💬 Soil Moisture Sensor
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@ul7aajr said in 💬 Soil Moisture Sensor:
Try to never try resistive sensors. It is reaaly wrong way. I try to bult few resistive. No way.
I try to buld some inductive. Yes, it's possible, but lot of analog parts, difficult to calibrate. No way too.
Capacitive senors is most reliable and has a simple digital schematics.Good luck you on your way)
PS: here is my own sensor http://vegimatics.com/products/current/
want do discuss - wellcome)I'm currently building a sensor that uses the Chirp devices. I want to chain them together. You can get them for 4 dollars each.
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@ul7aajr said in 💬 Soil Moisture Sensor:
Try to never try resistive sensors. It is reaaly wrong way. I try to bult few resistive. No way.
I try to buld some inductive. Yes, it's possible, but lot of analog parts, difficult to calibrate. No way too.
Capacitive senors is most reliable and has a simple digital schematics.Good luck you on your way)
PS: here is my own sensor http://vegimatics.com/products/current/
want do discuss - wellcome)I'm currently building a sensor that uses the Chirp devices. I want to chain them together. You can get them for 4 dollars each.
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@neverdie They support I2C. So in theory you can connect a whole bunch to a pin. I'm trying to figure out if I can detect all of them and then automatically give each a unique ID.
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@dbemowsk Changing the Chirp's I2C address is very easy actually.
#include <I2CSoilMoistureSensor.h> #include <Wire.h> I2CSoilMoistureSensor sensor(0x20); // connect the reset pin (5) of the Chirp to a pin on your Arduino. It will create a small reset signal. This tells the chirp it should not be a stand-alone ensor, but an I2C connected one. If it receives I1C data shortyl after a reset (few seconds), then it will understand. int resetPin = 4; void setup() { pinMode(resetPin, OUTPUT); delay(1000); digitalWrite(resetPin, HIGH); // sets the digital pin 13 on delay(100); // waits for a second digitalWrite(resetPin, LOW); // sets the digital pin 13 off delay(1000); Wire.begin(); Serial.begin(9600); sensor.begin(); // reset sensor delay(1000); // give some time to boot up Serial.print("I2C Soil Moisture Sensor Address: "); Serial.println(sensor.getAddress(),HEX); Serial.print("Sensor Firmware version: "); Serial.println(sensor.getVersion(),HEX); Serial.println(); Serial.print("Change address to 0x21 ..."); if (sensor.setAddress(0x21,true)) // set Sensor Address to 0x21 and reset Serial.println("... DONE"); else Serial.println("... ERROR"); Serial.println(); } /*loop scans I2C bus and displays foud addresses*/ void loop() { byte error, address; int nDevices; Serial.println("Scanning..."); nDevices = 0; for(address = 1; address < 127; address++ ) { // The i2c_scanner uses the return value of // the Write.endTransmisstion to see if // a device did acknowledge to the address. Wire.beginTransmission(address); error = Wire.endTransmission(); if (error == 0) { Serial.print("I2C device found at address 0x"); if (address<16) Serial.print("0"); Serial.print(address,HEX); Serial.println(" !"); nDevices++; } else if (error==4) { Serial.print("Unknow error at address 0x"); if (address<16) Serial.print("0"); Serial.println(address,HEX); } } if (nDevices == 0) Serial.println("No I2C devices found\n"); else Serial.println("done\n"); delay(3000); // wait 5 seconds for next scan }The default address is 0x20. So my idea is to just keep scanning, and if I find a 0x20 Chirp, then I change its I2C address to 0x21 and higher. Repeat as necessary until all 0x20 devices are gone.
The only thing I'm not sure about is if this is possible. If I can pick them off one by one this way.
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@dbemowsk Changing the Chirp's I2C address is very easy actually.
#include <I2CSoilMoistureSensor.h> #include <Wire.h> I2CSoilMoistureSensor sensor(0x20); // connect the reset pin (5) of the Chirp to a pin on your Arduino. It will create a small reset signal. This tells the chirp it should not be a stand-alone ensor, but an I2C connected one. If it receives I1C data shortyl after a reset (few seconds), then it will understand. int resetPin = 4; void setup() { pinMode(resetPin, OUTPUT); delay(1000); digitalWrite(resetPin, HIGH); // sets the digital pin 13 on delay(100); // waits for a second digitalWrite(resetPin, LOW); // sets the digital pin 13 off delay(1000); Wire.begin(); Serial.begin(9600); sensor.begin(); // reset sensor delay(1000); // give some time to boot up Serial.print("I2C Soil Moisture Sensor Address: "); Serial.println(sensor.getAddress(),HEX); Serial.print("Sensor Firmware version: "); Serial.println(sensor.getVersion(),HEX); Serial.println(); Serial.print("Change address to 0x21 ..."); if (sensor.setAddress(0x21,true)) // set Sensor Address to 0x21 and reset Serial.println("... DONE"); else Serial.println("... ERROR"); Serial.println(); } /*loop scans I2C bus and displays foud addresses*/ void loop() { byte error, address; int nDevices; Serial.println("Scanning..."); nDevices = 0; for(address = 1; address < 127; address++ ) { // The i2c_scanner uses the return value of // the Write.endTransmisstion to see if // a device did acknowledge to the address. Wire.beginTransmission(address); error = Wire.endTransmission(); if (error == 0) { Serial.print("I2C device found at address 0x"); if (address<16) Serial.print("0"); Serial.print(address,HEX); Serial.println(" !"); nDevices++; } else if (error==4) { Serial.print("Unknow error at address 0x"); if (address<16) Serial.print("0"); Serial.println(address,HEX); } } if (nDevices == 0) Serial.println("No I2C devices found\n"); else Serial.println("done\n"); delay(3000); // wait 5 seconds for next scan }The default address is 0x20. So my idea is to just keep scanning, and if I find a 0x20 Chirp, then I change its I2C address to 0x21 and higher. Repeat as necessary until all 0x20 devices are gone.
The only thing I'm not sure about is if this is possible. If I can pick them off one by one this way.
@alowhum That is nice. Some I2C devices have it hard coded and do not allow this from my understanding.
Vera Plus running UI7 with MySensors, Sonoffs and 1-Wire devices
Visit my website for more Bits, Bytes and Ramblings from me: http://dan.bemowski.info/ -
@alowhum That is nice. Some I2C devices have it hard coded and do not allow this from my understanding.
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@dbemowsk True. But it's another reason why I think the Chirp devices are pretty great soil sensors.
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@ul7aajr said in 💬 Soil Moisture Sensor:
Try to never try resistive sensors. It is reaaly wrong way. I try to bult few resistive. No way.
I try to buld some inductive. Yes, it's possible, but lot of analog parts, difficult to calibrate. No way too.
Capacitive senors is most reliable and has a simple digital schematics.Good luck you on your way)
PS: here is my own sensor http://vegimatics.com/products/current/
want do discuss - wellcome)I'm currently building a sensor that uses the Chirp devices. I want to chain them together. You can get them for 4 dollars each.
@alowhum
Not sure I2C is a good idea excepting case all sensors inside one room. It can be used just for testing to make it easy. As usual RS485 used to connect any sensors to nework. And there is Modbus protocol over RS485 that enable to use not only custom sensors, but kind of devices can be usefull in automatic systems. For example pump controllers, valve controllers....So.. no good perspecrives to go
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Well, the Chirp doesn't support that protocol, so..
It does have a mini arduino inside. Perhaps you could reprogram it. Then I will happily have a look ;-) -
I found another, simpler sensor on Aliexpress.
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My two cents. A soil moisture sensor that requires no extra hardware (not counting electric wire). Highly inspired by everything I've read in this thread. Comments welcome.
Excuse the long post./* Name: MYS_MoistureSensor.ino Created: 5/25/2017 1:04:35 PM Author: Rob Soil moisture measuring by using stainless steel rods (or any other conductor). Probably the simplest project ever, since only a MySensors-node and some wire is needed to set things up. The sketch alternates current during measuring to prevent corrosion of the rods due to electrolyses. Odd readings may occur when starting (eg. increasing soil moisture for no apparent reason), please just allow the electrodes to settle down in the soil. No extra hardware needed. I use an Arduino Mini 3V3, powered on two AA cells. It is suggested you set the fuses for a lower Brown Out Detection (BOD). But anything goes. Just tie D4 and A0 together to one rod, and D5 and A1 to another rod. This is sensor one. For the second sensor tie D6 and A2 together to one rod, and D7 and A3 to another rod. Connect a pushbutton between GND and D3 if you need a button that makes the node report immediately (can be omitted) Measurement are taken every minute and send to the gateway if different from the previous reading. In case of no changes, the node reports itself every four hours. The output is between 0 (dry) and 100 (wet). Can also be used as a depth moisture sensor with three sensor zones; in that case use one (common) long rod and three smaller sensors along the height of the rod and configure the sketch accordingly. sensors[0] = { 4, A0, 5, A1, -1, false }; sensors[1] = { 4, A0, 6, A2, -1, false }; sensors[2] = { 4, A0, 7, A3, -1, false }; */ #include "Header.h" // Enable debug Serial.prints to serial monitor //#define MY_DEBUG #if defined MY_DEBUG #define Sprintln(a) (Serial.println(a)) #define Sprint(a) (Serial.print(a)) #else #define Sprintln(a) #define Sprint(a) #endif // Enable and select radio type attached #define MY_RADIO_RFM69 #define MY_RFM69_FREQUENCY RF69_868MHZ #define MY_IS_RFM69HW // Use PA_LOW for RF24+PA (Power Amplifier) //#define MY_RF24_PA_LEVEL RF24_PA_LOW //#define MY_RF24_PA_LEVEL RF24_PA_MAX #define MY_NODE_ID 4 #include <MySensors.h> #define ACK 0 // = false #define CHILD_ID 1 #define REPORTNOWSWITCH_PIN 3 // Arduino Digital I/O pin for button/reed switch (must be an interrupt pin!) #define NUM_MOISTURE_SENSORS 2 #define CHILD_ID_TEMPERATURE (CHILD_ID+NUM_MOISTURE_SENSORS+1) #define SENSOR1_ROD1_DIGITAL 4 #define SENSOR1_ROD1_ANALOG A0 #define SENSOR1_ROD2_DIGITAL 5 #define SENSOR1_ROD2_ANALOG A1 #define SENSOR2_ROD1_DIGITAL 6 #define SENSOR2_ROD1_ANALOG A2 #define SENSOR2_ROD2_DIGITAL 7 #define SENSOR2_ROD2_ANALOG A3 #define SLEEP_IN_MS 60000 // every minute a new measurement #define EVERY_15_MINUTES (3600000/4/SLEEP_IN_MS) #define EVERY_4_HOURS (3600000*4/SLEEP_IN_MS) #define NUM_READS (int)10 // Number of sensor reads for filtering int countLoops; int8_t interruptedBy = -1; int oldBatLevel; float oldTemperature; int output_value; /// Included in Header.h: //typedef struct { // int digital_input_a; // int analog_input_a; // int digital_input_b; // int analog_input_b; // int level; // bool connected; //} sensorWiring; sensorWiring sensors[NUM_MOISTURE_SENSORS]; MyMessage msgMoistureSensor(CHILD_ID, V_LEVEL); MyMessage msgChipTemp(CHILD_ID_TEMPERATURE, V_TEMP); void before() { // All buttons as input-pullup as per ATMEGA recommendation to use less power (and more safety) // (http://electronics.stackexchange.com/questions/43460/how-should-unused-i-o-pins-be-configured-on-atmega328p-for-lowest-power-consumpt) for (int i = 1; i <= 8; i++) { pinMode(i, INPUT_PULLUP); } // Now explicity set pins as needed // Setup report-now switch, activate internal pull-up pinMode(REPORTNOWSWITCH_PIN, INPUT_PULLUP); // Initialize sensor variables // Connect Digital pin 4 to Analog input A0 and a metal rod // Connect Digital pin 5 to Analog input A1 and another metal rod. sensors[0] = { SENSOR1_ROD1_DIGITAL, SENSOR1_ROD1_ANALOG, SENSOR1_ROD2_DIGITAL, SENSOR1_ROD2_ANALOG, -1, false }; // Connect Digital pin 6 to Analog input A2 and a metal rod // Connect Digital pin 7 to Analog input A3 and another metal rod. sensors[1] = { SENSOR2_ROD1_DIGITAL, SENSOR2_ROD1_ANALOG, SENSOR2_ROD2_DIGITAL, SENSOR2_ROD2_ANALOG, -1, false }; for (int i = 0; i<NUM_MOISTURE_SENSORS; i++) sensors[i].connected = testSensorConnections(sensors[i]); } void setup() { } void presentation() { sendSketchInfo("Moisture Sensor", "1.1", ACK); for (int i = 0; i < NUM_MOISTURE_SENSORS; i++) { if (sensors[i].connected) present(CHILD_ID+i, S_MOISTURE, ACK); } present(CHILD_ID_TEMPERATURE, S_TEMP); } void loop() { bool reportNow = (interruptedBy == digitalPinToInterrupt(REPORTNOWSWITCH_PIN)); if (reportNow) { // Little trick for debouncing the switch attachInterrupt(digitalPinToInterrupt(REPORTNOWSWITCH_PIN), debounce, RISING); wait(500); Sprintln(F("Report now switch pressed")); countLoops = 0; } for (int i = 0; i < NUM_MOISTURE_SENSORS; i++) { if (sensors[i].connected) { output_value = measure(sensors[i]); if ((sensors[i].level != output_value) || reportNow) { sensors[i].level = output_value; send(msgMoistureSensor.setSensor(CHILD_ID+i).set(output_value), ACK); } } } // Every fifteen minutes; poll temperature if (countLoops%EVERY_15_MINUTES==0 || reportNow) { float newTemp = readTemp(); if (oldTemperature != newTemp || reportNow) { send(msgChipTemp.set(newTemp, 1), ACK); oldTemperature = newTemp; } int batLevel = getBatteryLevel(); if ((oldBatLevel != batLevel) || reportNow) // ...but only when changed, or when button is pressed; { sendBatteryLevel(batLevel, ACK); oldBatLevel = batLevel; } } // So you know I'm alive if (countLoops == EVERY_4_HOURS) { sendHeartbeat(ACK); countLoops = 0; } countLoops++; interruptedBy = sleep(digitalPinToInterrupt(REPORTNOWSWITCH_PIN), FALLING, SLEEP_IN_MS); } // Connect Digital pin 'digital_input_a' to Analog input 'analog_input_a' and a metal rod, // do the same for b long measure(sensorWiring sensor) { long total = 0; int reading_a = 0; int reading_b = 0; for (int i = 0; i<NUM_READS; i++) { // Left to right reading_a = measureOneDirection(sensor.digital_input_a, sensor.digital_input_b, sensor.analog_input_a); // Right to left reading_b = measureOneDirection(sensor.digital_input_b, sensor.digital_input_a, sensor.analog_input_b); total += reading_a + reading_b; } return map(total / (2 * NUM_READS), 1023, 0, 0, 100); } long measureOneDirection(int digital_input_1, int digital_input_2, int analog_input_1) { pinMode(digital_input_2, OUTPUT); digitalWrite(digital_input_2, LOW); pinMode(digital_input_1, INPUT_PULLUP); delayMicroseconds(100); long reading = analogRead(analog_input_1); //delayMicroseconds(25); pinMode(digital_input_1, INPUT); // High impedance pinMode(digital_input_2, INPUT); // High impedance delay(1); Sprint(F("measureOneDirection - Reading ")); Sprintln(reading); return reading; } // test the connections of both rods of a sensor boolean testSensorConnections(sensorWiring moistureSensor) { return (testSensorConnection(moistureSensor.digital_input_a, moistureSensor.analog_input_a) && testSensorConnection(moistureSensor.digital_input_b, moistureSensor.analog_input_b)); } // test if digital pin is connected to correct analog pin boolean testSensorConnection(int digital_input, int analog_input) { pinMode(digital_input, OUTPUT); digitalWrite(digital_input, HIGH); delayMicroseconds(100); long reading_1 = analogRead(analog_input); digitalWrite(digital_input, LOW); delayMicroseconds(100); long reading_2 = analogRead(analog_input); pinMode(digital_input, INPUT); // High impedance delay(1); Sprint(F("testSensorConnection - Reading1 ")); Sprintln(reading_1); Sprint(F("testSensorConnection - Reading2 ")); Sprintln(reading_2); bool correct = ((reading_1 == 1023) && (reading_2 == 0)); return correct; } float readTemp() { #if defined (xxMY_RADIO_RFM69) && !defined(MY_RFM69_NEW_DRIVER) return _radio.readTemperature(-3); #else // Read 1.1V reference against MUX3 return (readMUX(_BV(REFS1) | _BV(REFS0) | _BV(MUX3)) - 125) * 0.1075f; #endif } long readMUX(uint8_t aControl) { long result; ADMUX = aControl; delay(20); // Wait for Vref to settle noInterrupts(); // start the conversion ADCSRA |= _BV(ADSC) | _BV(ADIE); set_sleep_mode(SLEEP_MODE_ADC); // sleep during sample interrupts(); sleep_mode(); // reading should be done, but better make sure // maybe the timer interrupt fired while (bit_is_set(ADCSRA, ADSC)); // Reading register "ADCW" takes care of how to read ADCL and ADCH. result = ADCW; return result; } // Battery measure int getBatteryLevel() { int results = (readVcc() - 2000) / 10; if (results > 100) results = 100; if (results < 0) results = 0; return results; } // end of getBandgap // when ADC completed, take an interrupt EMPTY_INTERRUPT(ADC_vect); long readVcc() { long result; // Read 1.1V reference against AVcc result = readMUX(_BV(REFS0) | _BV(MUX3) | _BV(MUX2) | _BV(MUX1)); result = 1126400L / result; // Back-calculate AVcc in mV (1024 steps times 1100 mV (1.1V) = 1126400L) return result; } // Utter nonsense, but needed for attaching an interrupt to... void debounce() { }Your code will fail compiling in Arduino 1.8.5 (mysensors 2.2.0) with the following errors:
