AP with multiple clients issue

[AppalachianWarrior]

Hi All.
First post here.

My project involves 3 Pico-Ws.
One of them is set up as an AP and the other 2 as Clients. We will call them Client # 1 and Client # 2.
Upon code execution, the AP Pico sends the current time data to both clients.
Ideally, both clients receive the current time data and set the Real Time Clock modules attached to them. Job is done.

Here is the issue:
When I run the AP code, 60% of the time, it runs fine and both clients receive the data and life is good. Both clients have an 'Output type 1'.
( Please see the end of this post below for the 3 types of output )

The other 25% of the times that I run the AP code, Client # 1 produces an 'Output type 1' and Client # 2 produces and 'Output type 3'.
The other 15% of the times that I run the AP code, Client # 1 produces an 'Output type 2' and Client # 2 produces and 'Output type 3'.
( I use Thonny. I click 'run' on the AP code, then 'run' on Client # 1's code and then 'run' on Client # 2's code; in that sequence )

I tried resetting the Pico-W before running code each time but that doesn't seem to help.
I tried putting a pause in the AP's code but that didn't help.
I did a ton of other things but this random behavior keeps popping up.

My reading online tells me that 'Output type # 3' happens due to the connection being forcibly closed by the remote host. This Output type # 3 can also mean that the AP is overloaded or misconfigured, which causes it to drop connections. It just probably cant handle multiple simultaneous connections properly.

When I have just a single client, I never have any issues and the output is always 'Output type 1'.

Can someone please give me feedback on whats going on?
Ty for the replies!

Output type 1.
MPY: soft reboot
Checking for Network: Switch_LED
Connecting to Network...
IP: 192.168.10.3
Ready
Connected to AP
Received the following date and time from the AP: 33 30 20 11 26 06 2024 4
The time has been set to 2024-06-26 11:20:30 AM
Day of the week: Wednesday
Disconnected from Network.

Output type 2.
MPY: soft reboot
Checking for Network: Switch_LED
Network not found...
Disconnected from Network.
All received messages: []

Output type 3.
MPY: soft reboot
Checking for Network: Switch_LED
Connecting to Network...
IP: 192.168.10.4
Ready
Socket error: [Errno 104] ECONNRESET
Socket error: [Errno 104] ECONNRESET
Socket error: [Errno 104] ECONNRESET
Failed to connect after 3 retries.
Disconnected from Network.
All received messages: []

AP CODE below:

import network
import socket
import utime

server_ip = '192.168.10.1'
gateway_ip = '192.168.10.1'
port = 5263
ssid = 'Switch_LED'
password = '2468013579'

wlan = network.WLAN(network.AP_IF)
wlan.active(True)
wlan.config(essid=ssid, password=password)
wlan.ifconfig((server_ip, '255.255.255.0', gateway_ip, '8.8.8.8'))

server_sock = socket.socket()

try:
    server_sock.bind((server_ip, port))
    server_sock.listen(15)
    print(f'Server listening on {server_ip}:{port}')
    
    while True:
        client_sock, client_addr = server_sock.accept()
        print(f'Client connected from {client_addr}')
        
        # Handle client communication here
        try:
            data = client_sock.recv(1024)
            if data:
                print(f'Received data from {client_addr}: {data.decode()}')
                # Get current time and format it
                current_time = utime.localtime()
                
          # Must set the time in message_to_send in this format!!!: hundredths, seconds, minutes, hours, date, month, year, day_of_week
          # Example: June 20, 2024, 20:20:45.50 (hundredths: 50), Thursday (day_of_week: 4). Week begins on Mon , not Sun!
                
                message_to_send = f"33 30 20 11 26 06 2024 4"
                client_sock.send(message_to_send.encode())
                print(f'Sent the following message to the client at {client_addr}: {message_to_send}')
        except Exception as e:
            print(f'Error processing client data: {e}')
        
        # Close client socket
        client_sock.close()
        print(f'Client {client_addr} disconnected')
        print(f'   ')
except KeyboardInterrupt:
    print('Server stopped by user')
except Exception as e:
    print(f'Error occurred: {e}')
finally:
    if server_sock:
        server_sock.close()
    wlan.active(False)

Client # 1 code below:

#RemoteSetTime-Client-A.py
import network
import socket
import time
from machine import Pin, I2C
from rv1805 import RV1805  # Assuming you have the RV1805 RTC class implemented

host = '192.168.10.3'  # Assuming Device B's IP (must be unique in the subnet)
serverAP = '192.168.10.1'
gatewayAP = '192.168.10.1'
port = 5263

ssid = 'Switch_LED'
pw = '2468013579'  # Password needs to be 8 characters or more

wlan = network.WLAN(network.STA_IF)
wlan.active(True)

Onboard_LED = Pin("LED", Pin.OUT, value=0)

