HW-MS03 Microwave sensor need help with syntax while/else

[marinehm]

Having trouble with While Else statement

# MicroPython v1.19.1 on 2022-06-18; Raspberry Pi Pico with RP2040
# Thonny 4.0.2
# HW-MS03 Microwave motion sensor
# Created by Nick Sebring
# 01-24-2023
##################################################################
# IMPORT NECESSARY MODULES
from machine import Pin
from time import sleep
import utime
# ASSIGN PINS
led = Pin(6, Pin.OUT)
hw = Pin(8, Pin.IN)
`# MAKE THINGS HAPPEN`
while hw==0:
#     hw==0:  #light stays on regardless
#     hw==1:  #light stays on regardless
#     hw!=0:  #prints "Scaning..." FOREVER!
#     hw!=1:  #prints "Scaning..." FOREVER!
  led.off()
  print("Scanning...")
  sleep(5)  #gives me time to figure what's going on
else:
  led.on()
  print("Motion detected!")
  sleep(5)   #gives me time to figure what's going on  
#What I expect; if after 5 seconds of no motion, the led to turn off
#But, if the motion detector remains high, then the led will remain on
#until the sensor goes LOW (0)'''

[davefes]

my_pin = hw.value()
Then test my_pin

while my_pin == 0:

[robert-hh]

@marinehm About formatting: When adding code, either enclose the code in lines containing three backticks ``` or indent the code lines by like four spaces. An easy way to get the 3 backtick lines is to fully highlight the pasted code and push Ctrl-E.

[sosi-deadeye]

I'm uncertain if this works (not tested).
You could use a combination of Pin.irq and Timer.

Here the code:

from machine import Pin
from machine import Timer


class Motion:
    def __init__(self, motion_pin, led_pin, off_delay):
        # motion_pin, not motion
        self.motion = Pin(motion_pin, mode=Pin.IN)
        self.led = Pin(led_pin, mode=Pin.OUT, value=0)
        self.off_delay = off_delay
        self.timer = None
        self.motion.irq(
            handler=self._callback,
            trigger=Pin.IRQ_FALLING | Pin.IRQ_RISING,
        )
    
    def _callback(self, pin):
        if self.timer:
            self.timer.deinit()
            self.timer = None
            
        if pin.value():
            self.led.value(1)
        else:
            # This should start the Timer
            # if your port does not support software timers,
            # then use a positive ID for initialization 
            self.timer = Timer(
                -1,
                mode=Timer.ONE_SHOT,
                period=self.off_delay,
                callback=self._no_motion,
            )
    
    def _no_motion(self, timer):
        self.led.value(0)



motion1 = Motion(motion_pin=8, led_pin=6, off_delay=5_000)

The irq watches both edges (falling and rising). I guess if motion is detected, the self.led should turn on. A rising edge is an input change from 0 to 1. This should switch the self.led on. The falling edge should turn the self.led off after 5 seconds (5_000 ms). A ONE_SHOT Timer with a callback is started. So if the input changes from 1 to 0, then the Timer is created, which calls after 5 seconds the _no_motion method. If during this period a rising edge happens, the self.timer.deinit() is called, to stop the Timer object. Then None is assigned to self.timer. I do not know, if you can reuse Timers. I think not.

[marinehm]

This is what I get when run:

  File "<stdin>", line 39, in <module>
  File "<stdin>", line 7, in __init__
NameError: name 'motion' isn't defined

[sosi-deadeye]

Easy fix

# change
self.motion = Pin(motion, mode=Pin.IN)
# to
self.motion = Pin(motion_pin, mode=Pin.IN)

[marinehm]

The longer the wire, the more "collective?", the light stays on..... More investigation!

[marinehm]

# MicroPython v1.19.1 on 2022-06-18; Raspberry Pi Pico with RP2040
# Thonny 4.0.2
# HW-MS03 Microwave motion sensor
# Created by Nick Sebring
# 01-24-2023
##################################################################

# IMPORT NECESSARY MODULES
from machine import Pin
from time import sleep
import utime

# ASSIGN PINS
led = Pin(6, Pin.OUT)
hw = Pin(8, Pin.IN)
my_pin = hw.value()

# MAKE THINGS HAPPEN
while True:
  if my_pin == 0:
#     my_pin ==0:    prints "Scanning..." FOREVER!
#     my_pin !=0:    prints "Motion detected!" FOREVER!
#     my_pin == 1:   prints "Scanning..." FOREVER!
#     my_pin != 1:   prints "Motion detected!" FOREVER!
    led.off()
    print("Scanning...")
    sleep(5)   #gives me time to figure what's going on
  else:
    led.on()
    print("Motion detected!")
    sleep(5)   #gives me time to figure what's going on

I just noticed; each time I run it, it toggles whether the led is on or off. WHAT THE HECK!?
Not like what is commented out.

[karfas]

What do you expect ?

You are setting my_pin to the input value and don't change it during the while True loop.

[marinehm]

I like the ctrl E
I'm used to the <> from the Arduino forum, paste the code between < code here >
OK, got it thanks!

[peterhinch]

As a general point it is rarely necessary to write while else. Referring to the above code, the following behaves identically:

while hw == 0:
    # do stuff
led.on()  # No need for else
print("motion detected")

The else clause is rather specialised. It runs if the while loop exits normally. It does not run if it exits via break, return or via an exception being thrown.

[davefes]

Suggestion: use 4 spaces to indent.

Also, I would either define your pin as a PULL_UP or put a 10K resistor from it to 3V3 to properly define it's operating state.

[marinehm]

I do use a resister on all my LEDs.

[bixb922]

If you want to test the input pin every 5 seconds, you need to test hw.value() within the while loop. You are testing the pin only once at the beginning before the loop, is that as intended?

[marinehm]

Copying my Arduino sketch that works flawlessly. I just want to learn micropython and play with some new Raspberry Pi Picos.

/*
Microwave Motion Sensor
LOLIN (WEMOS) Mini-D Pro
HW-MS03 Microwave motion sensor
1000uf 25V Capacitor
Lolin Relay

Capacitor across the  +  -

Senses motion from front and back of the PCB.  Not so much from the sides.
This even worked through a fairly thick plastic table that I used as a barrier.

By Nick Senring; 12-16-2022
*/

int HWPin = 16;
int Relay = 14;
int val;                          // This is the value from the HW-MS03 Microwave motion sensor

void setup()
{
  Serial.begin(9600);
  pinMode(HWPin, INPUT);          // HW-MS03 Microwave motion sensor
  pinMode(BUILTIN_LED, OUTPUT);   // BLUE LED onboard as OUTPUT (High/LOW is inverted)
  pinMode(Relay, OUTPUT);
}
void loop()
{
  val = digitalRead(HWPin);
  //low = no motion, high = motion
  if (val == HIGH)
  {
    Serial.println("Motion detected.  ");
    digitalWrite(BUILTIN_LED, LOW);
    digitalWrite(Relay, HIGH);  //Turn something on
    delay(30000); //   5000= 5 sec   300000= 5min, 600000= 10 min
    //  Keep it on for a period of time  //
  }

  else
  {
    Serial.println("Scanning...");
    digitalWrite(BUILTIN_LED, HIGH);
    digitalWrite(Relay, LOW);  //Turn something off
  }
}

[marinehm]

This doesn't work either:

# MicroPython v1.19.1 on 2022-06-18; Raspberry Pi Pico with RP2040
# Thonny 4.0.2
# HW-MS03 Microwave motion sensor
# Created by Nick Sebring
# 01-24-2023
##################################################################

# IMPORT NECESSARY MODULES
from machine import Pin
from time import sleep
import utime

# ASSIGN PINS
led = Pin(6, Pin.OUT)
hw = Pin(8, Pin.IN, Pin.PULL_DOWN)
#my_pin = hw.value()
led.off()


# MAKE THINGS HAPPEN
while True:
  while hw==high: # IS THIS HOW TO CHECK THE HW PIN(8) HIGH/LOW?   **Similar to "digital read" in Arduino?**
    # do stuff
    led.on()  # No need for else
    print("motion detected")
    sleep(5) # So I can see what's going on until it works correctly

    led.off()  # HOW ELSE IS THE LIGHT GOING TO TURN OFF?
    print("Scanning...")
    sleep(2)

[davefes]

Nope! Added a break. I was too focused on "getting into the loop".

