pixl.js with analog moister sensor

[espruino-discuss]

Posted at 2018-05-29 by furuskog

Hello!
I have a analog moister sensor, how do I make it work? How can I read the proper values from pin A0. I have a CR2032 battery. And i think the sensor can run on 3,3V

function onTimer() {
  // Get the soil moister as a string
  var h = analogRead(A0);
  
  // Clear display
  g.clear();
  // Use the small font for a title
  g.setFontBitmap();
  g.drawString("Soil moister:");
  // Use a large font for the value itself
  g.setFontVector(30);
  g.drawString(h, (g.getWidth()-g.stringWidth(h))/2,10);
  // Update the screen
  g.flip();
}

// Update soil moister every 2 seconds
setInterval(onTimer,2000);
// Update soil moister immediately
onTimer();

---

Attachments:

• Bild 2018-05-29 kl. 22.08.jpg
  
• Bild 2018-05-29 kl. 22.10.jpg

[gfwilliams]

Posted at 2018-05-30 by @gfwilliams

Hi! I think your wiring might be a bit off - the power wires seem to be connected to 3.3v and RST. See: http://www.espruino.com/Pixl.js#pinout

Basically you want to move the blue wire 3 pins downwards to connect it to GND, and that will probably help a lot.

[espruino-discuss]

Posted at 2018-05-30 by furuskog

Diffrent numbers but thet change i sequence. Thanks for the sudgestion

Attachments:

• 7FBFB674-9DC2-4B62-8DB9-98577A2CA547.jpeg

[espruino-discuss]

Posted at 2018-05-31 by furuskog

I think IM doing something wrong any ideas? Does anyone here have an idea how to extract data from it? Is it even analog? The 3 wires att sig, vcc and gnd.

[gfwilliams]

Posted at 2018-05-31 by @gfwilliams

I don't really know - do you get an obvious digital output out of it if you stick it in water?

[espruino-discuss]

Posted at 2018-05-31 by J{a}SON

i have something similar from a grooove sensor kit. i can try it this weekend, or at least give the arduino code. i know i just did an analog read off of a0. the values ranged from 0 - 800 or so. using it for plant soil moisture, i had values between 300 and 650 as acceptable moisture.

[espruino-discuss]

Posted at 2018-05-31 by furuskog

Thank you Im looking forward to your findings or your code :)

[espruino-discuss]

Posted at 2018-05-31 by furuskog

No it just cycles between some values not dependant on the environment

[espruino-discuss]

Posted at 2018-06-01 by @yerpj

There is big chances the moisture sensor is analog, like the one from Adafruit (https://www.sparkfun.com/products/13322).

Then, the code is quite easy:
Just use the analogRead(PIN) function with the correct pin name and there it is. Then you can add some threshold or whatever you want depending on your application

[espruino-discuss]

Posted at 2018-06-01 by furuskog

Thank you, so My code above should do the trick?

[espruino-discuss]

Posted at 2018-06-01 by @yerpj

It should. If not, could you please share the sensor model? (reference, name, manufacturer or datasheet)

[espruino-discuss]

Posted at 2018-06-01 by J{a}SON

here's the arduino code i'll try to convert to a pixl when i get home this weekend. it reads from a moisture sensor, and a temperature/humidity sensor, and displays the values to an rgb display. unfortunately i won't be able to change the display color based on the moisture level, but it will be a good test. in my case i'm using an arduino shield with a grove sensor kit, so it will be a good test on the pixl as a shield as well.

#include "Arduino.h"
#include "Wire.h" 
#include <rgb_lcd.h>
#include <TH02_dev.h>
#include <stdio.h>
#include <math.h>
#include <TimeLib.h>
#include <TimeAlarms.h>

rgb_lcd lcd;

const int button = 2;       // connect a button
const int buzzer = 3;       // connect a buzzer
// Test code for Grove - Moisture Sensor 
int sensorPin = A0; // select the input pin for the potentiometer
int moisture = -1; // variable to store the value coming from the sensor7
int prec = 0;
int buttonPress = 0;
int displayOn = 1;

void setup() {
    Serial.begin(9600);
    // declare the ledPin as an OUTPUT:
    pinMode(button, INPUT); //set button as an INPUT device
    pinMode(buzzer, OUTPUT);   //set LED as an OUTPUT device
    // set up the LCD's number of columns and rows:
    lcd.begin(16, 2);
    // Set the LCD background color
    setColor();
    Serial.println("****TH02_dev demo by seeed studio****\n");
    /* Power up,delay 150ms,until voltage is stable */
    delay(150);
    /* Reset HP20x_dev */
    TH02.begin();
    delay(100);
    
