[Marion]

We just finished the last of a series of tests of the Maxbotix. With the changes which Sara suggested (close the serial port after each log interval and restart it for each new consectutive interval), the sleep code does work if the sensor is continuously powered.

Setup: Maxbotix 7389 sensor with the target either stream water or a fixed/flat metal plate approx 1/2 meter on a side. Before all testing (with 2 sensors), the sensor faces were coated with a very thin coating of fluoropolymer grease (very hydrophobic) to help shed any condensation.

Results:
1. Sensor mounted over a standpipe in water. Ambient temperature near 20 C. Frequent bad data (300) with normal serial read using code originally supplied by Shannon Hicks. Sensor powered by Mayfly digital pin only when logging.

2. We suspected that there might be some interaction between the sensor and logger. Tried reading in the serial data with 50 milliseconds delay between each digit. This very slow read out of the data- have never seen this in the literature, gave a partial solution. This eliminated the bad data until fall when temperatures dropped down to about 10 C at night. Then bad data again occurred.

3. Sensor tested with a boom mount over the water or metal plate with intermittent power, but no standpipe. Results still showed some bad data points, even with traps to reread up to 20 times in the event of bad data. The bad data occurred at random times, when the temps were well above freezing and below freezing. The conclusion is that condensation on the sensor face is not the issue.

4. The final test was a 10 day test, 5 minute intervals, with sensor continuously powered independently by a separate battery power pack. During that time, the angle of the sensor from perpendicular to the target was varied from 0 degrees up to 5 degrees (to help shed potential condensation if any occurred). During that time, the temperatures ranged from as high as 15 C and as low as -5 C. Absolutely no bad data points were measured during the entire test.

Conclusions:
a. We saw no evidence that the sensor had any issue related to condensation during the tests given that there was a hydrophobic coating on the sensor face and that the bad data occurred at random temperatures as opposed to only when the temperatures were low.

b. Reading out the serial data with a pause between digits rather than at normal speed seemed to help eliminate bad data when the weather was warm. But, this did not solve the problem when cooler weather arrived in the fall.

c. There was no bad data during the testing of the sensor with continuously power independent of the Mayfly, including at temperatures well below freezing.

Recommendation: If the Maxbotix 7389 sensor is used and a criterion is to log absolutely no bad data (such as when the data is used to control a pump sampler as we intend), it is recommended that sensor power be supplied continuously by an independent power pack.

I will be happy to forward or post data files if anyone wants to see the raw data.

[Marion]