# Initialize I2C interface with SCL on GPIO9 and SDA on GPIO8
i2c = I2C(0, scl=Pin(9), sda=Pin(8))

# Initialize RV1805 RTC
rtc = RV1805(i2c)

# Function to convert decimal to BCD
def dec_to_bcd(val):
    return (val // 10) << 4 | (val % 10)

# Function to convert BCD to decimal
def bcd_to_dec(val):
    return (val >> 4) * 10 + (val & 0x0F)

# Function to set time on RV1805
def set_time(hund, sec, min, hour, date, month, year, day):
    rtc.writeRegister(RV1805.RV1805_HUNDREDTHS, dec_to_bcd(hund))
    rtc.writeRegister(RV1805.RV1805_SECONDS, dec_to_bcd(sec))
    rtc.writeRegister(RV1805.RV1805_MINUTES, dec_to_bcd(min))
    rtc.writeRegister(RV1805.RV1805_HOURS, dec_to_bcd(hour))
    rtc.writeRegister(RV1805.RV1805_DATE, dec_to_bcd(date))
    rtc.writeRegister(RV1805.RV1805_MONTHS, dec_to_bcd(month))
    rtc.writeRegister(RV1805.RV1805_YEARS, dec_to_bcd(year))
    rtc.writeRegister(RV1805.RV1805_WEEKDAYS, dec_to_bcd(day))
    
    # Calculate day of the week (0 = Sunday, 6 = Saturday)
    # Adjusted calculation to match desired input where 0=Sunday, 1=Monday, ..., 6=Saturday
    day_of_week = (day + 6) % 7

    # Define weekday names
    weekdays = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"]

    # Print the set time in a readable format
    am_pm = "AM" if hour < 12 else "PM"
    hour_12 = hour % 12
    hour_12 = 12 if hour_12 == 0 else hour_12
    print(f"The time has been set to {year:02}-{month:02}-{date:02} {hour_12:02}:{min:02}:{sec:02} {am_pm}")
    print(f"Day of the week: {weekdays[day_of_week]}")

# Function to check if AP (Switch_LED) is available
def check_SSID():
    print('Checking for Network:', ssid)
    networks = wlan.scan()
    found = False
    for w in networks:
        if w[0].decode() == ssid:
            found = True
    return found

# Function to handle connection failures
def connect_Fail(s):
    errors = {
        0: 'Link Down',
        1: 'Link Join',
        2: 'Link NoIP',
        -1: 'Link Fail',
        -2: 'NoNet',
        -3: 'BadAuth'
    }
    error_msg = 'Connect Fail: ' + errors.get(s, 'Unknown')
    print(error_msg)

# Function to connect to the network
def connect_to_network():
    try:
        if check_SSID():
            print('Connecting to Network...')
            wlan.active(True)
            wlan.config(pm=0xa11140)  # Disable power-save mode
            wlan.connect(ssid, pw)
            while not wlan.isconnected():
                time.sleep(1)
            status = wlan.status()
            if status == 3:
                # Set IP address to the network we want, otherwise it uses 192.168.4.XXX
                wlan.ifconfig((host, '255.255.255.0', gatewayAP, '8.8.8.8'))
                status = wlan.ifconfig()
                print('IP:', status[0])
                return True
            else:
                connect_Fail(status)
                print('Cannot connect...')
                return False
        else:
            print('Network not found...')
            return False
    except Exception as e:
        print('Error occurred:', e)
        return False

# Function to print current RTC datetime
def print_current_datetime():
    hund = bcd_to_dec(rtc.readRegister(RV1805.RV1805_HUNDREDTHS))
    sec = bcd_to_dec(rtc.readRegister(RV1805.RV1805_SECONDS))
    min = bcd_to_dec(rtc.readRegister(RV1805.RV1805_MINUTES))
    hour = bcd_to_dec(rtc.readRegister(RV1805.RV1805_HOURS))
    date = bcd_to_dec(rtc.readRegister(RV1805.RV1805_DATE))
    month = bcd_to_dec(rtc.readRegister(RV1805.RV1805_MONTHS))
    year = bcd_to_dec(rtc.readRegister(RV1805.RV1805_YEARS))
    day = bcd_to_dec(rtc.readRegister(RV1805.RV1805_WEEKDAYS))

    # Calculate day of the week (0 = Sunday, 6 = Saturday)
    # Adjusted calculation to match desired input where 0=Sunday, 1=Monday, ..., 6=Saturday
    day_of_week = (day + 6) % 7

    # Define weekday names
    weekdays = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"]

    # Print the current datetime in a readable format
    am_pm = "AM" if hour < 12 else "PM"
    hour_12 = hour % 12
    hour_12 = 12 if hour_12 == 0 else hour_12
    print(f"Current datetime: 20{year:02}-{month:02}-{date:02} {weekdays[day_of_week]}, {hour_12:02}:{min:02}:{sec:02}.{hund:02} {am_pm}")

