[Jim Moore]

Hi
I have built a low cost EC sensor using the Atlas Scientific probe. The EZO board for the pH sensor has the same interface so if you look on my recent blog I give all the details you should need. I assume you want to deploy this with battery power and solar recharge so the Mayfly will sleep most of the time. Setup code is included in my blog and you will want this initially to set up the Atlas EZO interface board which provides serial comm to the Mayfly.

Hope this helps

[Jim Moore]

Drew-
I can’t offer any specific suggestions for your problems but I recognize some of the code that I used for a similar project to gather Electrical Conductivity (EC) data. I have attached my writeup on this project which includes my code. I have several of these stations deployed and some for almost a year and have not experienced any of the problems that you have had. The only issues I had is with J1:

[Jim Moore]

I noticed that Atlas Scientific sensors are not in the ModularSensors list. I have built two EC sensor stations that are currently deployed in Great Marsh primarily to monitor stormwater runoff from the Pa Tpk. Scott Ensign has suggested I write this project up in more detail. Sara, are you interested in adding these sensors to ModularSensors if so I can give the code and details for this project?

Currently these EC stations are storing the data on a sd card only. Access to these stations can be a bit challenging to say the least especially in this weather!

I recently purchased some XBee’s from Sparkfun and have been able to get them talking to each other using the serial passthrough example code loaded on a Mayfly. I have checked out the range of the XBee Pro (60 mW) and I think they have the range to talk to a central location using the XBee’s ‘out of the box’ configuration.

I am looking for any code examples for using XBee for end to end comm. Basically I want to send data to a central station station when ever the mayfly wakes up and takes
EC and temperature data.

On the hardware side has anyone had experience connecting an SMA conector to the XBee board with the attached whip antenna? The distances involved are about 1 KM LOS so will probably need some gain antennas since I am quite sure the little whip antennas wont quite cut it.

I attached a dropbox link to brief report on the deployment of the EC/temp stations

[Jim Moore]

I can feel your pain, Cal. I am going to face the problem of data upload to the the cloud or whatever on some projects that I am contemplating. I have a Mayfly water sensor on my property and the 2G is working fine. Shannon has a small box that does a 2G site survey that we used before installation of SL149

I think the larger concern will be how to upgrade all the existing Mayfly’s using 2G when that service goes the way of the dot-matrix printer!

I got some input on this question from some colleagues and in summary 3G and 4G will be overkill in terms of data rate so it would be expensive. The other option might be ORBCOMM which is a low data rate store and forward system which might be more affordable.

[Jim Moore]

Hi Stephen-

Generally all you need is a diode (1n914) and clamp resister, 10 K, to the 3.3 Volt bus. This will isolate the higher rs232 voltage from the Mayfly. This is not totally spec (the diode drop gets added to your logic levels) but should work.
Shannon can probably add to this in case he has tried the cheap and dirty solution and it doesn’t work. If not try it since these parts are less than a dollar or floating around in your electronic scrap box. Or Radio Shack if you can find a store that isn’t selling exclusively cell phones!

[Jim Moore]

I have been trying to setup the new rev 0.5 boards to run my Atlas Scientific sensors and I have been using the Mayfly_sleep example. I changed J1 to use D10 as the interupt and it didn’t work till I used attachInterrupt(2, wakeISR,CHANGE)
This didn’t work reliably until I added the pinMode(RTC_PIN, INPUT_PULLUP) back into the example code.

I now have the example code working on my rev 0.5 board but the battery voltage is 1.5.
Multiple of 2! Initiating sensor reading and logging data to SDcard….
Data Record: 2017-05-14 22:28:00,548116080,23.8,1.52
showTime = 2017-05-14 22:29:00
showTime = 2017-05-14 22:30:00
Multiple of 2! Initiating sensor reading and logging data to SDcard….
Data Record: 2017-05-14 22:30:00,548116200,23.8,1.52

This code read the battery voltage correctly on the rev 0.3 board.
Is the correct pin still A6?

[Jim Moore]

Thanks Shannon-
I got my mayfly boards today and just ordered some protoboards.

[Jim Moore]

I just ordered two Mayfly boards so they seem to be in stock. I could not find the protoshields however. Are they in stock?

[Jim Moore]

Any estimate when mayfly proto boards will be available?