    /* Determine TH02_dev is available or not */
    Serial.println("TH02_dev is available.\n");   

    Alarm.timerRepeat(5, readSensors);
    Alarm.timerRepeat(60, displayOff);
}

void loop() {
    buttonPress = digitalRead(button); //read the status of the button
    if( buttonPress && !displayOn ) {
      lcd.display();
      displayOn = 1;
      setColor();
    }
    //digitalWrite(buzzer, btn);

    Alarm.delay(10);
}

void readSensors() {
  Serial.println("Reading sensors");
  // read the value from the sensor:
  moisture = analogRead(sensorPin);
  Serial.print("Moisture = " );
  Serial.println(moisture);
  float temper = TH02.ReadTemperature(); 
  Serial.println("Temperature: ");   
  Serial.print(temper);
  Serial.println("C\r\n");

  float humidity = TH02.ReadHumidity();
  Serial.println("Humidity: ");
  Serial.print(humidity);
  Serial.println("%\r\n");
  char message1[16];
  char message2[16];
  float ftemp = 1.8*temper + 32;
  long t = lround(ftemp);
  int tm = int((ftemp-floor(ftemp))*100)%100;
  long h = lround(humidity);
  int hm = int((humidity-floor(humidity))*100)%100;
  long m = moisture;
  sprintf(message1, "%ld.%dF, %ld.%dRH", t, tm, h, hm);
  Serial.println(int((temper-floor(temper))*100)%100);
  setColor();
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print(message1);
  lcd.setCursor(0,1);
  sprintf(message2, "Moisture: %3ld", m);
  lcd.print(message2);
}

void displayOff() {
  if( buttonPress ) {
    buttonPress = 0;
  }
  else {
    lcd.noDisplay();
    lcd.setColorAll();
    displayOn = 0;
  }
}

void setColor() {
  if( displayOn ) {
    if( moisture < 0 ) {
      lcd.setColorAll();
    }
    else if( moisture < 300 ) {
      lcd.setColor(RED);
    }
    else if( moisture < 650 ) {
      lcd.setColor(GREEN);
    }
    else {
      lcd.setColor(BLUE); 
    }
  }
}

[espruino-discuss]

Posted at 2018-06-01 by @yerpj

I suspect that the kind of sensor that J{a}SON is using is this one: http://wiki.seeedstudio.com/Grove-Temperature_and_Humidity_Sensor_Pro/
If true, It is probably discussing through I2C, which cannot be the case of the sensor of @furuskog, which has only 3 pins (I2C would have at least 4 pins)

[espruino-discuss]

Posted at 2018-06-01 by J{a}SON

the moisture sensor is only using 3 of the pins: vcc, gnd, sig. it's this one
http://wiki.seeedstudio.com/Grove-Moisture_Sensor/

[espruino-discuss]

Posted at 2018-06-01 by @yerpj

Well in this case @furuskog probably owns some kind of clone of this moisture sensor, it should work fine with a simple analogRead(PIN). If not working, possible issues could be

1. the sensor is not correctly wired up
2. the PIN is not the one which is connected to the sensor
3. the soil humidity is way too low and the sensor is continuously reading the minimal value
4. the transistor on the moisture sensor is dead

[espruino-discuss]

Posted at 2018-06-01 by J{a}SON

i'm going to convert my shield arduino code to pixl anyway, just as an exercise. it was accurate on the arduino as a setup for my indoor plant starters, but it didn't have a sleep mode, and drained the batteries too quickly. i look forward to seeing how energy efficient the pixl can be with this setup.

[espruino-discuss]

Posted at 2018-06-01 by furuskog

yes I have done that it cycles through.

[espruino-discuss]

Posted at 2018-06-01 by @yerpj

Are you powering the sensor with 3.3 or 5.0 V?

[espruino-discuss]

Posted at 2018-06-02 by furuskog

hmm 3.3v seems to work now.

in water
h = 0.45629882812
h = 0.45678710937
h = 0.45971679687
h = 0.46044921875
h = 0.46020507812
h = 0.4619140625
h = 0.4619140625
h = 0.462890625
h = 0.46362304687

in air
h = 0.00024414062
h = 0.00048828125
h = 0.0009765625
h = -0.00024414062
h = 0.00024414062

Now i just have to calculate it in %, an have som treshold for 0% because of the fluxuation, maybe an upper limit too?

