bricks/ev3/modules: Split off DC motor control.

We'll also be using this for the IR Control app.

Author: laurensvalk

bricks/_common/micropython.c

@@ -306,7 +306,7 @@ pbio_error_t pbsys_main_program_validate(pbsys_main_program_t *program) {
                 return PBIO_SUCCESS;
             #endif
             #if PBSYS_CONFIG_FEATURE_BUILTIN_USER_PROGRAM_EV3_APPS
-            case PBIO_PYBRICKS_USER_PROGRAM_ID_EV3_MOTOR_CONTROL:
+            case PBIO_PYBRICKS_USER_PROGRAM_ID_EV3_MOTOR_BUTTON_CONTROL:
                 return PBIO_SUCCESS;
             #endif
             default:
@@ -400,9 +400,9 @@ void pbsys_main_run_program(pbsys_main_program_t *program) {
         #endif
 
         #if PBSYS_CONFIG_FEATURE_BUILTIN_USER_PROGRAM_EV3_APPS
-        case PBIO_PYBRICKS_USER_PROGRAM_ID_EV3_MOTOR_CONTROL:
+        case PBIO_PYBRICKS_USER_PROGRAM_ID_EV3_MOTOR_BUTTON_CONTROL:
             pb_package_pybricks_init(false);
-            pyexec_frozen_module("_ev3_motor_control.py", false);
+            pyexec_frozen_module("_ev3_motor_button_control.py", false);
             break;
         #endif
 

bricks/ev3/manifest.py

@@ -1,2 +1,3 @@
 include("../_common/manifest.py")
-freeze_as_mpy("../ev3/modules", "_ev3_motor_control.py")
+freeze_as_mpy("../ev3/modules", "_ev3_motor_button_control.py")
+freeze_as_mpy("../ev3/modules", "_ev3_motor_dc.py")

bricks/ev3/modules/_ev3_motor_button_control.py

@@ -0,0 +1,86 @@
+from pybricks.tools import wait
+from pybricks.parameters import ImageFile, Button, Port, Color
+from pybricks.hubs import EV3Brick
+from pybricks.ev3devices import Motor
+
+from _ev3_motor_dc import motor_set_dc
+
+
+# True means A&D pair is active. False means B&C pair is active.
+pair_ad_active = False
+
+# Power used for all motors if active.
+POWER = 100
+
+# Preload to avoid repeated allocation.
+IMG_POS = ImageFile._ROTATE_CW18
+IMG_NEG = ImageFile._ROTATE_CCW18
+IMG_AD = ImageFile._APP_MOTOR_CONTROL_AD
+IMG_BC = ImageFile._APP_MOTOR_CONTROL_BC
+
+# UI is one of two prebuilt images from lms2012.
+ev3 = EV3Brick()
+
+
+def draw_ui():
+    file = IMG_AD if pair_ad_active else IMG_BC
+    ev3.screen.draw_image(0, 20, file)
+    ev3.screen.draw_box(0, 0, 177, 16, fill=True, color=Color.WHITE)
+
+
+draw_ui()
+
+while True:
+    # Start with light on and motors off.
+    draw_ui()
+    ev3.light.on(Color.GREEN)
+    for m in range(4):
+        motor_set_dc(m, 0)
+
+    # Wait for anything to happen.
+    while not (pressed := ev3.buttons.pressed()):
+        wait(10)
+
+    # Center button toggles motor pair
+    if Button.CENTER in pressed:
+        pair_ad_active = not pair_ad_active
+        draw_ui()
+        while any(ev3.buttons.pressed()):
+            wait(10)
+        continue
+
+    # Determine motor power for horizontal buttons.
+    dc_x = 0
+    if Button.RIGHT in pressed:
+        dc_x += POWER
+    if Button.LEFT in pressed:
+        dc_x -= POWER
+
+    # Determine motor power for vertical buttons.
+    dc_y = 0
+    if Button.UP in pressed:
+        dc_y += POWER
+    if Button.DOWN in pressed:
+        dc_y -= POWER
+
+    # Activity heartbeat.
+    if dc_x or dc_y:
+        ev3.light.blink(Color.GREEN, [100, 100, 800, 100])
+    else:
+        ev3.light.on(Color.GREEN)
+
+    # Drive one or two motors.
+    output = [0, 0, 0, 0]
+    index_x = 3 if pair_ad_active else 2
+    index_y = 0 if pair_ad_active else 1
+    output[index_x] = motor_set_dc(index_x, dc_x)
+    output[index_y] = motor_set_dc(index_y, dc_y)
+
+    # Draw output indicators if active.
+    for m in range(len(output)):
+        if output[m]:
+            ev3.screen.draw_image(20 + m * 40, 2, IMG_POS if output[m] > 0 else IMG_NEG)
+
+    # Keep going until button state changes.
+    while ev3.buttons.pressed() == pressed:
+        wait(10)