# Main program execution
Onboard_LED.on()
received_messages = []
rtc_set = False

try:
    if connect_to_network():
        print('Ready')
        while not rtc_set:
            s = socket.socket()
            try:
                s.connect((serverAP, port))
                print('Connected to AP')
                s.send(b'Hello from Client A!')
                response = s.recv(1024)
                message = response.decode()
                print('Received the following date and time from the AP:', message)
                received_messages.append(message)
                
                # Set RTC time from received data
                hund, sec, min, hour, date, month, year, day_of_week = message.split()
                set_time(int(hund), int(sec), int(min), int(hour), int(date), int(month), int(year), int(day_of_week))
                
                # Set flag to indicate RTC time is set
                rtc_set = True

            except OSError as e:
                print('Socket error:', e)
            finally:
                s.close()
                #time.sleep(2)  # Adjust timing as needed

        # Print current RTC time every 2 seconds
        while True:
            print_current_datetime()
            time.sleep(15)

except Exception as e:
    print('Error occurred:', e)
finally:
    wlan.disconnect()
    wlan.active(False)
    print('Disconnected from Network.')
    Onboard_LED.off()

print('All received messages:', received_messages)

Client # 2 code below:

#RemoteSetTime-Client-B.py
import network
import socket
import time
from machine import Pin, I2C
from rv1805 import RV1805  # Assuming you have the RV1805 RTC class implemented

host = '192.168.10.4'  # Assuming Device B's IP (must be unique in the subnet)
serverAP = '192.168.10.1'
gatewayAP = '192.168.10.1'
port = 5263

ssid = 'Switch_LED'
pw = '2468013579'  # Password needs to be 8 characters or more

wlan = network.WLAN(network.STA_IF)
wlan.active(True)

Onboard_LED = Pin("LED", Pin.OUT, value=0)

# Initialize I2C interface with SCL on GPIO9 and SDA on GPIO8
i2c = I2C(0, scl=Pin(9), sda=Pin(8))

# Initialize RV1805 RTC
rtc = RV1805(i2c)

# Function to convert decimal to BCD
def dec_to_bcd(val):
    return (val // 10) << 4 | (val % 10)

# Function to convert BCD to decimal
def bcd_to_dec(val):
    return (val >> 4) * 10 + (val & 0x0F)

# Function to set time on RV1805
def set_time(hund, sec, min, hour, date, month, year, day):
    rtc.writeRegister(RV1805.RV1805_HUNDREDTHS, dec_to_bcd(hund))
    rtc.writeRegister(RV1805.RV1805_SECONDS, dec_to_bcd(sec))
    rtc.writeRegister(RV1805.RV1805_MINUTES, dec_to_bcd(min))
    rtc.writeRegister(RV1805.RV1805_HOURS, dec_to_bcd(hour))
    rtc.writeRegister(RV1805.RV1805_DATE, dec_to_bcd(date))
    rtc.writeRegister(RV1805.RV1805_MONTHS, dec_to_bcd(month))
    rtc.writeRegister(RV1805.RV1805_YEARS, dec_to_bcd(year))
    rtc.writeRegister(RV1805.RV1805_WEEKDAYS, dec_to_bcd(day))
    
    # Calculate day of the week (0 = Sunday, 6 = Saturday)
    # Adjusted calculation to match desired input where 0=Sunday, 1=Monday, ..., 6=Saturday
    day_of_week = (day + 6) % 7

    # Define weekday names
    weekdays = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"]

    # Print the set time in a readable format
    am_pm = "AM" if hour < 12 else "PM"
    hour_12 = hour % 12
    hour_12 = 12 if hour_12 == 0 else hour_12
    print(f"The time has been set to {year:02}-{month:02}-{date:02} {hour_12:02}:{min:02}:{sec:02} {am_pm}")
    print(f"Day of the week: {weekdays[day_of_week]}")

# Function to check if AP (Switch_LED) is available
def check_SSID():
    print('Checking for Network:', ssid)
    networks = wlan.scan()
    found = False
    for w in networks:
        if w[0].decode() == ssid:
            found = True
    return found

# Function to handle connection failures
def connect_Fail(s):
    errors = {
        0: 'Link Down',
        1: 'Link Join',
        2: 'Link NoIP',
        -1: 'Link Fail',
        -2: 'NoNet',
        -3: 'BadAuth'
    }
    error_msg = 'Connect Fail: ' + errors.get(s, 'Unknown')
    print(error_msg)