#include <SoftwareSerial_PCINT12.h> #include <Sodaq_PcInt_PCINT0.h> //sketch to log sonar data on Mayfly //this one uses either board power or a battery pack to continuously power Maxbotix #include <Wire.h> #include <avr/sleep.h> #include <avr/wdt.h> #include <SPI.h> #include <SdFat.h> SdFat SD; #include <RTCTimer.h> #include <Sodaq_DS3231.h> // const int SonarExcite = 11; // turns on switched power SoftwareSerial sonarSerial(19, -1); boolean stringComplete = false; #define READ_DELAY 1 // RTC Timer RTCTimer timer; String dataRec = ""; int currentminute; long currentepochtime = 0; float boardtemp = 0.0; int batteryPin = A6; // select the input pin for the potentiometer int batterysenseValue = 0; // variable to store the value coming from the sensor float batteryvoltage; int range_mm1; int range_mm2; int range_mm3; int range_mm4; int range_mm5; int range_mm6; int range_mm7; int range_mm8; int range_mm9; int range_mm10; int range_mm; // RTC Interrupt pin #define RTC_PIN A7 #define RTC_INT_PERIOD EveryMinute #define SD_SS_PIN 12 // The data log file #define FILE_NAME "SonicLog.txt" // Data header #define LOGGERNAME "Ultrasonic Maxbotix Sensor Datalogger" #define DATA_HEADER "DateTime,Loggertime,BoardTemp,Battery_V,SonarRange_mm 1 to 10" void setup() { // Initialise the serial connection // Serial.begin(57600); sonarSerial.begin(9600); rtc.begin(); delay(100); pinMode(8, OUTPUT); pinMode(9, OUTPUT); pinMode(18, OUTPUT); greenred4flash(); //blink the LEDs to show the board is on setupLogFile(); // Setup timer events setupTimer(); // Setup sleep mode setupSleep(); // Serial.println("Power On, running: ultrasonic_logger_example_1.ino"); // Serial.println("Power On, running: ultrasonic_logger_example_1.ino"); digitalWrite(8, HIGH); stringComplete = false; digitalWrite(18, HIGH); delay(500);//wait for board to stabilize range_mm = SonarRead();//does not add data to a string, included only for debugging digitalWrite(18, LOW); digitalWrite(8,LOW); delay (2000); } void loop() { //Update the timer timer.update(); if(currentminute % 5 == 0) { digitalWrite(8, HIGH); dataRec = createDataRecord(); stringComplete = false; delay(100); digitalWrite(18, HIGH);//turns on switched power delay(10000);//wait 15 sec for board to stabilize after startup range_mm1 = SonarRead(); stringComplete = false; delay (1000); range_mm2 = SonarRead(); stringComplete = false; delay (1000); range_mm3 = SonarRead(); stringComplete = false; delay (1000); range_mm4 = SonarRead(); stringComplete = false; delay (1000); range_mm5 = SonarRead(); stringComplete = false; delay (1000); range_mm6 = SonarRead(); stringComplete = false; delay (1000); range_mm7 = SonarRead(); stringComplete = false; delay (1000); range_mm8 = SonarRead(); stringComplete = false; delay (1000); range_mm9 = SonarRead(); stringComplete = false; delay (1000); range_mm10 = SonarRead(); stringComplete = false; delay (1000); digitalWrite(8, LOW); //following records ten data reads. dataRec += ","; dataRec += range_mm1; dataRec += ","; dataRec += range_mm2; dataRec += ","; dataRec += range_mm3; dataRec += ","; dataRec += range_mm4; dataRec += ","; dataRec += range_mm5; dataRec += ","; dataRec += range_mm6; dataRec += ","; dataRec += range_mm7; dataRec += ","; dataRec += range_mm8; dataRec += ","; dataRec += range_mm9; dataRec += ","; dataRec += range_mm10; //Save the data record to the log file logData(dataRec); //Echo the data to the serial connection //Serial.println(); //Serial.print("Data Record: "); //Serial.println(dataRec); String dataRec = ""; } systemSleep(); } 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(READ_DELAY, 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() { //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 &amp;= ~_BV(ADEN); //Sleep time noInterrupts(); sleep_enable(); interrupts(); sleep_cpu(); sleep_disable(); //Enbale ADC ADCSRA |= _BV(ADEN); } 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 &lt;= 4; i++){ digitalWrite(8, HIGH); digitalWrite(9, LOW); delay(50); digitalWrite(8, LOW); digitalWrite(9, HIGH); delay(50); } digitalWrite(9, LOW); } void setupLogFile() { // initialize the SD card at SPI_FULL_SPEED for best performance. // try SPI_HALF_SPEED if bus errors occur. if (!SD.begin(SD_SS_PIN, SPI_HALF_SPEED)) { SD.initErrorHalt(); } //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(); } 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.) * (12.7/2.7) * batterysenseValue; data += currentepochtime; data += ","; addFloatToString(data, boardtemp, 3, 1); //float data += ","; addFloatToString(data, batteryvoltage, 4, 2); return data; } static void addFloatToString(String &amp; str, float val, char width, unsigned char precision) { char buffer[10]; dtostrf(val, width, precision, buffer); str += buffer; } int SonarRead() { int result; char inData[5]; //char array to read data into int index = 0; while (sonarSerial.read() != -1) {} while (stringComplete == false) { if (sonarSerial.available()) { char rByte = sonarSerial.read(); //read serial input for "R" to mark start of data if(rByte == 'R') { //Serial.println("rByte set"); while (index &lt; 4) //read next three character for range from sensor { if (sonarSerial.available()) { delay(50); inData[index] = sonarSerial.read(); //Serial.println(inData[index]); //Debug line index++; // Increment where to write next } } inData[index] = 0x00; //add a padding byte at end for atoi() function } rByte = 0; //reset the rByte ready for next reading index = 0; // Reset index ready for next reading stringComplete = true; // Set completion of read to true result = atoi(inData); // Changes string data into an integer for use } } return result; }

