Add sensor interface for user input PCB

Add sensor interface script to read and write data from user input PCB.

Author: nevalsar

CMakeLists.txt

@@ -51,6 +51,7 @@ find_package(catkin REQUIRED COMPONENTS
 add_message_files(
   FILES
   Weight.msg
+  UserInput.msg
 )
 
 ## Generate services in the 'srv' folder

msg/UserInput.msg

@@ -0,0 +1,3 @@
+Header header
+string ingredient
+int32 quantity

scripts/user_input_pcb.py

@@ -0,0 +1,79 @@
+#!/usr/bin/env python3
+import re
+import rospy
+import serial
+from std_msgs.msg import Bool
+
+from sensor_interface.msg import UserInput
+
+
+class UserInputInterface:
+    publisher = None
+    subscriber = None
+    dispensing_in_progress = False
+    serial = None
+    rate = None
+
+    def __init__(self, device="/dev/ttyACM0", publish_rate=500) -> None:
+        rospy.init_node("user_input_node")
+        self.publisher = rospy.Publisher("user_input", UserInput, queue_size=10)
+        self.subscriber = rospy.Subscriber(
+            "/dispensing_progress", Bool, self.update_dispensing_state
+        )
+        self.serial = serial.Serial(device, 9600, timeout=1)
+        self.rate = rospy.Rate(publish_rate)
+
+        # self.read_user_input()
+
+    def update_dispensing_state(self, progressMsg):
+        self.dispensing_in_progress = progressMsg.data
+        # print(self.dispensing_in_progress)
+        if self.dispensing_in_progress:
+            self.serial.write(b"t")
+        else:
+            self.serial.write(b"f")
+        # Serial Write to arduino
+
+    def read_user_input(self):
+        count = 0
+        while not rospy.is_shutdown():
+            line = self.serial.readline()  # read a '\n' terminated line
+            if type(line) is bytes:
+                data = line.decode("utf-8")
+                # print(f"Received = {data}")
+                # parsed_data = re.findall(r"[-+]?(?:\d*\.\d+|\d+)", data)
+                # print(f"Parsed = {parsed_data}")
+                if len(data) == 0:
+                    # rospy.logerr(
+                    #     f"Invalid value from sensor. Raw value received: {data}"
+                    # )
+                    # print("Stopping serial read")
+                    # break
+                    continue
+                # message pipeline to start dispensing
+                send_msg = UserInput()
+                send_msg.header.seq = count
+                send_msg.header.stamp = rospy.Time.now()
+                send_msg.ingredient = data[: data.index("#")]
+                send_msg.quantity = int(data[data.index("#") + 1 :])
+                # print(f"Name: {send_msg.ingredient}")
+                # print(f"Quantity: {send_msg.quantity}")
+
+                # write read input
+
+                # if parsed_data is of form
+                # self.dispensing_in_progress = True
+                count += 1
+                self.publisher.publish(send_msg)
+                self.rate.sleep()
+            else:
+                rospy.logwarn("Garbage value recieved from the weighing scale")
+
+
+if __name__ == "__main__":
+    try:
+        inputObj = UserInputInterface()
+        # inputObj.read_user_input(device=rospy.get_param('device'))
+        inputObj.read_user_input()
+    except rospy.ROSInterruptException:
+        pass

scripts/weighing_scale.py

@@ -9,7 +9,7 @@
 def read_weight(device="/dev/ttyUSB0", publish_rate=500):
     pub = rospy.Publisher("weighing_scale", Weight, queue_size=10)
     count = 0
-    rospy.init_node("weighing_scale", anonymous=True)
+    rospy.init_node("weighing_scale")
     rate = rospy.Rate(publish_rate)
     ser = serial.Serial(device, 9600, timeout=1)
     while not rospy.is_shutdown():