1.2 How ws_test.py Works?

The communication between Pico and Sunfounder Controller is based on the websocket protocol.

The specific workflow of APP Control gameplay is as follows:

flowchart_app_control

from ws import WS_Server
import json
import time

NAME = 'my_esp8266'

## Client Mode
# WIFI_MODE = "sta"
# SSID = "YOUR SSID HERE"
# PASSWORD = "YOUR PASSWORD HERE"

## AP Mode
WIFI_MODE = "ap"
SSID = ""
PASSWORD = "12345678"


ws = WS_Server(name=NAME, mode=WIFI_MODE, ssid=SSID, password=PASSWORD)
ws.start()

led = machine.PWM(machine.Pin(15))
led.freq(1000)
potentiometer = machine.ADC(28)

def on_receive(data):
    print(data)

    # output
    value = data['H']
    led.duty_u16(value*655)

    # input
    value=potentiometer.read_u16()
    ws.send_dict['G'] = value

ws.on_receive = on_receive

def main():
    print("start")
    while True:
        ws.loop()

main()

This code constitutes the basic framework of APP control. Here, you need to pay attention to the following two parts:

  1. Setup websocket

    There are two connection mode between Sunfounder Controller and Pico: One is AP mode, the other is STA mode.

    • AP Mode: You need to connect Sunfounder Contorller to the hotspot released by pico.

    • STA Mode: You need to connect Sunfounder Controller and pico to the same LAN.

    The default connection mode is AP Mode: The Pico releases the hotspot (the Wifi name is NAME in the code, here is my_esp8266), the mobile phone (tablet) is connected to this WLAN. This mode allows you to remotely control pico in any situation, but will make your phone (tablet) temporarily unable to connect to the Internet.

    NAME = 'my_esp8266'
    
    ## Client Mode
    # WIFI_MODE = "sta"
    # SSID = "YOUR SSID HERE"
    # PASSWORD = "YOUR PASSWORD HERE"
    
    ## AP Mode
    WIFI_MODE = "ap"
    SSID = ""
    PASSWORD = "12345678"
    
    ws = WS_Server(name=NAME, mode=WIFI_MODE, ssid=SSID, password=PASSWORD)
    ws.start()
    

    You can also use STA mode: Let the pico connects to your home WLAN, and your mobile phone (tablet) should also be connected to the same WLAN.

    This mode is opposite to the AP mode and will not affect the normal use of the mobile phone (tablet), but will limit your pico from leaving the WLAN radiation range.

    The way to start this mode is to comment out the three lines under ## AP Mode, uncomment the three lines under ## Client Mode, and change the SSID and PASSWORD to your home WIFI at the same time.

    NAME = 'my_esp8266'
    
    ## Client Mode
    WIFI_MODE = "sta"
    SSID = "YOUR SSID HERE"
    PASSWORD = "YOUR PASSWORD HERE"
    
    ## AP Mode
    # WIFI_MODE = "ap"
    # SSID = ""
    # PASSWORD = "12345678"
    
    ws = WS_Server(name=NAME, mode=WIFI_MODE, ssid=SSID, password=PASSWORD)
    ws.start()
    

    After completing the connection mode settings, Websocket will set up and start the server.

    ws = WS_Server(name=NAME, mode=WIFI_MODE, ssid=SSID, password=PASSWORD)
    ws.start()
    
  2. Responding

    The specific operation code of Pico and Sunfounder Controller is written on the on_receive() function. Usually, we need to write the codes for APP to control Pico on the front and the codes for APP to show Pico sensor data on the back.

    def on_receive(data):
        print(data)
    
        # output
        value = data['H']
        led.duty_u16(value*655)
    
        # input
        value=potentiometer.read_u16()
        ws.send_dict['G'] = value
    
    ws.on_receive = on_receive
    

    Finally, on_receive() will be assigned to ws.on_receive and then called by ws.loop.