Update docs and instructions

README.md

@@ -75,6 +75,7 @@ DummyController echoes Motion messages to the terminal.
 ros2 run robot_controller dummy_controller
 ```
 
+### AxidrawController
 AxidrawController draws on the axidraw robot.
 Find the serial device in "/dev/", it is usually named "/dev/ttyACMX" where X is usually 0.
 Try a different serial port if the axidraw_controller continuously logs a message about failing to connect.
@@ -82,6 +83,7 @@ Try a different serial port if the axidraw_controller continuously logs a messag
 ros2 launch axidraw_controller axidraw_controller.launch.py serial_port:=/dev/ttyACM0 config:=./config.yaml
 ```
 
+### Lite6Controller
 This starts the simulated lite6
 ``` sh
 ros2 launch lite6_controller lite6_gazebo.launch.py config:=./config.yaml
@@ -97,6 +99,18 @@ This runs the real lite6 without Rviz (can be run on headless device over ssh)
 ros2 launch lite6_controller lite6_real_no_gui.launch.py config:=./config.yaml
 ```
 
+Before using the real lite6, it is recommended to run the calibration program.
+A lite6_controller must be running for calibration.
+This can be used to measure the Z height for a specific pen.
+The program also moves the arm to a known default position.
+``` sh
+ros2 run lite6_controller lite6_calibration
+```
+Follow the instructions, pressing enter when prompted.
+
+Change the Z-offset value accordingly.
+Restart the running lite6_controller after calibration.
+
 ### DrawingController
 Once a RobotController is running, simultaneously (using tmux or another terminal) run
 ``` sh

src/lite6_controller/src/lite6_calibration.cpp

@@ -58,7 +58,7 @@ int main(int argc, char **argv)
     client.init(node, hw_ns);
     client.motion_enable(true);
 
-    println("Setting xArm lite6 to free-drive mode. Attach pen and touch the drawing surface.");
+    println("Setting xArm lite6 to free-drive mode. Attach pen and touch the drawing surface. (You can also skip this if you do not want to measure Z)");
     client.set_mode(2);
     client.set_state(0);
     //rclcpp::sleep_for(std::chrono::seconds(20));
@@ -115,7 +115,7 @@ int main(int argc, char **argv)
     println("z-offset value for '" + ee_link + "' (use this value for the current pen): " + z);
 
 
-    println("Moving to start drawing pose");
+    println("WARNING. Moving to start drawing pose. Press ctrl-c to cancel");
     wait();
     client.set_servo_angle(jnt_drawing_pose, 1, 1, 1, true, 100, -1);
 
@@ -125,7 +125,7 @@ int main(int argc, char **argv)
 
     rclcpp::shutdown();
 
-    println("Done, ignore any errors after this");
+    println("Done, ignore any errors after this. Restart lite6_controller after I exit.");
     wait();
     return 0;
 }