Data Logging Using a Configuration File and Calibrated Analog Inputs

Posted on Wed 4th, May 2016

• #1

This project uses two files on the SD card to layout CSV file format for data logging and read analog inputs in engineering units.
Mylog.cfg
Mycalibrations.cal
The following link lays out the object used to calibrate the analog inputs into engineering units. It was used to create the file “Mycalibrations.cal” on the SD card.
http://forum.espruino.com/conversations/286215/

The following code was used to create the log configuration file:
SaveLog.js

var LogObj1={
  Fname:"xxx.csv",
  Interval:1000, //milliseconds between samples
  items:[
    // header is text at top of column in csv file
    // cmd source for data in each column
    // can be in a different order
    // and have more or fewer items
    {header:"N",cmd:"count"},
    {header:"Date",cmd:"DMY",Args:["-","-"]},
    {header:"Time",cmd:"HMS",Args:[":",":"]},
    {header:"A0",cmd:"AR",Args:["A0",2]},
    {header:"A0",cmd:"SAR",Args:["A0",2]},
    {header:"Board Temp C",cmd:"BTC",Args:[2]},
    {header:"Board Temp F",cmd:"BTF",Args:[2]}
  ],

  count:0, // Number of lines logged
  N:10 // stop logging after count>N
}; //end LogObj1


function saveObject(myobject) {
  var Q;
  var sss=JSON.stringify(myobject);
 if (Q===undefined) {
  Q = E.openFile("Mylog.cfg", "w");
  Q.write(sss);
  Q.close();
  Q = undefined;
 }//endif
}//end doLog

saveObject(LogObj1); 
var a=require("fs").readFileSync("Mylog.cfg");
console.log(a);
console.log(' ');

The left screen when the log configuration file is created:

>echo(0);
{"Fname":"xxx.csv","Interval":1000,"items":[{"header":"N","cmd":"count"},{"header":"Date","cmd":"DMY","Args":["-","-"]},{"header":"Time","cmd":"HMS","Args":[":",":"]},{"header":"A0","cmd":"AR","Args":["A0",2]},{"header":"A0","cmd":"SAR","Args":["A0",2]},{"header":"Board Temp C","cmd":"BTC","Args":[2]},{"header":"Board Temp F","cmd":"BTF","Args":[2]}],"count":0,"N":10}
 
=undefined
>

The logging program. The test portion opens the calibration file and the configuration file and creates a calibration object and two instances of the configuration. The layout is identical (could be different) except that the filename to write, and logging interval in one is 1 second and the other is 3 seconds.
LogCSV3.js
The console output when the program executes:

>echo(0);
N,Date,Time,A0,Inlet psig,Board Temp C,Board Temp F
N,Date,Time,A0,Inlet psig,Board Temp C,Board Temp F
=undefined
1,4-4-2016,21:27:21,0.79,79.96,34.43,94.32
2,4-4-2016,21:27:22,0.79,79.96,34.62,93.93
3,4-4-2016,21:27:23,0.79,80.06,34.46,93.93
1,4-4-2016,21:27:23,0.79,79.98,34.84,93.93
4,4-4-2016,21:27:24,0.79,79.96,34.40,94.26
5,4-4-2016,21:27:25,0.79,79.96,34.25,94.32
6,4-4-2016,21:27:26,0.79,80.01,34.62,93.93
2,4-4-2016,21:27:26,0.79,79.96,34.46,93.93
7,4-4-2016,21:27:27,0.79,79.98,34.62,93.59
8,4-4-2016,21:27:28,0.79,79.98,34.22,93.93
9,4-4-2016,21:27:29,0.79,79.96,34.62,94.26
3,4-4-2016,21:27:29,0.79,79.98,34.59,93.93
10,4-4-2016,21:27:30,0.79,80.01,34.62,93.98
4,4-4-2016,21:27:32,0.79,80.01,34.25,93.93
5,4-4-2016,21:27:35,0.79,80.03,34.84,93.54
6,4-4-2016,21:27:38,0.79,79.98,35.02,94.26
7,4-4-2016,21:27:41,0.79,80.01,35.24,94.26
8,4-4-2016,21:27:44,0.79,80.06,34.40,93.93
9,4-4-2016,21:27:47,0.79,79.98,34.62,94.32
10,4-4-2016,21:27:50,0.79,79.96,34.25,94.26
>

The CSV files created are: xxx.csv and xx1.csv

6 Attachments

• #2

ClearMemory041063
Equipment: Espruino board, USB cable, WebIDE and SD card.
This program makes use of three objects saved in local modules in a WebIDE project.
The first object “CalObj” makes use of a file “Mycalibrations.cal” located on the SD card in the Espruino board.
```
{"calibrations":[
{"name":"Inlet","units":"psig","pin":"A0","slope":100.13897386464,"Intercept":-0.03419722673},
{"name":"Outlet","units":"psig","pin":"A1","slope":50,"Intercept":-25},
{"name":"Motor","units":"Amps","pin":"A2","slope":1,"Intercept":0},
{"name":"Supply","units":"Volts","pin":"A3","slope":1,"Intercept":0},
{"name":"Flow","units":"Liters/minute","pin":"A4","slope":1,"Intercept":0}
]}
```
The following link lays out the object used to calibrate the analog inputs into engineering units. It was used to create the file “Mycalibrations.cal” on the SD card.
http://forum.espruino.com/conversations/¬286215/

The second object “TimeObj.js” is used for its stopwatch function and ability to format date and time from a pattern stored in an array. See the following link.
http://forum.espruino.com/conversations/286424/