bricks/ev3/modules/_ev3_motor_control.py

@@ -0,0 +1,43 @@
+from pybricks.ev3devices import Motor
+from pybricks.parameters import Port
+
+
+motors = [None, None, None, None]
+ports = [Port.A, Port.B, Port.C, Port.D]
+
+
+def motor_set_dc(index: int, dc: int):
+    """Sets the DC value of a motor if it is plugged in.
+
+    Returns the given DC value if a nonzero value was set, else 0.
+    """
+
+    # If there was a motor, close if it got unplugged.
+    if motors[index] is not None:
+        try:
+            motors[index].angle()
+        except OSError:
+            motors[index].close()
+            motors[index] = None
+            pass
+
+    # If there isn't a motor, try to initialize it now.
+    if motors[index] is None:
+        try:
+            motors[index] = Motor(ports[index])
+        except OSError:
+            pass
+
+    # Drive the motor if there is one.
+    if motors[index]:
+        try:
+            if dc:
+                motors[index].dc(dc)
+                return dc
+            else:
+                motors[index].stop()
+        except OSError:
+            motors[index].close()
+            motors[index] = None
+
+    return 0

bricks/ev3/modules/_ev3_motor_dc.py

@@ -1,2 +1,3 @@
 include("../_common/manifest.py")
-freeze_as_mpy("../ev3/modules", "_ev3_motor_control.py")
+freeze_as_mpy("../ev3/modules", "_ev3_motor_button_control.py")
+freeze_as_mpy("../ev3/modules", "_ev3_motor_dc.py")

bricks/virtualhub/manifest.py

@@ -72,7 +72,7 @@ typedef enum {
     /**
      * Program to control EV3 motors with the buttons.
      */
-    PBIO_PYBRICKS_USER_PROGRAM_ID_EV3_MOTOR_CONTROL = 133,
+    PBIO_PYBRICKS_USER_PROGRAM_ID_EV3_MOTOR_BUTTON_CONTROL = 133,
 } pbio_pybricks_user_program_id_t;
 
 /**

lib/pbio/include/pbio/protocol.h

@@ -84,7 +84,7 @@ static pbsys_hmi_ev3_ui_t state;
  * Available apps on app tab.
  */
 static const char *apps[] = {
-    " Motor Control",
+    " Motor Button Control",
 };
 
 /**
@@ -279,13 +279,15 @@ pbsys_hmi_ev3_ui_action_t pbsys_hmi_ev3_ui_handle_button(pbio_button_flags_t but
             *payload = state.selection[PBSYS_HMI_EV3_UI_TAB_PROGRAMS];
             return PBSYS_HMI_EV3_UI_ACTION_RUN_PROGRAM;
         } else if (state.tab == PBSYS_HMI_EV3_UI_TAB_APPS) {
-            if (state.selection[PBSYS_HMI_EV3_UI_TAB_APPS] == 0) {
-                *payload = PBIO_PYBRICKS_USER_PROGRAM_ID_EV3_MOTOR_CONTROL;
-                return PBSYS_HMI_EV3_UI_ACTION_RUN_PROGRAM;
+            switch (state.selection[PBSYS_HMI_EV3_UI_TAB_APPS]) {
+                case 0:
+                    *payload = PBIO_PYBRICKS_USER_PROGRAM_ID_EV3_MOTOR_BUTTON_CONTROL;
+                    return PBSYS_HMI_EV3_UI_ACTION_RUN_PROGRAM;
+                default:
+                    // Other apps not yet implemented.
+                    state.overlay = PBSYS_HMI_EV3_UI_OVERLAY_COMING_SOON;
+                    return PBSYS_HMI_EV3_UI_ACTION_NONE;
             }
-            // Other apps not yet implemented.
-            state.overlay = PBSYS_HMI_EV3_UI_OVERLAY_COMING_SOON;
-            return PBSYS_HMI_EV3_UI_ACTION_NONE;
         } else {
             // Settings don't currently do anything, just displays info.
             return PBSYS_HMI_EV3_UI_ACTION_NONE;