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430

#include <SoftwareSerial_PCINT12.h>   #include <Sodaq_PcInt_PCINT0.h>       //sketch to log sonar data on Mayfly //this one uses either board power or a battery pack to continuously power Maxbotix #include <Wire.h> #include <avr/sleep.h> #include <avr/wdt.h>   #include <SPI.h> #include <SdFat.h> SdFat SD;   #include <RTCTimer.h> #include <Sodaq_DS3231.h>     // const int SonarExcite = 11;  // turns on switched power SoftwareSerial sonarSerial(19, -1);           boolean stringComplete = false;   #define READ_DELAY 1   // RTC Timer RTCTimer timer;   String dataRec = ""; int currentminute; long currentepochtime = 0; float boardtemp = 0.0;   int batteryPin = A6;    // select the input pin for the potentiometer int batterysenseValue = 0;  // variable to store the value coming from the sensor float batteryvoltage;   int range_mm1; int range_mm2; int range_mm3; int range_mm4; int range_mm5; int range_mm6; int range_mm7; int range_mm8; int range_mm9; int range_mm10; int range_mm;   // RTC Interrupt pin #define RTC_PIN A7 #define RTC_INT_PERIOD EveryMinute   #define SD_SS_PIN 12   // The data log file #define FILE_NAME "SonicLog.txt"   // Data header #define LOGGERNAME "Ultrasonic Maxbotix Sensor Datalogger" #define DATA_HEADER "DateTime,Loggertime,BoardTemp,Battery_V,SonarRange_mm 1 to 10"        void setup() {   // Initialise the serial connection   // Serial.begin(57600);   sonarSerial.begin(9600);   rtc.begin();   delay(100);   pinMode(8, OUTPUT);   pinMode(9, OUTPUT);      pinMode(18, OUTPUT);           greenred4flash();   //blink the LEDs to show the board is on     setupLogFile();     // Setup timer events   setupTimer();      // Setup sleep mode   setupSleep();      // Serial.println("Power On, running: ultrasonic_logger_example_1.ino");   // Serial.println("Power On, running: ultrasonic_logger_example_1.ino");           digitalWrite(8, HIGH);                stringComplete = false;                          digitalWrite(18, HIGH);                      delay(500);//wait for board to stabilize             range_mm = SonarRead();//does not add data to a string, included only for debugging                     digitalWrite(18, LOW);                     digitalWrite(8,LOW);                delay (2000); }   void loop() {        //Update the timer   timer.update();         if(currentminute % 5 == 0)     {             digitalWrite(8, HIGH);             dataRec = createDataRecord();           stringComplete = false;           delay(100);               digitalWrite(18, HIGH);//turns on switched power           delay(10000);//wait 15 sec for board to stabilize after startup           range_mm1 = SonarRead();           stringComplete = false;                        delay (1000);                      range_mm2 = SonarRead();           stringComplete = false;                        delay (1000);                      range_mm3 = SonarRead();           stringComplete = false;                        delay (1000);                      range_mm4 = SonarRead();           stringComplete = false;                        delay (1000);                      range_mm5 = SonarRead();           stringComplete = false;                        delay (1000);                      range_mm6 = SonarRead();           stringComplete = false;                        delay (1000);                      range_mm7 = SonarRead();           stringComplete = false;                        delay (1000);                      range_mm8 = SonarRead();           stringComplete = false;                        delay (1000);                      range_mm9 = SonarRead();           stringComplete = false;                        delay (1000);                      range_mm10 = SonarRead();           stringComplete = false;                        delay (1000);                      digitalWrite(8, LOW);           //following records ten data reads.         