[Jim Moore]

I finally solved the never-sleep problem. The problem seems to be related to the slow decay of the power to the Grove connector. With the sensor connected the decay is approximately 50ms. In the senosrSleep() function the power and rx/tx are turned off but the Vcc voltage doesn’t get a chance to decay before this function is exited which seems to cause an immediate wakeup. I added a 100ms delay to that function and now seems to work as planned.

I am not sure what causes the immediate wake up but must be related to the residual voltage on the pwr pin. With the sensor disconnected the code works with out the delay probably because there is no capacitance to hold up the voltage.

I cleaned up the code a bit and here is rev 1.0

/* This example sketch puts the Mayfly board into sleep mode. It wakes up at specific times to turn on the Atlas Scientific EZO sensors. The EZO sensor is configured to output sensor data once per second (c,1 command)which is logged to the SD card along with time stamp, board temp, and battery voltage. Note: if sleep time is greater than 1 minute the board will still wake for 100ms which is less than the turn on time of the sensor. JOM 2/9/17 added power on/off to EZO board JOM 2/12/17 downloaded ...Mod.h libraries to fix RTC interupt conflicts. Need to turn off rx and tx when putting to sleep otherwise rx/tx powers the sensor after Vcc is turned off JOM 2/13/17 Problem sensor on most of time. JOM 3/18/17 The never-sleep problem was fixed by adding a 100ms delay to the sensorsSleep() function. This allows Vcc to the sensor to decay to zero which is ~50 ms. The pwr on takes only ~5us. */ #include <Wire.h> #include <avr/sleep.h> #include <avr/wdt.h> #include <SPI.h> #include <SD.h> #include <SoftwareSerialMod.h> #include <RTCTimer.h> #include <Sodaq_DS3231.h> #include <Sodaq_PcInt_Mod.h> RTCTimer timer; #define rx 11 //D11 to Tx on EZO (white on Grove conn) #define tx 10 //D10 to Rx on EZO (yellow on Grove conn) SoftwareSerialMod myserial(rx, tx); //define how the soft serial port is going to work. String dataRec = ""; String sensorstring = "EZO data"; //a string to hold the data from the EZO product int currentminute; int n = 0; int nMax = 20; int sleepMinutes = 5; //total minutes the Mayfly is in sleep mode long currentepochtime = 0; float boardtemp; int batteryPin = A6; // to read battery voltage int batterysenseValue = 0; // variable to store the value coming from the sensor float batteryvoltage; boolean sensor_stringcomplete = false; //have we received all the data from the EZO product //RTC Interrupt pin #define RTC_PIN A7 #define RTC_INT_PERIOD EveryMinute #define SD_SS_PIN 12 //orig had pin 11 //The data log file #define FILE_NAME "datafile.txt" //Data header #define LOGGERNAME "SampleLogger" #define DATA_HEADER "DateTime_EST,Loggertime,BoardTemp_C,Battery_V" void setup() { //Initialise the serial connection Serial.begin(9600); myserial.begin(9600); //set baud rate for software serial port_3 to 9600 //if myserial active sleep doesn't work rtc.begin(); pinMode(8, OUTPUT); pinMode(9, OUTPUT); pinMode(22, OUTPUT); //Power to Grove connectors sensorstring.reserve(30); //set aside some bytes for receiving data from EZO product greenred4flash(); //blink the LEDs to show the board is on setupLogFile(); setupTimer(); //Setup timer events setupSleep(); //Setup sleep mode digitalWrite(10, false); //Turn off tx to EZO ckt digitalWrite(11, false); //Turn off rx to EZO ckt digitalWrite(22, true); //Turn on power to EZO ckt Serial.println("Power On, running: mayfly_sleep_sample1.ino"); showTime(getNow()); } void loop() { //Update the timer timer.update(); if (currentminute % sleepMinutes == 0) //will wake every minute for set delay untill condition //is satisfied { while (!sensor_stringcomplete && (n < nMax)) { recieveSensorData(); } n = 0; } delay(100); //should be less than sensor turnon time which is ~1sec //Sleep systemSleep(); } //end loop void sensorsSleep() { Serial.println("..going to sleep!"); digitalWrite(22, false); //Turn off power to EZO ckt digitalWrite(10, false); //Turn off tx to EZO ckt digitalWrite(11, false); //Turn