- Split Plotter into common and hardware-specific.

- Implemented PCA9685 mode

Author: zuccon

.gitignore

@@ -18,6 +18,7 @@ var/
 *.egg-info/
 .installed.cfg
 *.egg
+.._.DS_Store
 .DS_Store
 .ipynb_checkpoints
 

README.rst

@@ -20,3 +20,37 @@ Documentation
 -------------
 
 `Complete documentation for the project, with detailed instructions on how to build and use it <https://www.brachiograph.art/>`_
+
+Adafruit PCA9685
+----------------
+
+Support for `Adafruit PCA9685 servo controller <https://learn.adafruit.com/16-channel-pwm-servo-driver?view=all>`_ has been implemented.
+
+A PCA9685 based Brachiograph can be instantiated this way::
+
+  from brachiograph import BrachioGraph
+  bg = BrachioGraph(mode="PCA9685")
+
+Github: https://github.com/adafruit/Adafruit_CircuitPython_PCA9685
+
+Servos
+------
+
+The Adafruit PCA9685 mod has been done primarily as an attempt to fix jitter in what apparently are 'bad' servos.
+After adapting the code it turned out that such servos would jitter using the PCA9685 controller anyways.
+Specifically, the issue was that each movement of an arm servo would cause the arm to shake uncontrollably, until stopped by hand.
+
+Using 'good' servos worked, however they haven't been tested without the controller.
+
+**Bad servos**
+
+- 9g Microservo SG90:
+
+  - Robbe RoVoR S0009 Micro-Servo
+  - Velleman Servo VMA600
+
+**Good servos**
+
+- 12g ES08MA:
+
+  - ZHITING

brachiograph.py

@@ -1,224 +1,62 @@
 # coding=utf-8
-
-from time import sleep
-import readchar
-import math
-import numpy
-from turtle_plotter import BrachioGraphTurtle
-from plotter import Plotter
-
-
-class BrachioGraph(Plotter):
+class BrachioGraph():
     """A shoulder-and-elbow drawing robot class."""
 
     def __init__(
         self,
-        virtual: bool = False,  # a virtual plotter runs in software only
-        turtle: bool = False,  # create a turtle graphics plotter
-        turtle_coarseness=None,  # a factor in degrees representing servo resolution
-        #  ----------------- geometry of the plotter -----------------
-        bounds: tuple = [-8, 4, 6, 13],  # the maximum rectangular drawing area
-        inner_arm: float = 8,  # the lengths of the arms
+        mode = "pigpio",           # machine mode: [pigpio|PCA9685|virtual]
+        turtle:  bool = False,     # create a turtle graphics plotter
+        turtle_coarseness = None,  # a factor in degrees representing servo resolution
+
+        resolution: float = 1,     # default resolution of the plotter in cm
+        #  ----------------- geometry of the plotter
+        bounds:    tuple = [-8, 4, 6, 13],  # the maximum rectangular drawing area
+        inner_arm: float = 8,               # the lengths of the arms
         outer_arm: float = 8,
-        #  ----------------- naive calculation values -----------------
-        servo_1_parked_pw: int = 1500,  # pulse-widths when parked
-        servo_2_parked_pw: int = 1500,
-        servo_1_degree_ms: int = -10,  # milliseconds pulse-width per degree
-        servo_2_degree_ms: int = 10,  # reversed for the mounting of the shoulder servo
-        servo_1_parked_angle: int = -90,  # the arm angle in the parked position
-        servo_2_parked_angle: int = 90,
-        #  ----------------- hysteresis -----------------
+
+        #  ----------------- servo calibration
+        angle_offset_servo_shoulder: float = 30,   # offset (in BG's reference model)
+                                                   # for the servo's zero degrees.
+        angle_parked_servo_shoulder: float = -90,  # the arm angle in the parked position
+        angle_parked_servo_elbow:    float = 90,
+        angle_pen_up:                float = 0,
+        angle_pen_down:              float = 30,
+
+        #  ----------------- hysteresis # TODO: implement for PCA9685
         hysteresis_correction_1: int = 0,  # hardware error compensation
         hysteresis_correction_2: int = 0,
-        #  ----------------- servo angles and pulse-widths in lists -----------------
-        servo_1_angle_pws: tuple = [],  # pulse-widths for various angles
-        servo_2_angle_pws: tuple = [],
-        #  ----------------- servo angles and pulse-widths in lists (bi-directional) ------
-        servo_1_angle_pws_bidi: tuple = [],  # bi-directional pulse-widths for various angles
-        servo_2_angle_pws_bidi: tuple = [],
-        #  ----------------- the pen -----------------
-        pw_up: int = 1500,  # pulse-widths for pen up/down
-        pw_down: int = 1100,
-        #  ----------------- physical control -----------------
-        wait: float = None,  # default wait time between operations
-        resolution: float = None,  # default resolution of the plotter in cm
-    ):
 