The third object “LogObj.js” uses the previous two object modules and a “.cfg” file stored on the SD card. This program uses three different “.cfg” files an produces three different “.csv” files. The program used to create the “.cfg” files is “saveLogCfgXX1.js”
One of the “.cfg” files looks like this:
```
{"Fname":"xx1.csv",
"Interval":1000,
"items":[
{"header":"N","cmd":"count"},
{"header":"Date","cmd":"DATE","Args":["M","-","D","-","Y"]},
{"header":"Time","cmd":"TIME","Args":["H",":","M",":","S"]},
{"header":"A0","cmd":"SAR","Args":["A0",2]},
{"header":"A1","cmd":"SAR","Args":["A1",2]},
{"header":"A2","cmd":"AR","Args":["A2",2]},
{"header":"Board Temp C","cmd":"BTC","Args":[2]},
{"header":"Board Temp F","cmd":"BTF","Args":[2]}
],
"count":0,
"N":10
}
```
The “Fname” is the name of the csv file to create.
The “Interval” is the milliseconds between each data sample.
The “Items” array contains records that set up the data to log to the csv file.
The “Header” is the text at the top of a column in the csv file.
The “cmd” can be “count”,“DATE”,“TIME”, “SAR”,”AR”,”BTC” or “BTF”
Date and time commands use the information in the “Args” to format the data.
AR is analog read without calibrations applied.
SAR is a calibrated analog reading. For SAR the header information comes from the calibration file.
For AR and SAR Args[0] is the pin name, and Args[1] is used in a toFixed(Args[1]) to format the data.
The BTC and BTF are the board temperature in F or C units.
Count is used to count and N is the number of samples to take

Programs to load into Project:
LogCSV6a.js, saveLogCfgXX1.js

Modules to load into Modules:
TimeObj.js, LogObj.js and CalObj.js
Files on SD card in the Espruino:
Mycalibrations.cal, Mylog1.cfg, Mylog2.dfg, and Mylog3.cfg
Files created on the SD card by this program:
Xx1.csv, xx2.csv, and xx3.csv.

LogCSV6a.js listing:
```
function ReadObjectFile(fname){
 return JSON.parse(require("fs").readFileSync(fname));
}//end ReadObjectFile



function TestIt(){
 var T= new (require("TimeObj"))();
 T.updateTime();
//start the stopwatch
 T.SWstart();
// output day of the week
 console.log(T.getDay());

 Cal=new (require("CalObj"))(ReadObjectFile("Mycalibrations.cal")); 
 Log=new (require("LogObj"))(ReadObjectFile("Mylog1.cfg"),Cal,T);
 Log1=new (require("LogObj"))(ReadObjectFile("Mylog2.cfg"),Cal,T);
 Log2=new (require("LogObj"))(ReadObjectFile("Mylog3.cfg"),Cal,T);

//Changes to the onjects can be masde
// Log1.A.Interval=3000;
// Log1.A.Fname="xx1.csv";

//start the logging 
 Log.doHeaders();
 Log.start();

 Log1.doHeaders();
 Log1.start();

 Log2.doHeaders();
 Log2.start();
// output the elapsed time  
 console.log(T.SWstop().toFixed(3)," ms");
}//end TestIt

setBusyIndicator(LED1);
TestIt();
```
and the console output:
```
>echo(0);
Fri
1680.916  ms
=undefined
xx1.csv Finished
11005.221  ms
xx2.csv Finished
21572.389  ms
xx3.csv Finished
3202
```
14 Attachments
• #3

allObjects

That's really cool stuff. Did you monitor RAM usage (with process.memory())?

• #4

ClearMemory041063

Trying it with process.memory().usage inserted.

function ReadObjectFile(fname){
 return JSON.parse(require("fs").readFileSync(fname));
}//end ReadObjectFile



function TestIt(){
var j=0;  
 console.log(j," ",process.memory().usage);j++;
 var T= new (require("TimeObj"))();
 console.log(j," ",process.memory().usage);j++;
 T.updateTime();
//start the stopwatch
 T.SWstart();
// output day of the week
 console.log(T.getDay());

 Cal=new (require("CalObj"))(ReadObjectFile("Mycalibrations.cal")); 
 console.log(j," ",process.memory().usage);j++;
 Log=new (require("LogObj"))(ReadObjectFile("Mylog1.cfg"),Cal,T);
 console.log(j," ",process.memory().usage);j++;
 Log1=new (require("LogObj"))(ReadObjectFile("Mylog2.cfg"),Cal,T);
 console.log(j," ",process.memory().usage);j++;
 Log2=new (require("LogObj"))(ReadObjectFile("Mylog3.cfg"),Cal,T);
 console.log(j," ",process.memory().usage);j++;

//Changes to the onjects can be masde
// Log1.A.Interval=3000;
// Log1.A.Fname="xx1.csv";

//start the logging 
 Log.doHeaders();
 Log.start();
 console.log(j," ",process.memory().usage);j++;

 Log1.doHeaders();
 Log1.start();
 console.log(j," ",process.memory().usage);j++;

 Log2.doHeaders();
 Log2.start();
// output the elapsed time  
 console.log(T.SWstop().toFixed(3)," ms");
 console.log(j," ",process.memory().usage);j++;
}//end TestIt

setBusyIndicator(LED1);
TestIt();

The output:

>echo(0);
0   445
1   453
Sat
2   571
3   717
4   827
5   937
6   958
7   975
418.646  ms
8   997
=undefined
xx1.csv Finished
10472.984  ms
xx2.csv Finished
20561.429  ms
xx3.csv Finished
30603.546  ms
>console.log(process.memory().usage);
957
=undefined
>

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Data Logging Using a Configuration File and Calibrated Analog Inputs

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