT
+# FIRST. Incorrectly configured parameters may cause damage.
+
+# The stepper_a section describes the stepper controlling the front
+# left tower (at 210 degrees). This section also controls the homing
+# parameters (homing_speed, homing_retract_dist) and maximum tower
+# length (position_max) for all towers.
+[stepper_a]
+step_pin: ar54
+dir_pin: ar55
+enable_pin: !ar38
+step_distance: .01
+max_velocity: 200
+max_accel: 3000
+endstop_pin: ^ar2
+homing_speed: 50.0
+position_endstop: 297.05
+position_max: 297.55
+
+# The stepper_b section describes the stepper controlling the front
+# right tower (at 330 degrees)
+[stepper_b]
+step_pin: ar60
+dir_pin: ar61
+enable_pin: !ar56
+step_distance: .01
+max_velocity: 200
+max_accel: 3000
+endstop_pin: ^ar15
+position_endstop: 297.05
+
+# The stepper_c section describes the stepper controlling the rear
+# tower (at 90 degrees)
+[stepper_c]
+step_pin: ar46
+dir_pin: ar48
+enable_pin: !ar62
+step_distance: .01
+max_velocity: 200
+max_accel: 3000
+endstop_pin: ^ar19
+position_endstop: 297.05
+
+[extruder]
+step_pin: ar26
+dir_pin: ar28
+enable_pin: !ar24
+step_distance: .0022
+max_velocity: 200
+max_accel: 3000
+heater_pin: ar10
+thermistor_pin: analog13
+thermistor_type: ATC Semitec 104GT-2
+control: pid
+pid_Kp: 22.2
+pid_Ki: 1.08
+pid_Kd: 114
+min_temp: 0
+max_temp: 250
+
+[heater_bed]
+heater_pin: ar8
+thermistor_pin: analog14
+thermistor_type: EPCOS 100K B57560G104F
+control: watermark
+min_temp: 0
+max_temp: 130
+
+# Extruder print fan (omit section if fan not present)
+#[fan]
+#pin: ar9
+#hard_pwm: 1
+
+[mcu]
+serial: /dev/ttyACM0
+baud: 250000
+pin_map: arduino
+
+[printer]
+kinematics: delta
+#   This option must be "delta" for linear delta printers
+delta_arm_length: 333.0
+#   Length (in mm) of the diagonal rods that connect the linear axes
+#   to the print head
+delta_radius: 174.75
+#   Radius (in mm) of the horizontal circle formed by the three linear
+#   axis towers. This parameter may also be calculated as:
+#    delta_radius = smooth_rod_offset - effector_offset - carriage_offset

config/example.cfg

@@ -1,5 +1,6 @@
 # This file serves as documentation for config parameters. One may
-# copy and edit this file to configure a new printer.
+# copy and edit this file to configure a new cartesian style
+# printer. For delta style printers, see the "example-delta.cfg" file.
 
 # DO NOT COPY THIS FILE WITHOUT CAREFULLY READING AND UPDATING IT
 # FIRST. Incorrectly configured parameters may cause damage.
@@ -189,7 +190,7 @@ custom:
 # The printer section controls high level printer settings
 [printer]
 kinematics: cartesian
-#   This option must currently always be "cartesian"
+#   This option must be "cartesian" for cartesian printers
 motor_off_time: 60
 #   Time (in seconds) of idle time before the printer will try to
 #   disable active motors.