-        # set the geometry
-        self.inner_arm = inner_arm
-        self.outer_arm = outer_arm
-
-        # Set the x and y position state, so it knows its current x/y position.
-        self.x = -self.inner_arm
-        self.y = self.outer_arm
+        #  ----------------- movement speed
+        wait:       float = 0.05,  # default wait time between operations
+        **kwargs
+    ):
+        if   mode == "PCA9685":
+            from plotter_pca9685 import Plotter
+        elif mode == "pigpio":
+            from plotter_pigpio  import Plotter
+        elif mode == "virtual":
+            from plotter_virtual import Plotter
+        else:
+            print("FATAL: mode {mode} not recognized.")
+            exit(1)
 
-        super().__init__(
+        self.plotter = Plotter(
             bounds=bounds,
-            servo_1_parked_pw=servo_1_parked_pw,
-            servo_2_parked_pw=servo_1_parked_pw,
-            servo_1_degree_ms=servo_1_degree_ms,
-            servo_2_degree_ms=servo_2_degree_ms,
-            servo_1_parked_angle=servo_1_parked_angle,
-            servo_2_parked_angle=servo_2_parked_angle,
+            angle_parked_servo_shoulder=angle_parked_servo_shoulder,
+            angle_parked_servo_elbow=angle_parked_servo_elbow,
+            angle_offset_servo_shoulder=angle_offset_servo_shoulder,
             hysteresis_correction_1=hysteresis_correction_1,
             hysteresis_correction_2=hysteresis_correction_2,
-            servo_1_angle_pws=servo_1_angle_pws,
-            servo_2_angle_pws=servo_2_angle_pws,
-            servo_1_angle_pws_bidi=servo_1_angle_pws_bidi,
-            servo_2_angle_pws_bidi=servo_2_angle_pws_bidi,
-            pw_up=pw_up,
-            pw_down=pw_down,
+            angle_pen_up=angle_pen_up,
+            angle_pen_down=angle_pen_down,
             wait=wait,
             resolution=resolution,
-            virtual=virtual,
             turtle=turtle,
             turtle_coarseness=turtle_coarseness,
+            inner_arm=inner_arm,
+            outer_arm=outer_arm,
+            **kwargs
         )
 