/mnt/data/Dropbox/UTV/Arduino/SoilMoisture/SoilMoisture.ino: In function 'void before()': /mnt/data/Dropbox/UTV/Arduino/SoilMoisture/SoilMoisture.ino:112:114: warning: extended initializer lists only available with -std=c++11 or -std=gnu++11 sensors[0] = { SENSOR1_ROD1_DIGITAL, SENSOR1_ROD1_ANALOG, SENSOR1_ROD2_DIGITAL, SENSOR1_ROD2_ANALOG, -1, false }; ^ /mnt/data/Dropbox/UTV/Arduino/SoilMoisture/SoilMoisture.ino:112:14: warning: extended initializer lists only available with -std=c++11 or -std=gnu++11 sensors[0] = { SENSOR1_ROD1_DIGITAL, SENSOR1_ROD1_ANALOG, SENSOR1_ROD2_DIGITAL, SENSOR1_ROD2_ANALOG, -1, false }; ^ /mnt/data/Dropbox/UTV/Arduino/SoilMoisture/SoilMoisture.ino:116:114: warning: extended initializer lists only available with -std=c++11 or -std=gnu++11 sensors[1] = { SENSOR2_ROD1_DIGITAL, SENSOR2_ROD1_ANALOG, SENSOR2_ROD2_DIGITAL, SENSOR2_ROD2_ANALOG, -1, false }; ^ /mnt/data/Dropbox/UTV/Arduino/SoilMoisture/SoilMoisture.ino:116:14: warning: extended initializer lists only available with -std=c++11 or -std=gnu++11 sensors[1] = { SENSOR2_ROD1_DIGITAL, SENSOR2_ROD1_ANALOG, SENSOR2_ROD2_DIGITAL, SENSOR2_ROD2_ANALOG, -1, false }; ^So the following code need tobe changed to something valid
sensors[0] = { SENSOR1_ROD1_DIGITAL, SENSOR1_ROD1_ANALOG, SENSOR1_ROD2_DIGITAL, SENSOR1_ROD2_ANALOG, -1, false }; sensors[1] = { SENSOR2_ROD1_DIGITAL, SENSOR2_ROD1_ANALOG, SENSOR2_ROD2_DIGITAL, SENSOR2_ROD2_ANALOG, -1, false };I'm not a c++ guy so I can't tell what needs to be done. Maybe you or someone else would like to help out?
Cheers!
EDIT: After removing the file platform.txt for solving another problem (as suggested here) The problem above vanished. So strange. But it works now so... :sunglasses: :sunglasses: :sunglasses:
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I've found that measuring soil moisture by the electrical resistance is not a trivial task.
If the probe is put into compact soil containing no mold, you'll typically get a high reading even at very low moisture levels. It will most likely always stay within the span of 90-100%.
However if the probe is put into pure mold, the readings will range between 0% to 100%.
My conclusion is that measuring directly in the soil is very unpredictable. A better solution might be to surround the probe with some material that adapts the ambient humidity from whatever kind of soil it's put into.
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Perhaps the capacitive sensors are more useful.
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@mfalkvidd It depends from mineral composition of soil. I buld capacitive sensor with additional electrodes to measure salinity of soil with resistive method (it measures the resistance of soil to alternating current). So, while value of capacitive sensor stable and let say 50%, value of resistive can be critically changed by adding few milliliters of water with fertilizer. Capacitive value will be chaged only to 60% e.g.
It's not a good idea to use resistive sensor, especcialy measuring resistance to direct current.
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@mfalkvidd It depends from mineral composition of soil. I buld capacitive sensor with additional electrodes to measure salinity of soil with resistive method (it measures the resistance of soil to alternating current). So, while value of capacitive sensor stable and let say 50%, value of resistive can be critically changed by adding few milliliters of water with fertilizer. Capacitive value will be chaged only to 60% e.g.
It's not a good idea to use resistive sensor, especcialy measuring resistance to direct current.