I will check the code you guys provided :)

[espruino-discuss]

Posted at 2018-06-02 by furuskog

I came up with this

var high = 0.55;
var low = 0.0017;

function map_value(val, in_min, in_max, out_min, out_max){
  var result = (val - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
  
  if(result < out_min) {
    return out_min;  
  } 
  else if(result > out_max) {
    return out_max;
  }
  
  return result;
}

function onTimer() {
  var h = analogRead(A0);
  var hp = map_value(h, low, high, 0, 100);
  var percentage = hp.toFixed(0)+"%";
  
  // Clear display
  g.clear();
  // Use the small font for a title
  g.setFontBitmap();
  g.drawString("Soil moister:");
  // Use a large font for the value itself
  g.setFontVector(10);
  g.drawString(percentage, 5,10);
  // Update the screen
  g.flip();
}

// Update soil moister every 2 seconds
setInterval(onTimer, 2000);
// Update soil moister immediately
onTimer();

Feedback on the code is welcome

I have 3 pucks im gooing to try next :) Im gooing to send via bluetooth to my pixl.js

edit:
Strange the high and low changes with battery vs plug

[espruino-discuss]

Posted at 2018-06-02 by @yerpj

Strange the high and low changes with battery vs plug

Yes that's is probably the downside of this sensor. Due to its circuit, the sensor output may be a function of VCC. You could try to power it through an LDO (low dropout regulator).

Or you can also monitor its voltage through a resistor divider an compensate digitally ?

Anyway, good to know that you finally got it work!

[espruino-discuss]

Posted at 2018-06-02 by furuskog

I c. I just changed the ”high” variable to a lower value and it worked. Thanks for the help! :)

[espruino-discuss]

Posted at 2018-06-02 by J{a}SON

i just tested my seeed grove moisture sensor with success, and a few notes:

1. need to convert from the sensor document values (0 - 950) to the espruino analogRead range (0-1)
2. different values depending on battery power vs usb. not sure how much the values will change over the life of the battery. sensor in water from the battery was .47, and from usb was .55
3. in order to use the sensor from the grove shield, i had to put a jumper from the 3.3v to 5v pins, as the shield uses the 5v pin for power. the sensor works with 3.3v - 5v range, so this was acceptable

when i replace my full code i'll post in another thread

[espruino-discuss]

Posted at 2018-06-02 by furuskog

Good news!

Even got it work on a esp32 with espruino
Here is the code

var high = 0.5;
var low = 0.0;

function map_value(val, in_min, in_max, out_min, out_max){
  var result = (val - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
  
  if(result < out_min) {
    return out_min;  
  } 
  else if(result > out_max) {
    return out_max;
  }
  
  return result;
}

function onTimer() {
  var h = analogRead(D35); // D35 is a adc-port (analog to digital converter)
  var hp = map_value(h, low, high, 0, 100);
  var percentage = hp.toFixed(0)+"%";
  
  console.log("Soil moister", percentage);
}

// Update soil moister every 2 seconds
setInterval(onTimer, 2000);
// Update soil moister immediately
onTimer();

To bad there are no bluetooth support yet :(

[espruino-discuss]

Posted at 2018-06-02 by Wilberforce

Ahh - but there is now Bluetooth support for the esp32!

[espruino-discuss]

Posted at 2018-06-02 by furuskog

Nice! I just asumed because of the documentation sudgested otherwise :)

[gfwilliams]

Posted at 2018-06-04 by @gfwilliams

It's still pretty beta, but with a bit of work you can get it doing simple advertising stuff :)

[espruino-discuss]

Posted at 2018-06-06 by furuskog

Nice

[espruino-discuss]

Posted at 2018-06-09 by furuskog

Im trying to broadcast ble data with the esp32. But its not implemented yet the console informs me. Didnt you guys say it worked now?

var high = 0.5;
var low = 0.0;

function map_value(val, in_min, in_max, out_min, out_max){
  var result = (val - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
  
  if(result < out_min) {
    return out_min;  
  } 
  else if(result > out_max) {
    return out_max;
  }
  
  return result;
}

function onTimer() {
  var h = analogRead(D35);
  var hp = map_value(h, low, high, 0, 100);
  var percentage = hp.toFixed(0)+"%";
  
  NRF.setServices({
    0xBCDE : {
      0xABCD : {
        value : percentage,
        readable : true
      }
    }
  });
  console.log("Soil moister", percentage);
}

// Update soil moister every 2 seconds
setInterval(onTimer, 2000);
// Update soil moister immediately
onTimer();

Console

Soil moister 0%
WARNING: has connected not implemented yet

[gfwilliams]

Posted at 2018-06-11 by @gfwilliams

I think I said it was very beta. You can get advertising going with some work - maybe with NRF.wake()? It'll still give you warnings all over the place.

If you have issues with it post on the ESP32 forum though. ESP32 isn't something I can provide any support for.

[espruino-discuss]

Posted at 2018-06-11 by furuskog

Ok, thanks I will try that.