# Function to connect to the network
def connect_to_network():
    try:
        if check_SSID():
            print('Connecting to Network...')
            wlan.active(True)
            wlan.config(pm=0xa11140)  # Disable power-save mode
            wlan.connect(ssid, pw)
            while not wlan.isconnected():
                time.sleep(1)
            status = wlan.status()
            if status == 3:
                # Set IP address to the network we want, otherwise it uses 192.168.4.XXX
                wlan.ifconfig((host, '255.255.255.0', gatewayAP, '8.8.8.8'))
                status = wlan.ifconfig()
                print('IP:', status[0])
                return True
            else:
                connect_Fail(status)
                print('Cannot connect...')
                return False
        else:
            print('Network not found...')
            return False
    except Exception as e:
        print('Error occurred:', e)
        return False

# Function to print current RTC datetime
def print_current_datetime():
    hund = bcd_to_dec(rtc.readRegister(RV1805.RV1805_HUNDREDTHS))
    sec = bcd_to_dec(rtc.readRegister(RV1805.RV1805_SECONDS))
    min = bcd_to_dec(rtc.readRegister(RV1805.RV1805_MINUTES))
    hour = bcd_to_dec(rtc.readRegister(RV1805.RV1805_HOURS))
    date = bcd_to_dec(rtc.readRegister(RV1805.RV1805_DATE))
    month = bcd_to_dec(rtc.readRegister(RV1805.RV1805_MONTHS))
    year = bcd_to_dec(rtc.readRegister(RV1805.RV1805_YEARS))
    day = bcd_to_dec(rtc.readRegister(RV1805.RV1805_WEEKDAYS))

    # Calculate day of the week (0 = Sunday, 6 = Saturday)
    # Adjusted calculation to match desired input where 0=Sunday, 1=Monday, ..., 6=Saturday
    day_of_week = (day + 6) % 7

    # Define weekday names
    weekdays = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"]

    # Print the current datetime in a readable format
    am_pm = "AM" if hour < 12 else "PM"
    hour_12 = hour % 12
    hour_12 = 12 if hour_12 == 0 else hour_12
    print(f"Current datetime: 20{year:02}-{month:02}-{date:02} {weekdays[day_of_week]}, {hour_12:02}:{min:02}:{sec:02}.{hund:02} {am_pm}")

# Main program execution
Onboard_LED.on()
received_messages = []
rtc_set = False

try:
    if connect_to_network():
        print('Ready')
        while not rtc_set:
            s = socket.socket()
            try:
                s.connect((serverAP, port))
                print('Connected to AP')
                s.send(b'Hello from Client B!')
                response = s.recv(1024)
                message = response.decode()
                print('Received the following date and time from the AP:', message)
                received_messages.append(message)
                
                # Set RTC time from received data
                hund, sec, min, hour, date, month, year, day_of_week = message.split()
                set_time(int(hund), int(sec), int(min), int(hour), int(date), int(month), int(year), int(day_of_week))
                
                # Set flag to indicate RTC time is set
                rtc_set = True

            except OSError as e:
                print('Socket error:', e)
            finally:
                s.close()
                time.sleep(2)  # Adjust timing as needed

        # Print current RTC time every 2 seconds
        while True:
            print_current_datetime()
            time.sleep(2)

except Exception as e:
    print('Error occurred:', e)
finally:
    wlan.disconnect()
    wlan.active(False)
    print('Disconnected from Network.')
    Onboard_LED.off()

print('All received messages:', received_messages)

[rkompass]

Of course Wifi connections are not perfectly reliable.

One other thing that comes to mind: Could it be that there is interaction of the Wifi protocols between the AP and clients 1 and 2?
I.e. do client 1 and 2 compete for access to the AP?
This you could test by comparing the probabilities (relative frequencies) of the outcomes of type 2 and 3 with client 1 or 2 alone versus
the probabilities when both try to connect simultaneously.

If these are different then there might be a way to de-synchronize their activities somehow...

[sophiedegran]

It can be to a problem of close socket..
You say it's 60% ok but random .. but the first time did it's 100% ok ?
(remenber by default you can open 10 sockets maximum)
I experiment that if the server close the socket it's ok (after a little timeout)... but if the client close first (because of trouble.. etc..), the server make lot's of time to close..
I resolve that using asyncio streamreader and streamwriter and wait_closed()

[AppalachianWarrior]

Hi Ty. Yes, the first few times this error did not show up. Seems like the more I used this code, the more it happens.

[sophiedegran]

Ok so try using async with StreamReader and StreamWriter
close each stream with wait_closed()
Peter async examples are there:
github.com/peterhinch/micropython-async/blob/master/v3/as_drivers/client_server

[glenn20]

I note that Output 2 seems to indicate the the wifi scan failed to find the ssid. However, this does not necessarily mean that a connect() would have failed.

It would be better to skip the check_SSID() and simplify your connect_to_network() code.

Also, a note that wlan.config(pm=0xa11140) # Disable power-save mode does not in fact disable power save mode, wlan.config(pm=wlan.PM_NONE) should do that.