moved motor_socket to class variable instead of instance variable to …

…fix bugs

Multiple motors on same can bus do not work unless either this is done or better filtering is implemented. Until then, multiple can bus is not supported.

README.md

@@ -19,7 +19,7 @@ Install via:
 
 # Documentation
 
-- Useful videos: 
+- Useful videos:
     - [From T-Motor](https://www.youtube.com/watch?v=hbqQCgebaF8)
     - [From Skyentific](https://www.youtube.com/watch?v=HzY9vzgPZkA)
 - [Motor Datasheets](https://store.cubemars.com/images/file/20220307/1646619452473352.pdf)
@@ -177,6 +177,6 @@ To add a new constants configuration use the `change_motor_constants` function o
 
 # Known Issues
 
-**Issue Fixed**: When having 2 motors on the CAN bus with either PCAN CAN-USB or ESD CAN-USB/2, sometimes the motors experience an initial short *kick/impulse* at when they are enabled again after being disabled. This was fixed.
+Currently, the driver does not support multiple CAN busses i.e. multiple CAN2USB devices. The fix for this is in the works...
 
 As this is experimental software, there might be other unknown issues.

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = mini-cheetah-motor-driver-socketcan
-version = 0.4.2
+version = 0.4.3
 author = Shubham Vyas
 author_email = [email protected]
 description = A Python Driver for MIT Mini-Cheetah Actuator which uses SocketCAN for communication.

src/motor_driver/canmotorlib.py

@@ -179,6 +179,8 @@ class CanMotorController:
     Class for creating a Mini-Cheetah Motor Controller over CAN. Uses SocketCAN driver for
     communication.
     """
+    can_socket_declared = False
+    motor_socket = None
 
     def __init__(self, can_socket="can0", motor_id=0x01, motor_type="AK80_6_V1p1", socket_timeout=0.05):
         """
@@ -210,16 +212,20 @@ def __init__(self, can_socket="can0", motor_id=0x01, motor_type="AK80_6_V1p1", s
 
         can_socket = (can_socket,)
         self.motor_id = motor_id
-        # create a raw socket and bind it to the given CAN interface
-        try:
-            self.motor_socket = socket.socket(socket.AF_CAN, socket.SOCK_RAW, socket.CAN_RAW)
-            self.motor_socket.setsockopt(socket.SOL_CAN_RAW, socket.CAN_RAW_LOOPBACK, 0)
-            self.motor_socket.bind(can_socket)
-            self.motor_socket.settimeout(socket_timeout)
-            print("Bound to: ", can_socket)
-        except Exception as e:
-            print("Unable to Connect to Socket Specified: ", can_socket)
-            print("Error:", e)
+        if not CanMotorController.can_socket_declared:
+            # create a raw socket and bind it to the given CAN interface
+            try:
+                CanMotorController.motor_socket = socket.socket(socket.AF_CAN, socket.SOCK_RAW, socket.CAN_RAW)
+                CanMotorController.motor_socket.setsockopt(socket.SOL_CAN_RAW, socket.CAN_RAW_LOOPBACK, 0)
+                CanMotorController.motor_socket.bind(can_socket)
+                CanMotorController.motor_socket.settimeout(socket_timeout)
+                print("Bound to: ", can_socket)
+                CanMotorController.can_socket_declared = True
+            except Exception as e:
+                print("Unable to Connect to Socket Specified: ", can_socket)
+                print("Error:", e)
+        elif CanMotorController.can_socket_declared:
+            print("Socket already available. Using:  ", CanMotorController.motor_socket)
 
         # Initialize the command BitArrays for performance optimization
         self._p_des_BitArray = BitArray(
@@ -241,7 +247,7 @@ def _send_can_frame(self, data):
         can_dlc = len(data)
         can_msg = struct.pack(can_frame_fmt_send, self.motor_id, can_dlc, data)
         try:
-            self.motor_socket.send(can_msg)
+            CanMotorController.motor_socket.send(can_msg)
         except Exception as e:
             print("Unable to Send CAN Frame.")
             print("Error: ", e)
@@ -252,7 +258,7 @@ def _recv_can_frame(self):
         """
         try:
             # The motor sends back only 6 bytes.
-            frame, addr = self.motor_socket.recvfrom(recvBytes)
+            frame, addr = CanMotorController.motor_socket.recvfrom(recvBytes)
             can_id, can_dlc, data = struct.unpack(can_frame_fmt_recv, frame)
             return can_id, can_dlc, data[:can_dlc]
         except Exception as e: