Does anyone know about the issue, when I enter a 3-digit number after '0x' there is an error during verification, and when I only enter a 2-digit number, it can be verified correctly, but since this is for calibrating an NPK sensor, the numbers will be all over the place, is there a solution?
I moved your topic to an appropriate forum category @kyroo_kay72.
In the future, when creating a topic please take some time to pick the forum category that best suits the subject of your topic. There is an "About the _____ category" topic at the top of each category that explains its purpose.
This is an important part of responsible forum usage, as explained in the "How to get the best out of this forum" guide. The guide contains a lot of other useful information. Please read it.
Thanks in advance for your cooperation.
#include "WiFi.h"
#include "ThingSpeak.h"
#define RE 4
#define RXD2 17
#define TXD2 16
WiFiClient client;
unsigned long myChannelNumber = 1;
const char * myWriteAPIKey = "Put in your API key here";
const byte humi[] = {0x01, 0x03, 0x00, 0x00, 0x00, 0x01, 0xe84, 0x0a};
const byte temp[] = {0x01, 0x03, 0x00, 0x01, 0x00, 0x01, 0xd5, 0xca};
const byte cond[] = {0x01, 0x03, 0x00, 0x02, 0x00, 0x01, 0x25, 0xca};
const byte phph[] = {0x01, 0x03, 0x00, 0x03, 0x00, 0x01, 0x74, 0x0a};
const byte nitro[] = {0x01, 0x03, 0x00, 0x04, 0x00, 0x01, 0xec5, 0xcb};
const byte phos[] = {0x01, 0x03, 0x00, 0x05, 0x00, 0x01, 0xe94, 0x0b};
const byte pota[] = {0x01, 0x03, 0x00, 0x06, 0x00, 0x01, 0xe64, 0x0b};
const byte sali[] = {0x01, 0x03, 0x00, 0x07, 0x00, 0x01, 0xe35, 0xcb};
const byte tds[] = {0x01, 0x03, 0x00, 0x08, 0x00, 0x01, 0xe05, 0xc8};
byte values[11];
// ThingSpeak information.
#define NUM_FIELDS 8
#define HUMIDITY_FIELD 1
#define TEMPERATURE_FIELD 2
#define CONDUCTIVITY_FIELD 3
#define pH_FIELD 4
#define NITROGEN_FIELD 5
#define PHOSPHORUS_FIELD 6
#define POTASSIUM_FIELD 7
#define RSSI_FIELD 8
const char* ssid = "????????"; // your network SSID (name)
const char* password = "????????"; // your network password
void setup() {
Serial.begin(4800);
Serial1.begin(4800, SERIAL_8N1, RXD2, TXD2);
WiFi.mode(WIFI_STA);
ThingSpeak.begin(client); // Initialize ThingSpeak
pinMode(RE, OUTPUT);
// digitalWrite(RE, LOW);
//delay(3000);
digitalWrite(RE, LOW);
delay(1000);
WiFi.mode(WIFI_STA);
delay(3000);
}
void loop() {
// Connect or reconnect to WiFi
if(WiFi.status() != WL_CONNECTED){
Serial.print("Attempting to connect");
while(WiFi.status() != WL_CONNECTED){
WiFi.begin(ssid, password);
delay(5000);
}
Serial.println("\nConnected.");
}
float val1, val2, val3, val4, val5, val6, val7, val8, val9;
//********************* HUMIDITY *************************
Serial.print("Humidity: ");
digitalWrite(RE, HIGH);
delay(10);
for (uint8_t i = 0; i < sizeof(humi); i++ ) Serial1.write( humi[i] );
Serial1.flush();
digitalWrite(RE, LOW);
delay(100);
for (byte i = 0; i < 7; i++) {
values[i] = Serial1.read();
}
val1 = int(values[3]<<8|values[4]);
val1 = val1/10;
Serial.print(" = ");
Serial.print(val1,1);
Serial.println(" %");
delay(200);
//********************* TEMPERATURE *************************
Serial.print("Temperature: ");
digitalWrite(RE, HIGH);
delay(10);
for (uint8_t i = 0; i < sizeof(temp); i++ ) Serial1.write( temp[i] );
Serial1.flush();
digitalWrite(RE, LOW);
delay(100);
for (byte i = 0; i < 7; i++) {
values[i] = Serial1.read();
}