-    def setup_turtle(self, coarseness):
-        self.turtle = BrachioGraphTurtle(
-            inner_arm=self.inner_arm,  # the length of the inner arm (blue)
-            outer_arm=self.outer_arm,  # the length of the outer arm (red)
-            shoulder_centre_angle=-90,  # the starting angle of the inner arm, relative to straight ahead
-            shoulder_sweep=180,  # the arc covered by the shoulder motor
-            elbow_centre_angle=90,  # the centre of the outer arm relative to the inner arm
-            elbow_sweep=180,  # the arc covered by the elbow motor
-            window_size=850,  # width and height of the turtle canvas
-            speed=10,  # how fast to draw
-            machine=self,
-            coarseness=coarseness,
-        )
-
-        self.turtle.draw_grid()
-        self.t = self.turtle
-
-    def test_arcs(self):
-        self.park()
-        elbow_angle = 120
-        self.move_angles(angle_2=elbow_angle)
-
-        for angle_1 in range(-135, 15, 15):
-            self.move_angles(angle_1=angle_1, draw=True)
-
-            for angle_2 in range(elbow_angle, elbow_angle + 16):
-                self.move_angles(angle_2=angle_2, draw=True)
-            for angle_2 in range(elbow_angle + 16, elbow_angle - 16, -1):
-                self.move_angles(angle_2=angle_2, draw=True)
-            for angle_2 in range(elbow_angle - 16, elbow_angle + 1):
-                self.move_angles(angle_2=angle_2, draw=True)
-
-    # ----------------- trigonometric methods -----------------
-
-    def xy_to_angles(self, x=0, y=0):
-        """Return the servo angles required to reach any x/y position."""
-
-        hypotenuse = math.sqrt(x**2 + y**2)
-
-        if hypotenuse > self.inner_arm + self.outer_arm:
-            raise Exception(
-                f"Cannot reach {hypotenuse}; total arm length is {self.inner_arm + self.outer_arm}"
-            )
-
-        hypotenuse_angle = math.asin(x / hypotenuse)
-
-        inner_angle = math.acos(
-            (hypotenuse**2 + self.inner_arm**2 - self.outer_arm**2)
-            / (2 * hypotenuse * self.inner_arm)
-        )
-        outer_angle = math.acos(
-            (self.inner_arm**2 + self.outer_arm**2 - hypotenuse**2)
-            / (2 * self.inner_arm * self.outer_arm)
-        )
-
-        shoulder_motor_angle = hypotenuse_angle - inner_angle
-        elbow_motor_angle = math.pi - outer_angle
-
-        return (math.degrees(shoulder_motor_angle), math.degrees(elbow_motor_angle))
-
-    def angles_to_xy(self, shoulder_motor_angle, elbow_motor_angle):
-        """Return the x/y co-ordinates represented by a pair of servo angles."""
-
-        elbow_motor_angle = math.radians(elbow_motor_angle)
-        shoulder_motor_angle = math.radians(shoulder_motor_angle)
-
-        hypotenuse = math.sqrt(
-            (
-                self.inner_arm**2
-                + self.outer_arm**2
-                - 2
-                * self.inner_arm
-                * self.outer_arm
-                * math.cos(math.pi - elbow_motor_angle)
-            )
-        )
-        base_angle = math.acos(
-            (hypotenuse**2 + self.inner_arm**2 - self.outer_arm**2)
-            / (2 * hypotenuse * self.inner_arm)
-        )
-        inner_angle = base_angle + shoulder_motor_angle
-
-        x = math.sin(inner_angle) * hypotenuse
-        y = math.cos(inner_angle) * hypotenuse
-
-        return (x, y)
-
-    # ----------------- reporting methods -----------------
-
-    def report(self):
-
-        print(f"               -----------------|-----------------")
-        print(f"               Servo 1          |  Servo 2        ")
-        print(f"               -----------------|-----------------")
-
-        h1, h2 = self.hysteresis_correction_1, self.hysteresis_correction_2
-        print(f"hysteresis                 {h1:>2.1f}  |              {h2:>2.1f}")
-
-        pw_1, pw_2 = self.get_pulse_widths()
-        print(f"pulse-width               {pw_1:<4.0f}  |             {pw_2:<4.0f}")
-
-        angle_1, angle_2 = self.angle_1, self.angle_2
-
-        if angle_1 and angle_2:
-
-            print(
-                f"      angle               {angle_1:>4.0f}  |             {angle_2:>4.0f}"
-            )
-
-        print(f"               -----------------|-----------------")
-        print(f"               min   max   mid  |  min   max   mid")
-        print(f"               -----------------|-----------------")
-
-        if (
-            self.angles_used_1
-            and self.angles_used_2
-            and self.pulse_widths_used_1
-            and self.pulse_widths_used_2
-        ):
-
-            min1 = min(self.pulse_widths_used_1)
-            max1 = max(self.pulse_widths_used_1)
-            mid1 = (min1 + max1) / 2
-            min2 = min(self.pulse_widths_used_2)
-            max2 = max(self.pulse_widths_used_2)
-            mid2 = (min2 + max2) / 2
-
-            print(
-                f"pulse-widths  {min1:>4.0f}  {max1:>4.0f}  {mid1:>4.0f}  | {min2:>4.0f}  {max2:>4.0f}  {mid2:>4.0f}"
-            )
-
-            min1 = min(self.angles_used_1)
-            max1 = max(self.angles_used_1)
-            mid1 = (min1 + max1) / 2
-            min2 = min(self.angles_used_2)
-            max2 = max(self.angles_used_2)
-            mid2 = (min2 + max2) / 2
-
-            print(
-                f"      angles  {min1:>4.0f}  {max1:>4.0f}  {mid1:>4.0f}  | {min2:>4.0f}  {max2:>4.0f}  {mid2:>4.0f}"
-            )
-
-        else:
-
-            print(
-                "No data recorded yet. Try calling the BrachioGraph.box() method first."
-            )
+if __name__=="__main__":
+    bg = BrachioGraph(mode="virtual",turtle=True)

linedraw.py

@@ -6,6 +6,7 @@
 import argparse
 import json
 import time
+import os
 
 from PIL import Image, ImageDraw, ImageOps
 
@@ -35,6 +36,7 @@ def image_to_json(
     repeat_contours=1,
     draw_hatch=False,
     repeat_hatch=1,
+    output_filename_append=""
 ):
 
     lines = vectorise(
@@ -44,9 +46,10 @@ def image_to_json(
         repeat_contours,
         draw_hatch,
         repeat_hatch,
+        output_filename_append
     )
 
-    filename = json_folder + image_filename + ".json"
+    filename = json_folder + os.path.basename(image_filename) + output_filename_append + ".json"
     lines_to_file(lines, filename)
 
 
@@ -110,6 +113,7 @@ def vectorise(
     repeat_contours=1,
     draw_hatch=False,
     repeat_hatch=1,
+    output_filename_append=""
 ):
 
     image = None
@@ -173,7 +177,7 @@ def vectorise(
         segments = segments + len(line) - 1
     print(len(lines), "lines,", segments, "segments.")
 
-    f = open(svg_folder + image_filename + ".svg", "w")
+    f = open(svg_folder + os.path.basename(image_filename) + output_filename_append + ".svg", "w")
     f.write(makesvg(lines))
     f.close()