Sensor for Trash cans

fehe

Hi,

we are trying the sensor from milesight EM400-MUD and EM400-TLD

We are trying to measure the if a trash can is full or empty.

we then want to visulize this in grafana. se attached picture.

however we have some issue with our formula in nodered. that is calculating the function "distance" to values between 1 and 0. ( this so we can make a graph in grafana.

the problems:

Both of the sensor is showing the same value in grafana. (this should be due to the wrong forumula in nodered)
It is hard for us to put a value when the trash bin is empty. Due to the plastic bag moving around.
sometimes we get a value from the sensor saying "max" witch need to be filtret out. (it is the value 65533)
any other improvments in the formula in nodered?

Nodered funktion:

// (500 - 48) / (500 - 48)   == Empty  == 1
// (500 - 1200) / (500 - 48)  == FULL == 0
// 650 == TOM
// 48 == FULL


let newmsg = {}
newmsg.payload = (650 - msg.payload.value) / (650 - 50)


return newmsg;

fehe

I manged to solve my issues. here is the code.

// Constants
const MAX_VALID_DISTANCE = 650;  // Adjusted based on your sensor's max distance
const MIN_VALID_DISTANCE = 50;   // Adjusted based on your sensor's min distance
const MAX_SENSOR_VALUE = 65533;  // Max value that needs to be filtered out

// Initialize new message
let newmsg = {};

// Check for max sensor value and filter it out
if (msg.payload.value === MAX_SENSOR_VALUE) {
    // Ignore this reading
    return null;
}

// Calculate the clamped distance
const clampedValue = Math.max(MIN_VALID_DISTANCE, Math.min(MAX_VALID_DISTANCE, msg.payload.value));

// Calculate the normalized value (0 to 1)
newmsg.payload = (MAX_VALID_DISTANCE - clampedValue) / (MAX_VALID_DISTANCE - MIN_VALID_DISTANCE);

// Return the new message
return newmsg;

Jesper

fehe Nice! Some math needed and then translating that to code.