python_do_single_leg.rst

Adjust Posture

In this example, we use the keyboard to control the PiCrawler foot by foot and assume the desired posture.

You can press the space bar to print out the current coordinate values. These coordinate values come in handy when you create unique actions for PiCrawler.

Run the Code

cd /home/pi/picrawler/examples
sudo python3 do_single_leg.py

After the code runs, please operate according to the prompt that pops up in the terminal.

• Press 1234 to select the feet separately, 1: right front foot, 2: left front foot, 3: left rear foot, 4: right rear foot
• Press w, a, s, d, r, and f to slowly control the PiCrawler's coordinate values.
• Press space to print all coordinate values.
• Press esc to exit.

Code

from picrawler import Picrawler
from time import sleep
import readchar

crawler = Picrawler([10,11,12,4,5,6,1,2,3,7,8,9]) 
speed = 80


manual = '''
-------- PiCrawler Controller --------- 
    .......          .......
    <=|   2   |┌-┌┐┌┐-┐|   1   |=>
    ``````` ├      ┤ ```````
    ....... ├      ┤ .......
    <=|   3   |└------┘|   4   |=>
    ```````          ```````
    1: Select right front leg
    2: Select left front leg
    3: Select left rear leg
    4: Select right rear leg
    W: Y++          R: Z++             
    A: X--          F: Z--
    S: Y--
    D: X++          Esc: Quit
'''
legs_list = ['right front', 'left front', 'left rear', 'right rear']

def main():  
    leg = 0
    speed = 80
    step = 2
    print(manual)
    crawler.do_step('stand',speed)
    sleep(0.2)
    coordinate=crawler.current_step_all_leg_value()  

    def show_info():
        print("\033[H\033[J",end='')  # clear terminal windows
        print(manual)   
        print('%s : %s'%(leg+1, legs_list[leg])) 
        print('coordinate: %s'%(coordinate))  

    show_info()

    while True:
        # readkey
        key = readchar.readkey()
        key = key.lower()
        # select the leg 
        if key in ('1234'):
            leg = int(key) - 1
            show_info()
        # move
        elif key in ('wsadrf'):         
            if 'w' == key:
                coordinate[leg][1]=coordinate[leg][1] + step    
            elif 's' == key:
                coordinate[leg][1]=coordinate[leg][1] - step           
            elif 'a' == key:
                coordinate[leg][0]=coordinate[leg][0] - step         
            elif 'd' == key:
                coordinate[leg][0]=coordinate[leg][0] + step   
            elif 'r' == key:
                coordinate[leg][2]=coordinate[leg][2] + step         
            elif 'f' == key:
                coordinate[leg][2]=coordinate[leg][2] - step 

            crawler.do_single_leg(leg,coordinate[leg],speed) 
            sleep(0.1)  
            # coordinate=crawler.current_step_all_leg_value()
            show_info()
        # quit 
        elif key == readchar.key.CTRL_C or key in readchar.key.ESCAPE_SEQUENCES:
            print("\n Quit")  
            break    

        sleep(0.05)


if __name__ == "__main__":
    main()

• current_step_all_leg_value() : Returns the coordinate values of all legs.
• do_single_leg(leg,coordinate,speed) : Modify the coordinate value of a certain leg individually.