Hello, thanks for the quick reply.
I see. At the moment I'm only sending a simple 'a' instead of the command itself from the pi.
This is the .cpp that comes with the DFRobot code
/*
* file DFRobot_PH.cpp * @ https://github.com/DFRobot/DFRobot_PH
*
* Arduino library for Gravity: Analog pH Sensor / Meter Kit V2, SKU: SEN0161-V2
*
* Copyright [DFRobot](http://www.dfrobot.com), 2018
* Copyright GNU Lesser General Public License
*
* version V1.0
* date 2018-04
*/
#if ARDUINO >= 100
#include "Arduino.h"
#else
#include "WProgram.h"
#endif
#include "DFRobot_PH.h"
#include <EEPROM.h>
#define EEPROM_write(address, p) {int i = 0; byte *pp = (byte*)&(p);for(; i < sizeof(p); i++) EEPROM.write(address+i, pp[i]);}
#define EEPROM_read(address, p) {int i = 0; byte *pp = (byte*)&(p);for(; i < sizeof(p); i++) pp[i]=EEPROM.read(address+i);}
#define PHVALUEADDR 0x00 //the start address of the pH calibration parameters stored in the EEPROM
DFRobot_PH::DFRobot_PH()
{
this->_temperature = 25.0;
this->_phValue = 7.0;
this->_acidVoltage = 2032.44; //buffer solution 4.0 at 25C
this->_neutralVoltage = 1500.0; //buffer solution 7.0 at 25C
this->_voltage = 1500.0;
}
DFRobot_PH::~DFRobot_PH()
{
}
void DFRobot_PH::begin()
{
EEPROM_read(PHVALUEADDR, this->_neutralVoltage); //load the neutral (pH = 7.0)voltage of the pH board from the EEPROM
Serial.print("_neutralVoltage:");
Serial.println(this->_neutralVoltage);
if(EEPROM.read(PHVALUEADDR)==0xFF && EEPROM.read(PHVALUEADDR+1)==0xFF && EEPROM.read(PHVALUEADDR+2)==0xFF && EEPROM.read(PHVALUEADDR+3)==0xFF){
this->_neutralVoltage = 1500.0; // new EEPROM, write typical voltage
EEPROM_write(PHVALUEADDR, this->_neutralVoltage);
}
EEPROM_read(PHVALUEADDR+4, this->_acidVoltage);//load the acid (pH = 4.0) voltage of the pH board from the EEPROM
Serial.print("_acidVoltage:");
Serial.println(this->_acidVoltage);
if(EEPROM.read(PHVALUEADDR+4)==0xFF && EEPROM.read(PHVALUEADDR+5)==0xFF && EEPROM.read(PHVALUEADDR+6)==0xFF && EEPROM.read(PHVALUEADDR+7)==0xFF){
this->_acidVoltage = 2032.44; // new EEPROM, write typical voltage
EEPROM_write(PHVALUEADDR+4, this->_acidVoltage);
}
}
float DFRobot_PH::readPH(float voltage, float temperature)
{
float slope = (7.0-4.0)/((this->_neutralVoltage-1500.0)/3.0 - (this->_acidVoltage-1500.0)/3.0); // two point: (_neutralVoltage,7.0),(_acidVoltage,4.0)
float intercept = 7.0 - slope*(this->_neutralVoltage-1500.0)/3.0;
//Serial.print("slope:");
//Serial.print(slope);
//Serial.print(",intercept:");
//Serial.println(intercept);
this->_phValue = slope*(voltage-1500.0)/3.0+intercept; //y = k*x + b
return _phValue;
}
void DFRobot_PH::calibration(float voltage, float temperature,char* cmd)
{
this->_voltage = voltage;
this->_temperature = temperature;
strupr(cmd);
phCalibration(cmdParse(cmd)); // if received Serial CMD from the serial monitor, enter into the calibration mode
}
void DFRobot_PH::calibration(float voltage, float temperature)
{
this->_voltage = voltage;
this->_temperature = temperature;
if(cmdSerialDataAvailable() > 0){
phCalibration(cmdParse()); // if received Serial CMD from the serial monitor, enter into the calibration mode
}
}
boolean DFRobot_PH::cmdSerialDataAvailable()
{
char cmdReceivedChar;
static unsigned long cmdReceivedTimeOut = millis();
while(Serial.available()>0){
if(millis() - cmdReceivedTimeOut > 500U){
this->_cmdReceivedBufferIndex = 0;
memset(this->_cmdReceivedBuffer,0,(ReceivedBufferLength));
}
cmdReceivedTimeOut = millis();
cmdReceivedChar = Serial.read();
if (cmdReceivedChar == '\n' || this->_cmdReceivedBufferIndex==ReceivedBufferLength-1){
this->_cmdReceivedBufferIndex = 0;
strupr(this->_cmdReceivedBuffer);
return true;
}else{