dataRec += ",";       dataRec += range_mm1;         dataRec += ",";       dataRec += range_mm2;         dataRec += ",";       dataRec += range_mm3;         dataRec += ",";       dataRec += range_mm4;         dataRec += ",";       dataRec += range_mm5;         dataRec += ",";       dataRec += range_mm6;         dataRec += ",";       dataRec += range_mm7;         dataRec += ",";       dataRec += range_mm8;         dataRec += ",";       dataRec += range_mm9;         dataRec += ",";       dataRec += range_mm10;                                                                         //Save the data record to the log file           logData(dataRec);           //Echo the data to the serial connection           //Serial.println();           //Serial.print("Data Record: ");           //Serial.println(dataRec);                       String dataRec = "";        }           systemSleep();      }        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(READ_DELAY, 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() {     //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 &amp;= ~_BV(ADEN);      //Sleep time   noInterrupts();   sleep_enable();   interrupts();   sleep_cpu();   sleep_disable();   //Enbale ADC   ADCSRA |= _BV(ADEN);    }   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 &lt;= 4; i++){   digitalWrite(8, HIGH);     digitalWrite(9, LOW);   delay(50);   digitalWrite(8, LOW);   digitalWrite(9, HIGH);   delay(50);   }   digitalWrite(9, LOW); }   void setupLogFile() {   // initialize the SD card at SPI_FULL_SPEED for best performance.   // try SPI_HALF_SPEED if bus errors occur.   if (!SD.begin(SD_SS_PIN, SPI_HALF_SPEED)) {     SD.initErrorHalt();   }   //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();   }   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.) * (12.7/2.7) * batterysenseValue;          data += currentepochtime;     data += ",";       addFloatToString(data, boardtemp, 3, 1);    //float       data += ",";       addFloatToString(data, batteryvoltage, 4, 2);        return data; }     static void addFloatToString(String &amp; str, float val, char width, unsigned char precision) {   char buffer[10];   dtostrf(val, width, precision, buffer);   str += buffer; }     int SonarRead() {     int result;   char inData[5];                                          //char array to read data into   int index = 0;      while (sonarSerial.read() != -1) {}      while (stringComplete == false) {         if (sonarSerial.available())     {              char rByte = sonarSerial.read();                     //read serial input for "R" to mark start of data       if(rByte == 'R')       {         //Serial.println("rByte set");         while (index &lt; 4)                                  //read next three character for range from sensor         {           if (sonarSerial.available())           {             delay(50);             inData[index] = sonarSerial.read();             //Serial.println(inData[index]);               //Debug line               index++;                                       // Increment where to write next           }           }         inData[index] = 0x00;                              //add a padding byte at end for atoi() function       }         rByte = 0;                                           //reset the rByte ready for next reading         index = 0;                                           // Reset index ready for next reading       stringComplete = true;                               // Set completion of read to true       result = atoi(inData); // Changes string data into an integer for use            }               }                         return result; }

[Marion]

Sensor works much better in open air suspended over water on a boom. We are now testing taking 10 separate reads at each time interval- for trouble shooting information. Although occasional intervals give 300 for all 10 reads, most of the time bad data occurs in only the first 2 or 3 reads at any interval. We are seeing intervals with some bad data values at a frequency of maybe once per day. We will test going up to 25 reads to see if that solves the problem.

The code used for testing is in the attached file. This works as desired (sleep code works) when sonar power is on D18 and signal read is on D19. Alternatively works on D10 (power) and D11 (signal). However, the sleep code does not work if sonar power is provided continuously from the 3.3 V rail. We wanted to test effect of leaving power applied to the sonar all the time to see the effect (might clear off condensation from the face?).

[Marion]

As suggested by Paul, once I had loaded IDE version 1.6.5 the communication problem was resolved. I was able to complete the installation and start up the Mayfly without any other issues.

Thanks

[Author]

Posts