off rx to EZO ckt delay(100); //adding delay fixed the never-sleep problem } void sensorsWake() { digitalWrite(22, true); //Turn on power to EZO ckt Serial.println("..I'm awake!"); } void recieveSensorData() { if (myserial.available() > 0) { //if we see that the EZO product has sent a character. char inchar = (char)myserial.read(); //get the char we just received sensorstring += inchar; if (inchar == '\r') { sensor_stringcomplete = true; //if the incoming character is a <CR>, set the flag n++; } } if (sensor_stringcomplete) { //if a string from the EZO product has been received //in its entirety dataRec = createDataRecord(); if (n >= 3) //don't log sensor startup response { logData(dataRec); //Save the data record to the log file } Serial.print(" "); Serial.println(dataRec); Serial.print("n= "); Serial.println(n); sensorstring = ""; //clear the string: sensor_stringcomplete = false; //reset the flag used to tell if we have received a } } String createDataRecord() { //Create a String type data record in csv format //TimeDate, Loggertime,Temp_DS, Diff1, Diff2, boardtemp String data = getDateTime(); data += ","; rtc.convertTemperature(); //convert current temperature into registers boardtemp = rtc.getTemperature(); //Read temperature sensor value batterysenseValue = analogRead(batteryPin); batteryvoltage = (3.3 / 1023.) * 1.47 * batterysenseValue; data += currentepochtime; data += ","; addFloatToString(data, boardtemp, 3, 1); //float data += ","; addFloatToString(data, batteryvoltage, 4, 2); data += " , "; //adds a comma between values data += sensorstring; //adds pH to the data string return data; } void showTime(uint32_t ts) { //Retrieve and display the current date/time String dateTime = getDateTime(); //Serial.println(dateTime); } void setupTimer() { //Schedule the wakeup every minute timer.every(1, showTime); //Instruct the RTCTimer how to get the current time reading timer.setNowCallback(getNow); } void wakeISR() { //Leave this blank } void setupSleep() { pinMode(RTC_PIN, INPUT_PULLUP); PcInt::attachInterrupt(RTC_PIN, wakeISR); //Setup the RTC in interrupt mode rtc.enableInterrupts(RTC_INT_PERIOD); //Set the sleep mode set_sleep_mode(SLEEP_MODE_PWR_DOWN); } void systemSleep() { //This method handles any sensor specific sleep setup sensorsSleep(); //Wait until the serial ports have finished transmitting Serial.flush(); // Serial1.flush(); //The next timed interrupt will not be sent until this is cleared rtc.clearINTStatus(); //Disable ADC ADCSRA &= ~_BV(ADEN); //Sleep time noInterrupts(); sleep_enable(); interrupts(); sleep_cpu(); sleep_disable(); //Enbale ADC ADCSRA |= _BV(ADEN); //This method handles any sensor specific wake setup sensorsWake(); } String getDateTime() { String dateTimeStr; //Create a DateTime object from the current time DateTime dt(rtc.makeDateTime(rtc.now().getEpoch())); currentepochtime = (dt.get()); //Unix time in seconds currentminute = (dt.minute()); //Convert it to a String dt.addToString(dateTimeStr); return dateTimeStr; } uint32_t getNow() { currentepochtime = rtc.now().getEpoch(); return currentepochtime; } void greenred4flash() { for (int i = 1; i <= 4; i++) { digitalWrite(8, HIGH); digitalWrite(9, LOW); delay(50); digitalWrite(8, LOW); digitalWrite(9, HIGH); delay(50); } digitalWrite(9, LOW); } void setupLogFile() { //Initialise the SD card if (!SD.begin(SD_SS_PIN)) { Serial.println("Error: SD card failed to initialise or is missing."); //Hang // while (true); } //Check if the file already exists bool oldFile = SD.exists(FILE_NAME); //Open the file in write mode File logFile = SD.open(FILE_NAME, FILE_WRITE); //Add header information if the file did not already exist if (!oldFile) { logFile.println(LOGGERNAME); logFile.println(DATA_HEADER); } //Close the file to save it logFile.close(); } void logData(String rec) { //Re-open the file File logFile = SD.open(FILE_NAME, FILE_WRITE); //Write the CSV data logFile.println(rec); //Close the file to save it logFile.close(); } static void addFloatToString(String & str, float val, char width, unsigned char precision) { char buffer[10]; dtostrf(val, width, precision, buffer); str += buffer; }