[marinehm]

That code just toggled the LED on/off. for the amount of time on the "sleep".

THE Microwave sensor is either 0 or 1 rather; high / low.

Not sure how to "read" the Pin in Mycropython to get the value from Pin 8
Would this need an ADC?

No. I only want the LED to come on when the Sensor detects motion and set the pin high. Stay on for a specified amount of time. If it is still high, will run again for the specified time until it no longer detects motion. When the sensor goes low and the code runs again after the sleep, I want the LED to be turned off.

Please see my Arduino code above. It works flawlessly So, why am I doing this? To learn Micropython.

[marinehm]

So I did this:
It works but, I pretty much have to touch the sensor. Unlike on my ESP8266 with Arduino.IDE, it senses from over 7 feet and through my plastic folding table. What could make that difference?
And if you noticed... I changed LED pin to 3. Pin 6 stopped working. Afterward, I think with my failing eyesight, I plugged the wire into the wrong hole. Hahaha That's what she said! 3 is working

# IMPORT NECESSARY MODULES
from machine import Pin
from time import sleep
import utime

# ASSIGN PINS
led = Pin(3, Pin.OUT)
hw = Pin(8, Pin.IN, Pin.PULL_DOWN)
my_pin = hw.value()

led.off()
# MAKE THINGS HAPPEN
while True:
  my_pin = hw.value()

  while my_pin==hw.value(): #  if the pin is high do this
    # do stuff
    if my_pin > 0:
        led.on()  # No need for else
        print("Motion detected!")
        sleep(2) # So I can see what's going on until it works correctly
    else:
        led.off()  # HOW ELSE IS THE LIGHT GOING TO TURN OFF?
        print("Scanning...")
        sleep(2)

    break

[karfas]

while True:
  my_pin = hw.value()
  while my_pin==hw.value(): #  if the pin is high do this
    break

This is a creative (but strange) way to use while...break. You are using while as replacement for an if.

Also note that while my_pin==hw.value(): will not work as stated in the comment..
The code inside the while will run when the input does not change in respect to the value read in the while True loop.
This is different to "if the pin is high" !

In my opinion, you can reduce all this to

while True:
    my_pin = hw.value()
    if my_pin > 0:
        led.on()  # No need for else
        print("Motion detected!")
        sleep(2) # So I can see what's going on until it works correctly
    else:
        led.off()  # HOW ELSE IS THE LIGHT GOING TO TURN OFF?
        print("Scanning...")
        sleep(2)

[marinehm]

This makes more sense than my code. It does work and the code is "clean". Now to figure out why I have to touch the sensor for it to notice "motion".

[bixb922]

I don't see the definition of "high".
I suppose you want to check for a value of 1 on pin 8. The variable hw has the pin object, not the pin value. You are comparing the pin object with 1 or 0, that will always be false. The pin value is hw.value()

In case of doubt, use print to get what is happening.

[davefes]

For a ESP32:

hw = Pin(32, Pin.IN, Pin.PULL_DOWN)
my_pin = hw.value()

print (my_pin)
and it should read 0 because it is pulled-down and I expected that the code would not run.

When you take pin8 hi then it should read 1 and
the rest of the code should run

Which works for me.

[davefes]

Sorry, I have been working on a ESP32 and pin 8 is not allowed:
https://github.com/peterhinch/micropython-samples/tree/master/ESP32
see the .pdf

Are there pins on your device that one shouldn't use?

[marinehm]

In the REPL: if I type:
print(hw())
I get the value of the hw Pin . How do I ask if it's either high or low?
When I import Pin and then help(Pin), I see that "high" and "low" are valid arguments.

[robert-hh]

high() and low() are valid methods (function calls), not names for returned values. a call to hw() or hw.value() returns 0 or 1, depending on the input level. 0 maps to a low level, 1 to a high level.