val2 = int(values[3]<<8|values[4]);
val2=val2/10;
Serial.print(" = ");
Serial.print(val2,1);
Serial.println(" deg.C");
delay(200);
//********************* CONDUCTIVITY *************************
Serial.print("Conductivity: ");
digitalWrite(RE, HIGH);
delay(10);
for (uint8_t i = 0; i < sizeof(cond); i++ ) Serial1.write( cond[i] );
Serial1.flush();
digitalWrite(RE, LOW);
delay(100);
for (byte i = 0; i < 7; i++) {
values[i] = Serial1.read();
}
val3 = int(values[3]<<8|values[4]);
Serial.print(" = ");
Serial.print(val3);
Serial.println(" uS/cm");
delay(200);
//********************* Ph *************************
Serial.print("pH: ");
digitalWrite(RE, HIGH);
delay(10);
for (uint8_t i = 0; i < sizeof(phph); i++ ) Serial1.write( phph[i] );
Serial1.flush();
digitalWrite(RE, LOW);
delay(100);
for (byte i = 0; i < 7; i++) {
values[i] = Serial1.read();
// Serial.print(values[i], HEX);
// Serial.print(' ');
}
val4 = int(values[3]<<8|values[4]);
val4 = val4/10;
Serial.print(" = ");
Serial.println(val4,1);
delay(200);
//********************* NITROGEN *************************
Serial.print("Nitrogen: ");
digitalWrite(RE, HIGH);
delay(10);
for (uint8_t i = 0; i < sizeof(nitro); i++ ) Serial1.write( nitro[i] );
Serial1.flush();
digitalWrite(RE, LOW);
delay(100);
for (byte i = 0; i < 7; i++) {
values[i] = Serial1.read();
// Serial.print(values[i], HEX);
// Serial.print(' ');
}
val5 = int(values[3]<<8|values[4]);
Serial.print(" = ");
Serial.print(val5);
Serial.println(" mg/L");
delay(200);
//********************* PHOSPHORUS *************************
Serial.print("Phosphorus: ");
digitalWrite(RE, HIGH);
delay(10);
for (uint8_t i = 0; i < sizeof(phos); i++ ) Serial1.write( phos[i] );
Serial1.flush();
digitalWrite(RE, LOW);
delay(100);
for (byte i = 0; i < 7; i++) {
values[i] = Serial1.read();
// Serial.print(values[i], HEX);
// Serial.print(' ');
}
val6 = int(values[3]<<8|values[4]);
Serial.print(" = ");
Serial.print(val6);
Serial.println(" mg/L");
delay(200);
//********************* POTASSIUM *************************
Serial.print("Potassium: ");
digitalWrite(RE, HIGH);
delay(10);
for (uint8_t i = 0; i < sizeof(pota); i++ ) Serial1.write( pota[i] );
Serial1.flush();
digitalWrite(RE, LOW);
delay(100);
for (byte i = 0; i < 7; i++) {
values[i] = Serial1.read();
}
val7 = int(values[3]<<8|values[4]);
Serial.print(" = ");
Serial.print(val7);
Serial.println(" mg/L");
delay(200);
//********************* SALINITY *************************
Serial.print("Salinity: ");
digitalWrite(RE, HIGH);
delay(10);
for (uint8_t i = 0; i < sizeof(sali); i++ ) Serial1.write( sali[i] );
Serial1.flush();
digitalWrite(RE, LOW);
delay(100);
for (byte i = 0; i < 7; i++) {
values[i] = Serial1.read();
// Serial.print(values[i], HEX);
// Serial.print(' ');
}
val8 = int(values[3]<<8|values[4]);
Serial.print(" = ");
Serial.print(val8);
Serial.println(" g/L");
delay(200);
//********************* TDS *************************
Serial.print("TDS: ");
digitalWrite(RE, HIGH);
delay(10);
for (uint8_t i = 0; i < sizeof(tds); i++ ) Serial1.write( tds[i] );
Serial1.flush();
digitalWrite(RE, LOW);
delay(100);
for (byte i = 0; i < 7; i++) {
values[i] = Serial1.read();
// Serial.print(values[i], HEX);
// Serial.print(' ');
}
val9 = int(values[3]<<8|values[4]);
Serial.print(" = ");
Serial.print(val9);
Serial.println(" mg/L");
delay(200);
Serial.println(WiFi.RSSI());
Serial.println("");
