UV Sensor ML8511

[epierre]

@mrc-core said:

ML8511

Have you checked the wiring (from https://github.com/sparkfun/ML8511_Breakout/blob/master/firmware/MP8511_Read_Example/MP8511_Read_Example.ino):

Connect the following MP8511 breakout board to Arduino:
3.3V = 3.3V
OUT = A0
GND = GND
EN = 3.3V
3.3V = A1

[mrc-core]

Looking over the pin connection that you have post i do see one mistake i have done.
I did not connect de 3.3V to A1 pin.

I'm gona trie it when i'm at home.

The sensor is connected to domoticz but the readings are very low... 0.2 UVI

[mrc-core]

I have done some changings to the code and corrected de 3.3V = A1 Pin that i did not had in the first code.
Onde day has passed with the changes and the result off this days is what you can see on the image below:

I dont now if this results are correct. I'm going to let the sensor outiside until the end of the week and see the results.
Does anyone in the forum have a UV sensor working? Is this chart correct ??

[AWI]

@mrc-core looks like you are using Domoticz.. Look for the Weather Underground virtual hardware.

You can have WU report most of the weather related data from a station nearby. This includes UV measurement in a similar graph you have.

Or my opinion : It looks like a correct graph to me but will depend on your local sun intensity.

[epierre]

a quick question as I try to revive a node with UV sensor (a UVM-30A) : is there a simple way to simulate the UV after sundown which is the time I can test it ?

[AWI]

@epierre UV led? :bowtie:

[mrc-core]

Ok i have now configured the Weather Underground virtual hardware let's see what will happen during the day off tomorrow.
For what i can seen the UV sensor is detecting the UV normally between 11h and 17h....
I'm going to make one new change on the code to introduce the reading s of the MP8511 voltage.

And i'm going to change the location off the prototype in my house.

To test the UV sensor at night you can use a UV light.

[epierre]

@mrc-core said:

To test the UV sensor at night you can use a UV light.

does a halogen lamp does this ?

[AWI]

@epierre The spectrum of UV is between 10 en 400 nanometer. so in relation to the spectrum of UV:

and an excerpt from medical study:

"Halogen lamps emit significant levels of ultraviolet radiation and should be doped or covered with glass prior to use"

But in summary: not much

[mrc-core]

This is my new code for this sensor and reajusted to library 2.1.1

/**
 * The MySensors Arduino library handles the wireless radio link and protocol
 * between your home built sensors/actuators and HA controller of choice.
 * The sensors forms a self healing radio network with optional repeaters. Each
 * repeater and gateway builds a routing tables in EEPROM which keeps track of the
 * network topology allowing messages to be routed to nodes.
 *
 * Created by Henrik Ekblad <henrik.ekblad@mysensors.org>
 * Copyright (C) 2013-2015 Sensnology AB
 * Full contributor list: https://github.com/mysensors/Arduino/graphs/contributors
 *
 * Documentation: http://www.mysensors.org
 * Support Forum: http://forum.mysensors.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 *******************************
 *
 * REVISION HISTORY
 * Version 1.0 - epierre
 * Contribution: bulldoglowell, gizmocuz
 *
 * DESCRIPTION
 * Connect sensor ML8511 / Arduino:
 *
 *  3.3V = 3.3V
 *  OUT = A0
 *  GND = GND
 *  EN = 3.3V
 *  Arduino 3.3V = Arduino A1
 *
 * License: Attribution-NonCommercial-ShareAlike 3.0 Unported (CC BY-NC-SA 3.0)
 */

// Enable debug prints
#define MY_DEBUG

// Enable and select radio type attached 
#define MY_RADIO_NRF24
//#define MY_RADIO_RFM69
//#define MY_RS485

#include <SPI.h>
#include <MySensors.h>  
#include <SPI.h>

//Hardware pin definitions
int REF_3V3 = A1;
int UVOUT = A0;

#define CHILD_ID_UV 0

unsigned long SLEEP_TIME = 30*1000; // Sleep time between reads (in milliseconds)

MyMessage uvMsg(CHILD_ID_UV, V_UV);

float lastUV = -1;
unsigned long lastSend =0; 

void presentation()
{
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo("UV Sensor", "3.0");

  // Register all sensors to gateway (they will be created as child devices)
  present(CHILD_ID_UV, S_UV, "ML8511_UV");
}

void setup()  
{ 
  //gw.begin(NULL, 9, true);
  pinMode(UVOUT, INPUT);
  pinMode(REF_3V3, INPUT);
}

void loop()      
{
  int uvLevel = averageAnalogRead(UVOUT);
  int refLevel = averageAnalogRead(REF_3V3);
  unsigned long currentTime = millis();

  //Use the 3.3V power pin as a reference to get a very accurate output value from sensor
  float outputVoltage = 3.3 / refLevel * uvLevel;
 
  //float outputVoltage = 5.0 * uvLevel/1024;
  float uvIntensity = mapfloat(outputVoltage, 0.99, 2.8, 0.0, 15.0);          //Convert the voltage to a UV intensity level

  Serial.print("output: ");
  Serial.print(refLevel);

  Serial.print("ML8511 output: ");
  Serial.print(uvLevel);

  Serial.print(" / ML8511 voltage: ");
  Serial.print(outputVoltage);

  Serial.print(" / UV Intensity (mW/cm^2): ");
  Serial.print(uvIntensity);

  Serial.println();

  if ((uvIntensity != lastUV)||(currentTime-lastSend >= 5*60*1000)) 
  {
      lastSend=currentTime;
      send(uvMsg.set(uvIntensity,2));
      lastUV = uvIntensity;
  }
  delay(100);
}
 
//Takes an average of readings on a given pin
//Returns the average
int averageAnalogRead(int pinToRead)
{
  byte numberOfReadings = 8;
  unsigned int runningValue = 0; 

  for(int x = 0 ; x < numberOfReadings ; x++)
    runningValue += analogRead(pinToRead);
  runningValue /= numberOfReadings;

  return(runningValue);  
}

//The Arduino Map function but for floats
//From: http://forum.arduino.cc/index.php?topic=3922.0
float mapfloat(float x, float in_min, float in_max, float out_min, float out_max)
{
  return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
}```

[BeniK]

@mrc-core Thanks for the code. The code works fine but I am seing the node reporting direct measurements to the gateway every single second, spamming the gateway.

Is there anything I can do to stop this behavior and transmit averages; in example - every minute or every 5 minutes?

Thanks in advance!

[alexsh1]

@benik change

 delay(100);

to

delay(300000); //5 mins reporting