[bixb922]

hw.value()==1 to test if on, hw.value()==0 to test if off.

[marinehm]

Something strange just happened. I was pulling off the sensor to hook it back up to my ESP8266 and run the Arduino sketch on it. The LED came on without the sensor connected. Playing around with this some more. The jumper wire still connected to the Pico HW Pin. It acts as a capacitance touch sensor. Senses my finger at close to 2 inches from the wire and the LED comes on. No Sensor! This will work for me with turning on the light for my shed. BUT, I wanted the motion detector for my hall and bathroom light. For now, I will use the esp8266/Arduino.IDE until I investigate this phenomenon some more.

[peterhinch]

CMOS inputs are very high impedance. This behaviour is well known, but it can't really be relied on. There are also hazards with static discharge. Touching an open circuit input can damage the device if your body becomes electrically charged.

[marinehm]

I need some work with Micropython.
Here's my completed Arduino sketch:

/*
  Microwave Motion Sensor
  LOLIN (WEMOS) Mini-D Pro
  HW-MS03 Microwave motion sensor
  1000uf 25V Capacitor
  Lolin Relay
  MQTT to publish "Motion detected!" so I can log it from my MQTT Server

//  Capacitor across the  +  - was removed from the final product, will re-evaluate
//  when the relay is cycled on/off a few times.

  Senses motion from front and back of the PCB.  Not so much from the sides.
  This even worked through a fairly thick plastic table that I used as a barrier.

  By Nick Sebring; 2-4-2023
*/

// INSTALL WIFI, MQTT
#include <ESP8266WiFi.h>
#include <PubSubClient.h>

// Connect to the WiFi
const char* ssid = "MYSSID";
const char* password = "MYPASSWORD";
const char* mqtt_server = "192.168.1.13";

WiFiClient espClient;
PubSubClient client(espClient);

boolean reconnect() {  // **********************************************************
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print (F("Contacting MQTT server..."));
    // Attempt to connect
    { if (client.connect("MCSHED"))    //assign a "client name".  Each wemos must have a unique name
        Serial.println (F("connected"));

      return client.connected();

      Serial.print (F("Failed to connect. "));
      Serial.println (F(" Attempting connection again in 3 seconds"));
      // Wait 3 seconds before retrying
      //      delay(3000);
      return 0;
    }
  }
}

void setup()
{
  {
    Serial.begin(9600);
    client.setServer(mqtt_server, 1883);
  }
  // Connect to WiFinetwork
  Serial.println();
  Serial.println();
  Serial.print (F("Connecting to "));
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  WiFi.mode(WIFI_STA);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    //Serial.begin(9600);
    Serial.print (F("."));
  }
  Serial.println (F(""));
  Serial.println (F("WiFi connected"));
  // Print the IP address
  Serial.print (F("Local IP: "));
  Serial.println(WiFi.localIP());

  //  *********************************************************************************

  Serial.println(F("Microwave sensor located in the Motorcycle shed"));


}
void loop()
{
  if (!client.connected()) {
    reconnect();
  }
  
  {
    int HWPin = 16;
    int Relay = 14;
    int val;                          // This is the value from the HW-MS03 Microwave motion sensor

    pinMode(HWPin, INPUT);          // HW-MS03 Microwave motion sensor
    pinMode(BUILTIN_LED, OUTPUT);   // BLUE LED onboard as OUTPUT (High/LOW is inverted)
    pinMode(Relay, OUTPUT);
    val = digitalRead(HWPin);

    if (val == HIGH)  //low = no motion, high = motion
    { Serial.println("Motion detected.  ");
      digitalWrite(BUILTIN_LED, LOW);
      digitalWrite(Relay, HIGH);  //Turn something on
      client.publish("Outside/MC_shed", "Motion detected!");
      delay(450000); //   5000= 5 sec   300000= 5min, 600000= 10 min
      //  Keep it on for a period of time  //
    }

    else
    {
      Serial.println("Scanning...");
      digitalWrite(BUILTIN_LED, HIGH);
      digitalWrite(Relay, LOW);  //Turn something off
    }
  }
}