this->_cmdReceivedBuffer[this->_cmdReceivedBufferIndex] = cmdReceivedChar;
this->_cmdReceivedBufferIndex++;
}
}
return false;
}
byte DFRobot_PH::cmdParse(const char* cmd)
{
byte modeIndex = 0;
if(strstr(cmd, "ENTERPH") != NULL){
modeIndex = 1;
}else if(strstr(cmd, "EXITPH") != NULL){
modeIndex = 3;
}else if(strstr(cmd, "CALPH") != NULL){
modeIndex = 2;
}
return modeIndex;
}
byte DFRobot_PH::cmdParse()
{
byte modeIndex = 0;
if(strstr(this->_cmdReceivedBuffer, "ENTERPH") != NULL){
modeIndex = 1;
}else if(strstr(this->_cmdReceivedBuffer, "EXITPH") != NULL){
modeIndex = 3;
}else if(strstr(this->_cmdReceivedBuffer, "CALPH") != NULL){
modeIndex = 2;
}
return modeIndex;
}
void DFRobot_PH::phCalibration(byte mode)
{
char *receivedBufferPtr;
static boolean phCalibrationFinish = 0;
static boolean enterCalibrationFlag = 0;
switch(mode){
case 0:
if(enterCalibrationFlag){
Serial.println(F(">>>Command Error<<<"));
}
break;
case 1:
enterCalibrationFlag = 1;
phCalibrationFinish = 0;
Serial.println();
Serial.println(F(">>>Enter PH Calibration Mode<<<"));
Serial.println(F(">>>Please put the probe into the 4.0 or 7.0 standard buffer solution<<<"));
Serial.println();
break;
case 2:
if(enterCalibrationFlag){
if((this->_voltage>1322)&&(this->_voltage<1678)){ // buffer solution:7.0{
Serial.println();
Serial.print(F(">>>Buffer Solution:7.0"));
this->_neutralVoltage = this->_voltage;
Serial.println(F(",Send EXITPH to Save and Exit<<<"));
Serial.println();
phCalibrationFinish = 1;
}else if((this->_voltage>1854)&&(this->_voltage<2210)){ //buffer solution:4.0
Serial.println();
Serial.print(F(">>>Buffer Solution:4.0"));
this->_acidVoltage = this->_voltage;
Serial.println(F(",Send EXITPH to Save and Exit<<<"));
Serial.println();
phCalibrationFinish = 1;
}else{
Serial.println();
Serial.print(F(">>>Buffer Solution Error Try Again<<<"));
Serial.println(); // not buffer solution or faulty operation
phCalibrationFinish = 0;
}
}
break;
case 3:
if(enterCalibrationFlag){
Serial.println();
if(phCalibrationFinish){
if((this->_voltage>1322)&&(this->_voltage<1678)){
EEPROM_write(PHVALUEADDR, this->_neutralVoltage);
}else if((this->_voltage>1854)&&(this->_voltage<2210)){
EEPROM_write(PHVALUEADDR+4, this->_acidVoltage);
}
Serial.print(F(">>>Calibration Successful"));
}else{
Serial.print(F(">>>Calibration Failed"));
}
Serial.println(F(",Exit PH Calibration Mode<<<"));
Serial.println();
phCalibrationFinish = 0;
enterCalibrationFlag = 0;
}
break;
}
}
And this is the library that also comes with the code jus in case you also need it.
/*
* file DFRobot_PH.h * @ https://github.com/DFRobot/DFRobot_PH
*
* Arduino library for Gravity: Analog pH Sensor / Meter Kit V2, SKU: SEN0161-V2
*
* Copyright [DFRobot](http://www.dfrobot.com), 2018
* Copyright GNU Lesser General Public License
*
* version V1.0
* date 2018-04
*/
#ifndef _DFROBOT_PH_H_
#define _DFROBOT_PH_H_
#if ARDUINO >= 100
#include "Arduino.h"
#else
#include "WProgram.h"
#endif
#define ReceivedBufferLength 10 //length of the Serial CMD buffer
class DFRobot_PH
{
public:
DFRobot_PH();
~DFRobot_PH();
void calibration(float voltage, float temperature,char* cmd); //calibration by Serial CMD
void calibration(float voltage, float temperature);
float readPH(float voltage, float temperature); // voltage to pH value, with temperature compensation
void begin(); //initialization
private:
float _phValue;
float _acidVoltage;
float _neutralVoltage;
float _voltage;
float _temperature;
char _cmdReceivedBuffer[ReceivedBufferLength]; //store the Serial CMD
byte _cmdReceivedBufferIndex;
private:
boolean cmdSerialDataAvailable();
void phCalibration(byte mode); // calibration process, wirte key parameters to EEPROM
byte cmdParse(const char* cmd);
byte cmdParse();
};
#endif