Soil Sensor analog values differ on Uno vs Pro Mini

[Moshe Livne]

@fred97 , i also use domoticz. If you read this thread form the start, you will see that the arduino converts the moisture reading to something in the range 0-1023 (or 682 if you use mini pro). 1023 is 0 moisture, 0 is 100% moisture. so, moisture content is (1023 - reading)/1023*100.

Hope this answers your question!

Moshe

[fred97]

thanks you ,

i have try your sketch but don't work send only O

send: 2-2-0-0 s=0,c=1,t=1,pt=2,l=2,st=ok:0
444
send: 2-2-0-0 s=0,c=1,t=1,pt=2,l=2,st=ok:0
470
send: 2-2-0-0 s=0,c=1,t=1,pt=2,l=2,st=ok:0
1023
send: 2-2-0-0 s=0,c=1,t=1,pt=2,l=2,st=ok:0

i think the problem is inside converter in percentage ....

240 when is in water and 1023 when completly dry .

[Moshe Livne]

@fred97 did you change anything in the calculation? the values in the println seems correct. do not remove the static casts - they are essential.

[BulldogLowell]

@Moshe-Livne said:

Serial.println(soilValue);
gw.send(msg.set(static_cast<int>(static_cast<float>(1023 - soilValue))/1023*100))

how about just using the map() function...

Serial.println(soilValue);
gw.send(msg.set(map(soilValue, 0, 1023, 0 ,100));

[Moshe Livne]

@BulldogLowell would have used it if I knew it existed.... would it work is reverse? (1023,0, 0, 100)?

[BulldogLowell]

@Moshe-Livne

Try it!!

int soilValue = 250;

void setup() 
{
  Serial.begin(115200);
  Serial.println(map(soilValue, 1023,0,100,0));
}

void loop() 
{
  
}

have you run into 123dcircuits yet?

[Moshe Livne]

@BulldogLowell not yet!!! my first encounter with arduino was only a few weeks ago.... so much to learn! the wood are lovely dark and deep, but i have promises to keep....

[fred97]

hello

it's working but is not inverted :+1:

314
send: 2-2-0-0 s=0,c=1,t=1,pt=4,l=4,st=ok:30
294
send: 2-2-0-0 s=0,c=1,t=1,pt=4,l=4,st=ok:28
287
send: 2-2-0-0 s=0,c=1,t=1,pt=4,l=4,st=ok:28
299
send: 2-2-0-0 s=0,c=1,t=1,pt=4,l=4,st=ok:29
313
send: 2-2-0-0 s=0,c=1,t=1,pt=4,l=4,st=ok:30
1023
send: 2-2-0-0 s=0,c=1,t=1,pt=4,l=4,st=ok:100

100 is when is dry and 220/250 is when the sensor is in water .
i just need little more help for invert value , 100 = in water and 0 when is dry

thx

[BulldogLowell]

@fred97

@BulldogLowell said:

gw.send(msg.set(map(soilValue, 0, 1023, 0 ,100));

like this:

gw.send(msg.set(map(soilValue, 100, 250, 0, 100));

it maps 100 to zero and 250 to 100

Let me know if that works for you.

or... you can try this to bound the returned value by zero and 100:

gw.send((max(min(map(soilValue, 100,250,0,100), 100), 0)));

confusing but is is mapping the value, and limiting to 100 and then making sure it is at least zero (i.e. non-negative).

or just:

gw.send(constrain(map(soilValue, 100,250,0,100), 0, 100));

[fred97]

gw.send(msg.set(map(soilValue, 100, 250, 0, 100)));```

you have forget one ) at last .

