ScratchLink sample program

scratchlink.py

from websocket_server import WebsocketServer
import json
import base64
import time
from threading import Timer

connecting = False

def update(client,server):
    while connecting:
        print("sending {}->{}".format(client,server))
        b64 = base64.b64encode(bytes([0,123,1,0,1,1,1,1,1,1])).decode('utf-8')
        response = '{"jsonrpc":"2.0","method":"characteristicDidChange","params":{"serviceId":61445,"characteristicId":"5261da01-fa7e-42ab-850b-7c80220097cc","encoding":"base64","message":"' + b64 + '"}}'
        server.send_message(client, response)
        time.sleep(1)
    print("Update exited")

# Called for every client connecting (after handshake)
def new_client(client, server):
    print("New client connected and was given id %d" % client['id'])
    server.send_message_to_all("Hey all, a new client has joined us")

# Called for every client disconnecting
def client_left(client, server):
    global connecting
    print("Client(%d) disconnected" % client['id'])
    connecting = False

# Called when a client sends a message
def message_received(client, server, message):
    global connecting
    if len(message) > 200:
        message = message[:200]+'..'
    print("Client(%d) said: %s" % (client['id'], message))
    dict = json.loads(message)
    if dict['method'] == 'discover':
        id = dict['id']
        response = '{"jsonrpc":"2.0","id":'+str(id)+',"result":null}'
        server.send_message(client, response)
        response = '{"jsonrpc":"2.0","method":"didDiscoverPeripheral","params":{"name":"python","rssi":-70,"peripheralId":65536}}'
        server.send_message(client, response)
    if dict['method'] == 'connect':
        id = dict['id']
        response = '{"jsonrpc":"2.0","id":'+str(id)+',"result":null}'
        server.send_message(client, response)
    if dict['method'] == 'read':
        connecting = True
        timer = Timer(1, update, (client, server))
        timer.start()
    if dict['method'] == 'write':
        message = base64.b64decode(dict['params']['message'])
        if message[0] == 0x81:
            print('Say "'+message[1:].decode('utf-8')+'"')
        elif message[0] == 0x82:
            for x in list(message[1:]):
                print(format(x,"05b")[::-1])
        id = dict['id']
        response = '{"jsonrpc":"2.0","id":'+str(id)+',"result":null}'
        server.send_message(client, response)

PORT=20111
server = WebsocketServer(port = PORT)
server.set_fn_new_client(new_client)
server.set_fn_client_left(client_left)
server.set_fn_message_received(message_received)
server.run_forever()