Serial.println("");
Serial.println("");
delay(1000);
// set the fields with the values
ThingSpeak.setField(1, val1);
ThingSpeak.setField(2, val2);
ThingSpeak.setField(3, val3);
ThingSpeak.setField(4, val4);
ThingSpeak.setField(5, val5);
ThingSpeak.setField(6, val6);
ThingSpeak.setField(7, val7);
ThingSpeak.setField(8, (WiFi.RSSI()));
int x = ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
if(x == 200){
Serial.println("Channel update successful.");
}
else{
Serial.println("Problem updating channel. HTTP error code " +
String(x));
}
delay(600000);
}
// send data every 10 minutes
The datatype of the arrays is byte.
A byte can only be between 0x00 and 0xFF.
Why do you think that the calibration values need to have 3 hexadecimal digits?
How is the calibration done?
i got the codes from :
7 in 1 Soil Monitor : 6 Steps - Instructables
0xc5 would be correct, just remove e from all of those.
Also, you might find better sources for information from this forum. Try to make search here with soil 7 in 1
From the Soil Sensor Manual:
The last two bytes are a Cyclic Redundancy Check of the first 6 bytes, with the least significant byte first.
There is a an online CRC calculator at:
CRC - 01 03 00 00 00 01
The result is shown as 0x0A84.
The least significant byte is sent first, so the last two bytes become 0x84 0x0A.
Thus we get:
const byte humi[] = {0x01, 0x03, 0x00, 0x00, 0x00, 0x01, 0x84, 0x0a};
I've filled in the data for you for the other ones in the following links:
CRC - 01 03 00 01 00 01
CRC - 01 03 00 02 00 01
CRC - 01 03 00 03 00 01
CRC - 01 03 00 04 00 01
CRC - 01 03 00 05 00 01
CRC - 01 03 00 06 00 01
CRC - 01 03 00 07 00 01
CRC - 01 03 00 08 00 01
Edit: Removed errors in links.
1 Like
The 7 1 sensors are a scam; there is no such thing as an NPK sensor for a hobbyist. The pros have them, but they are very expensive.
Thank you very much, you are very helpful
Yes, you are correct.
There are simple parameters like temperature, conductivity, pH that can be measured successfully, but elements like Potassium, Nitrogen and Phosphorous aren't in that category.
Nitrogen is inert in itself and is usually measured as nitrite, nitrate or ammonia.
There are colorimetric tests for phosphorous. There might be a specific ion electrode for Potassium, but the usual method is flame photometry or atomic absorption spectroscopy.
I used to do all these tests, but all were lab based. You could get sondes with collections of sensors for water analysis, but very expensive, maintenance and calibration intensive.
It all depends on description how is it sold..
Description of one honest supplier:
"NPK storage.The normal use method is that you measure NPK by other methods and then write the data to the device through RS485 command.
It cannot be measured actually, because the nitrogen, phosphorus and potassium values measured by the equipment are not used as a reference. It is ok if it is only for project acceptance."
In fact, NPK registers of these devices are all writeable
If it's like the sensor in the image, which looks like a row of metal electrodes, then it's very unlikely to be able to measure NPK.
How could it.
The point was that honest seller tells that.
"you measure NPK by other methods and then write the data to the device through RS485 command."
What's the purpose of this functionality remains mystery to me...
1 Like