pybricks.common.charger: change return value of connected()

CHANGELOG.md

@@ -22,12 +22,17 @@
 - Re-implemented `hub.imu.heading()` to use optionally use the projection of 3D
   orientation to improve performance when the hub is lifted off the ground.
   The 1D-based heading remains the default for now.
+- Change return value of connected() property from bool to int using the value
+  of pbdrv_usb_get_bcd(). This will allow pro users to be able to tell if they
+  have a "nonstandard" charger that could prevent proper
+  charging ([pybricks-micropython#274]).
 
 ### Fixed
 - Fixed `DriveBase.angle()` getting an incorrectly rounded gyro value, which
   could cause `turn(360)` to be off by a degree ([support#1844]).
 - Fixed `hub` silently ignoring non-orthogonal base axis when it should raise.
 
+[pybricks-micropython#274]: https://github.com/pybricks/pybricks-micropython/pull/274
 [support#943]: https://github.com/pybricks/support/issues/943
 [support#1886]: https://github.com/pybricks/support/issues/1886
 [support#1844]: https://github.com/pybricks/support/issues/1844

lib/pbio/include/pbdrv/usb.h

@@ -15,16 +15,18 @@
  * Indicates battery charging capabilites that were detected on a USB port.
  */
 typedef enum {
+    // NOTE: These values are part of the MicroPython API, don't change the numbers.
+
     /** The USB cable is not connected (no VBUS). */
-    PBDRV_USB_BCD_NONE,
+    PBDRV_USB_BCD_NONE = 0,
     /** The USB cable is connected to a non-standard charger or PS/2 port. */
-    PBDRV_USB_BCD_NONSTANDARD,
+    PBDRV_USB_BCD_NONSTANDARD = 1,
     /** The USB cable is connected to standard downstream port. */
-    PBDRV_USB_BCD_STANDARD_DOWNSTREAM,
+    PBDRV_USB_BCD_STANDARD_DOWNSTREAM = 2,
     /** The USB cable is connected to charging downstream port. */
-    PBDRV_USB_BCD_CHARGING_DOWNSTREAM,
+    PBDRV_USB_BCD_CHARGING_DOWNSTREAM = 3,
     /** The USB cable is connected to dedicated charging port. */
-    PBDRV_USB_BCD_DEDICATED_CHARGING,
+    PBDRV_USB_BCD_DEDICATED_CHARGING = 4,
 } pbdrv_usb_bcd_t;
 
 #if PBDRV_CONFIG_USB

pybricks/common/pb_type_charger.c

@@ -32,7 +32,7 @@ static mp_obj_t Charger_status(mp_obj_t self_in) {
 static MP_DEFINE_CONST_FUN_OBJ_1(Charger_status_obj, Charger_status);
 
 static mp_obj_t Charger_connected(mp_obj_t self_in) {
-    return mp_obj_new_bool(pbdrv_usb_get_bcd() != PBDRV_USB_BCD_NONE);
+    return mp_obj_new_int(pbdrv_usb_get_bcd());
 }
 static MP_DEFINE_CONST_FUN_OBJ_1(Charger_connected_obj, Charger_connected);