sensor started, id 2
send: 2-2-0-0 s=255,c=0,t=17,pt=0,l=5,st=ok:1.4.1
send: 2-2-0-0 s=255,c=3,t=6,pt=1,l=1,st=ok:0
read: 0-0-2 s=255,c=3,t=6,pt=0,l=1:M
send: 2-2-0-0 s=255,c=3,t=11,pt=0,l=25,st=ok:Soil Moisture Sensor - an
send: 2-2-0-0 s=255,c=3,t=12,pt=0,l=3,st=ok:1.0
send: 2-2-0-0 s=0,c=0,t=7,pt=0,l=5,st=ok:1.4.1
1023
send: 2-2-0-0 s=0,c=1,t=1,pt=4,l=4,st=ok:615
285
send: 2-2-0-0 s=0,c=1,t=1,pt=4,l=4,st=ok:123

250 is when is in water and 1023 is dry , it's alway inverted , i can test 2 other exemple because there is a problem in sketch maybe ;or ) when is try this

gw.send((max(min(map(soilValue, 100,250,0,100), 100), 0)));

and for other 2 exemple i can send to arduino compiling error

sketch_may24a.ino: In function 'void loop()':
sketch_may24a:31: error: no matching function for call to 'MySensor::send(long int)'
C:\Program Files (x86)\Arduino\libraries\MySensors/MySensor.h:142: note: candidates are: bool MySensor::send(MyMessage&, bool)

[BulldogLowell]

@fred97

Post your entire sketch.

[fred97]

#include <SPI.h>
#include <MySensor.h>

#define ANALOG_INPUT_SOIL_SENSOR A0
#define CHILD_ID 0 // Id of the sensor child

MySensor gw;
MyMessage msg(CHILD_ID, V_HUM);
int lastSoilValue = -1;

void setup()
{
gw.begin();

// Send the sketch version information to the gateway and Controller
gw.sendSketchInfo("Soil Moisture Sensor - analog", "1.0");
// sets the soil sensor analog pin as input
pinMode(ANALOG_INPUT_SOIL_SENSOR, INPUT);
// Register all sensors to gw (they will be created as child devices)
gw.present(CHILD_ID, S_HUM);
}

void loop()
{
// Read analog soil value
int soilValue = analogRead(ANALOG_INPUT_SOIL_SENSOR);

if (soilValue != lastSoilValue) {
Serial.println(soilValue);
gw.send(msg.set(map(soilValue, 100, 250, 0, 100)));
lastSoilValue = soilValue;
}
// Power down the radio and arduino until analog input changes.
gw.sleep(1000);
}

is the same sketch but i have changed only

gw.send(msg.set(static_cast<int>(static_cast<float>(1023 - soilValue))/1023*100)); // Send the relative moisture. this will probably work only on nano or uno as I used 1023

by this

gw.send(msg.set(map(soilValue, 100, 250, 0, 100)));

i don't understand why is alway inverted ??

[BulldogLowell]

@fred97 said:

i don't understand why is alway inverted ??

try to use this:

gw.send(msg.set(constrain(map(soilValue, 1023, 250, 0, 100),0,100)));

it maps 1023 to zero and 250 to 100... that is what you want, yes?

#include <SPI.h>
#include <MySensor.h>

#define ANALOG_INPUT_SOIL_SENSOR A0
#define CHILD_ID 0 // Id of the sensor child

MySensor gw;
MyMessage msg(CHILD_ID, V_HUM);
int lastSoilValue = -1;

void setup()
{
  gw.begin();

  // Send the sketch version information to the gateway and Controller
  gw.sendSketchInfo("Soil Moisture Sensor - analog", "1.0");
  // sets the soil sensor analog pin as input
  pinMode(ANALOG_INPUT_SOIL_SENSOR, INPUT);
  // Register all sensors to gw (they will be created as child devices)
  gw.present(CHILD_ID, S_HUM);
}

void loop()
{
  // Read analog soil value
  int soilValue = analogRead(ANALOG_INPUT_SOIL_SENSOR);

  if (soilValue != lastSoilValue) {
    Serial.println(soilValue);
    gw.send(msg.set(constrain(map(soilValue, 1023, 250, 0, 100),0,100)));
    lastSoilValue = soilValue;
  }
  // Power down the radio and arduino until analog input changes.
  gw.sleep(1000);
}

[fred97]

thanks you very much work great !