uPy_Lewansoul_LX-16

This is a library specific to be used in MicroPython, especifically for the ESP32 and ESP8266. However, it should work in any other board with uPy that has uart ports. ( In the current commit it might just work in ESP32 since txbuf in the initialization of UART is used.)

This uPy script will be developed with the help of the following repository: https://github.com/maximkulkin/lewansoul-lx16a

I will only be adapting any function and constructors needed for a better use, similar to the Dynamixel library used by Robotis.

The file needed in which the class to control these servos is, is lx16.py. That is the file that should be included in you ESP to control the motor afterwards.

Hardware communication

The communication for this motor, is the same as the one in the following repository: AX12 MicroPython

There you can find what circuit was used. The harware is basically the same. The script is what changes in some way, but not that much

Methods

Here every method or action that can be done with the servo will be stated. These are divided in writing and reading methods. Have in mind that most of writing methods begin with set, also that they have been defined in such a way that it is easy to use them. Most of them are really similar to the ones found for Dynamixel in arduino in order to keep something similar.

In most of the methods, ID needs to be identified, which corresponds to the ID of the servo that is going to be modified or worked with. Also every method have the following parameters that already have a default value:

• rxbuf: defines the amount of bytes that are received from the servo, mostly useful for reading methods.
• rtime: defines the amount of time of microseconds that the microcontroller will wait once the packet has been sent to the servo, to start reading the returned packet.
• timeout: defines the amount of time that the microcontroller will wait for the servo to return a packet before it continues with the script. This is mostly useful to use with the method called goal_position since it takes time for the servo to turn. If it receives another action after that, it kinda crashes.

Writing methods

For the methods related to goal_position, the parameter timeout already has a default value of 2500, meaning that by default it would wait 2.5 seconds for the servo to get into position.

Method	Description
goal_position(ID, angle, time)	This method turn the servo to the specified angle in the specified time. The angle limits are between 0-240 degrees. And time goes from 0-30000 ms.
start_goal_position(ID, angle,time)	This is a special method, which needs the same as the last method to be defined. Does the same as the last method, however, it doesn't turn as soon as the method is executed unless the method start(ID) is executed as well. (Explained below)
start(ID)	Works as a trigger for every WAIT command that is used. Triggers the last saved action in the servo.
stop(ID)	Stops the servo immediately.
set_id(ID,NID)	Changes the ID of the servo, where NID corresponds to the new ID that want to be specified.
set_temp_offset_angle(ID,angle)	Adjusts the offset angle, isn't saved, meaning it is temporary, just while the servo is on. The angle range is -30~30 degrees. Also after it is executed, the servo will rotate the defined degrees as angle.
set_offset_angle(ID,angle)	This is the same as the last method, however, this one saves the angle specifed, even if the servo is shut downed.
set_angle_limit(ID,minangle,maxangle)	Sets the limit angle in which the servo can turn. Have in mind that minangle must be less than maxangle. Also that the angles mus be between 0~240 degrees.
set_vin_limit(ID,minvin,maxvin)	Defines a range of voltage in which the servo works. minvin must be less than maxvin. The voltage limits must be between 4500 - 12000 mv. In case the supplied voltage or Vin isn't in the specified range, the servo stops working.
set_max_temp_limit(ID,temp)	Defines the max temperature in which the servo will work. temp can take values from 50 to 100, specified in Celsius degrees. The default value is 85 degrees Celsius. The servo will flash the led if it reaches a higher value of temperature.
set_load_status(ID,status)	Defines whether the servo exerts torque or not. status can take values of 0 or 1. 1 represents the servo is loaded, it has a torque output. 0 is the default value which means unloaded.
set_led_ctrl(ID,mode)	Defines if the led is on/off. This is saved even if the servo is shutdowned. 0 is for always off, and 1 for always on.
set_led_error(ID,fault)	Sets the fault that will cause the LED flashing alarm. It can have value between 0~7.
goal_speed(ID,speed)	Puts the servo in a mode like a DC motor. Where speed takes values between 0~1000. 1000 being the maximum value. If it is defined as negative. It turns the other way.
joint_mode(ID)	Puts the servo in joint mode, meaning it is like a normal servo, that can be used with goal_position(angle,time) method. This is saved even if the servo is shutdowned.

Reading Methods

Method	Description
read_goal_position(ID)	Returns the last angle and time of turn requested.
read_wait_goal_position(ID)	Returns the goal position requested to wait.
read_id(ID)	Returns the ID of the servo.
read_angle_offset(ID)	Returns the offset angle.
read_angle_limit(ID)	Returns the angle limit.
read_vin_limit(ID)	Returns the voltage of input limits.
read_temp_max_limit(ID)	Returns the max temperature the Servo, degree Celsius.
read_temp(ID)	Returns the temperature of the servo.
read_vin(ID)	Returns the voltage input of the servo.
read_pos(ID)	Returns the current position of the servo.
read_servo_mode(ID)	Returns the mode of the servo.
read_load_status(ID)	Returns the load status of the servo.
read_led_ctrl(ID)	Returns the control of the led.
read_led_error(ID)	Returns the error of the led.

License

uPy_Lewansoul_LX-16 by Steven Silva is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Based on a work at https://github.com/FunPythonEC/uPy_Lewansoul_LX-16.