Drive robotic arm with a Gamepad from a Raspberry Pi with HTTP requests and ESP8266

rot2u 6dof http client espduino esp8266 evdev gamepad

# HTTP Client to drive Arduino Robotic kit (ROT2U 6DOF) with a Gamepad and a Raspberry Pi 3
# Client HTTP permettant de piloter un bras robotique (kit ROT2U 6DOF) avec un Gamepad depuis un Raspberry Pi 3
# https://projetsdiy.fr - https://diyprojects.io - dev. 2017
# Tutoriel complet https://projetsdiy.fr/piloter-bras-robotique-wifi-gamepad-raspberry-pi-python-evdev-requete-http/

import requests, time
from evdev import InputDevice, categorize, ecodes
from threading import Thread

# Adresse IP et point d entree de la requete HTTP sur l'ESP8266 | ESP8266 Http and end point
esp8266url = "http://192.168.1.65/cmd"

# cree un objet 'gamepad' attache au port USB | creates object 'gamepad' to store the data
# executer ls /dev/input pour cidentifier le port USB | execute the command ls /dev/input in a Terminal to find usb port
gamepad = InputDevice('/dev/input/event2')

# Gamepad connecte | prints out device info at start
print("Gamepad: ",gamepad)

# Variables globales permettant d actualiser la requete HTTP | Global variables to update HTTP thread
servo       = ""
direction   = ""
send        = False
httpFreq    = .050

aBtn = 289
bBtn = 290
xBtn = 288
yBtn = 291
lBtn = 292
rBtn = 293
selBtn = 296
staBtn = 297

# HTPP request thread
def sendRequest():
  global servo
  global direction
  global send
  while True:
    # Un seul servo a la fois pour le moment | Only one servo in the version
    payload = {
       servo:direction
    }
    # Envoi les ordres de deplacement jusqu a ce que send = false | Send HTTP request until send = False
    if send:
      r = requests.get(esp8266url, params=payload)
      print r.url
      print r.json
      time.sleep(httpFreq)

# Demarre le thread
t1 = Thread(target=sendRequest)
t1.start()

#evdev takes care of polling the controller in a loop
for event in gamepad.read_loop():
    print("Event: ",categorize(event)," |value: ",event.value)
    if event.type == ecodes.EV_KEY:
        print("button is pressed",categorize(event))
        if event.value == 1:
            if event.code == xBtn:
                servo = "servo2"
                direction = "up"
                send = True
                print("X")
            elif event.code == bBtn:
                servo = "servo2"
                direction = "down"
                send = True
                print("B")
            elif event.code == aBtn:
                servo = "servo3"
                direction = "up"
                send = True
                print("A")
            elif event.code == yBtn:
                servo = "servo3"
                direction = "down"
                send = True
                print("Y")
            elif event.code == lBtn:
                servo = "servo4"
                direction = "up"
                send = True
                print("LEFT BTN")
            elif event.code == rBtn:
                servo = "servo4"
                direction = "down"
                send = True
                print("RIGHT BTN")   
            elif event.code == selBtn:
                servo = "servo5"
                direction = "open"
                send = True
                print("Select BTN")
            elif event.code == staBtn:
                servo = "servo5"
                direction = "close"
                send = True
                print("Start BTN")     
        elif event.value == 0:
          send = False        
    elif event.type == ecodes.EV_ABS:
        absevent = categorize(event)
        print ecodes.bytype[absevent.event.type][absevent.event.code], absevent.event.value
        if ecodes.bytype[absevent.event.type][absevent.event.code] == "ABS_X":
             if absevent.event.value == 0:
                servo = "servo0"
                direction = "left"
                send = True
                print("Left")
             elif absevent.event.value == 255:
                servo = "servo0"
                direction = "right"
                send = True
                print("Right")
             elif absevent.event.value == 127:
                send = False
                   
        elif ecodes.bytype[absevent.event.type][absevent.event.code] == "ABS_Y":
             if absevent.event.value == 0:
                servo = "servo1"
                direction = "up"
                send = True
                print("Up")
             elif absevent.event.value == 255:
                servo = "servo1"
                direction = "down"
                send = True
                print("Down")
             elif absevent.event.value == 127:
                send = False