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/*   This example sketch puts the Mayfly board into sleep mode.  It wakes up at specific times   to turn on the Atlas Scientific EZO sensors. The EZO sensor is configured to output sensor   data once per second (c,1 command)which is logged to the SD card along with time stamp,   board temp, and battery voltage. Note: if sleep time is greater than 1 minute the board will   still wake for 100ms which is less than the turn on time of the sensor.   JOM 2/9/17 added power on/off to EZO board   JOM 2/12/17 downloaded ...Mod.h libraries to fix RTC interupt conflicts.  Need to turn off   rx and tx when putting to sleep otherwise rx/tx powers the sensor after Vcc is turned off   JOM 2/13/17 Problem sensor on most of time.   JOM 3/18/17 The never-sleep problem was fixed by adding a 100ms delay to the sensorsSleep()   function. This allows Vcc to the sensor to decay to zero which is ~50 ms.  The pwr on takes only ~5us. */   #include <Wire.h> #include <avr/sleep.h> #include <avr/wdt.h> #include <SPI.h> #include <SD.h> #include <SoftwareSerialMod.h>   #include <RTCTimer.h> #include <Sodaq_DS3231.h> #include <Sodaq_PcInt_Mod.h>   RTCTimer timer;   #define rx 11                 //D11 to Tx on EZO (white on Grove conn) #define tx 10                 //D10 to Rx on EZO (yellow on Grove conn) SoftwareSerialMod myserial(rx, tx);   //define how the soft serial port is going to work.   String dataRec = ""; String sensorstring = "EZO data";            //a string to hold the data from the EZO product   int currentminute; int n = 0; int nMax = 20; int sleepMinutes = 5;  //total minutes the Mayfly is in sleep mode long currentepochtime = 0; float boardtemp;   int batteryPin = A6;    // to read battery voltage int batterysenseValue = 0;  // variable to store the value coming from the sensor float batteryvoltage; boolean sensor_stringcomplete = false; //have we received all the data from the EZO product   //RTC Interrupt pin #define RTC_PIN A7 #define RTC_INT_PERIOD EveryMinute   #define SD_SS_PIN 12  //orig had pin 11   //The data log file #define FILE_NAME "datafile.txt"   //Data header #define LOGGERNAME "SampleLogger" #define DATA_HEADER "DateTime_EST,Loggertime,BoardTemp_C,Battery_V"   void setup() {   //Initialise the serial connection   Serial.begin(9600);   myserial.begin(9600);        //set baud rate for software serial port_3 to 9600   //if myserial active sleep doesn't work   rtc.begin();   pinMode(8, OUTPUT);   pinMode(9, OUTPUT);   pinMode(22, OUTPUT);            //Power to Grove connectors   sensorstring.reserve(30);         //set aside some bytes for receiving data from EZO product   greenred4flash();    //blink the LEDs to show the board is on   setupLogFile();   setupTimer();        //Setup timer events   setupSleep();        //Setup sleep mode   digitalWrite(10, false);         //Turn off tx to EZO ckt   digitalWrite(11, false);         //Turn off rx to EZO ckt   digitalWrite(22, true);         //Turn on power to EZO ckt     Serial.println("Power On, running: mayfly_sleep_sample1.ino");   showTime(getNow()); }   void loop() {   //Update the timer   timer.update();     if (currentminute % sleepMinutes == 0) //will wake every minute for set delay untill condition     //is satisfied   {     while (!sensor_stringcomplete && (n < nMax))     {       recieveSensorData();     }     n = 0;   }   delay(100);  //should be less than sensor turnon time which is ~1sec   //Sleep   systemSleep(); }  //end loop   void sensorsSleep() {   Serial.println("..going to sleep!");   digitalWrite(22, false);         //Turn off power to EZO ckt   digitalWrite(10, false);         //Turn off tx to EZO ckt   digitalWrite(11, false);         //Turn off rx to EZO ckt   delay(100);               //adding delay fixed the never-sleep problem }   void sensorsWake() {   digitalWrite(22, true);         //Turn on power to EZO ckt   Serial.println("..I'm awake!"); }   void recieveSensorData() {   if (myserial.available() > 0) {        //if we see that the EZO product has sent a character.     char inchar = (char)myserial.read(); //get the char we just received     sensorstring += inchar;     if (inchar == '\r') {       sensor_stringcomplete = true;     //if the incoming character is a <CR>, set the flag       n++;     }   }   if (sensor_stringcomplete) {          //if a string from the EZO product has been received     //in its entirety     dataRec = createDataRecord();     if (n >= 3)  //don't log sensor startup response     {       logData(dataRec);            //Save the data record to the log file     }     Serial.print("  ");     Serial.println(dataRec);     Serial.print("n=  ");     Serial.println(n);       sensorstring = "";    //clear the string:     sensor_stringcomplete = false;       //reset the flag used to tell if we have received a   } }   String createDataRecord() {   //Create a String type data record in csv format   //TimeDate, Loggertime,Temp_DS, Diff1, Diff2, boardtemp   String data = getDateTime();   data += ",";       rtc.convertTemperature();          //convert current temperature into registers   boardtemp = rtc.getTemperature(); //Read temperature sensor value     batterysenseValue = analogRead(batteryPin);   batteryvoltage = (3.3 / 1023.) * 1.47 * batterysenseValue;     data += currentepochtime;   data += ",";     addFloatToString(data, boardtemp, 3, 1);    //float   data += ",";   addFloatToString(data, batteryvoltage, 4, 2);   data += " , ";                 //adds a comma between values   data += sensorstring;     //adds pH to the data string     return data; }     void showTime(uint32_t ts) {   //Retrieve and display the current date/time   String dateTime = getDateTime();   //Serial.println(dateTime); }   void setupTimer() {     //Schedule the wakeup every minute   timer.every(1, showTime);     //Instruct the RTCTimer how to get the current time reading   timer.setNowCallback(getNow);   }   void wakeISR() {   //Leave this blank }   void setupSleep() {   pinMode(RTC_PIN, INPUT_PULLUP);   PcInt::attachInterrupt(RTC_PIN, wakeISR);     //Setup the RTC in interrupt mode   rtc.enableInterrupts(RTC_INT_PERIOD);     //Set the sleep mode   set_sleep_mode(SLEEP_MODE_PWR_DOWN); }   void systemSleep() {   //This method handles any sensor specific sleep setup   sensorsSleep();     //Wait until the serial ports have finished transmitting   Serial.flush();   //  Serial1.flush();     //The next timed interrupt will not be sent until this is cleared   rtc.clearINTStatus();     //Disable ADC   ADCSRA &= ~_BV(ADEN);     //Sleep time   noInterrupts();   sleep_enable();   interrupts();   sleep_cpu();   sleep_disable();     //Enbale ADC   ADCSRA |= _BV(ADEN);     //This method handles any sensor specific wake setup   sensorsWake(); }     String getDateTime() {   String dateTimeStr;     //Create a DateTime object from the current time   DateTime dt(rtc.makeDateTime(rtc.now().getEpoch()));     currentepochtime = (dt.get());    //Unix time in seconds     currentminute = (dt.minute());   //Convert it to a String   dt.addToString(dateTimeStr);   return dateTimeStr; }   uint32_t getNow() {   currentepochtime = rtc.now().getEpoch();   return currentepochtime; }   void greenred4flash() {   for (int i = 1; i <= 4; i++) {     digitalWrite(8, HIGH);     digitalWrite(9, LOW);     delay(50);     digitalWrite(8, LOW);     digitalWrite(9, HIGH);     delay(50);   }   digitalWrite(9, LOW); }     void setupLogFile() {   //Initialise the SD card   if (!SD.begin(SD_SS_PIN))   {     Serial.println("Error: SD card failed to initialise or is missing.");     //Hang     //  while (true);   }     //Check if the file already exists   bool oldFile = SD.exists(FILE_NAME);     //Open the file in write mode   File logFile = SD.open(FILE_NAME, FILE_WRITE);     //Add header information if the file did not already exist   if (!oldFile)   {     logFile.println(LOGGERNAME);     logFile.println(DATA_HEADER);   }     //Close the file to save it   logFile.close(); }     void logData(String rec) {   //Re-open the file   File logFile = SD.open(FILE_NAME, FILE_WRITE);     //Write the CSV data   logFile.println(rec);     //Close the file to save it   logFile.close(); }       static void addFloatToString(String & str, float val, char width, unsigned char precision) {   char buffer[10];   dtostrf(val, width, precision, buffer);   str += buffer; }

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