A WIFI Datalogger for Espruino PICO

Using the ringMod.js Module

Assuming that the ringMod.js module is located in th emodules folder of the WEBide sandbox.

Require the module in your code and for convience use a variable to specify the length of the rinf buffers.

var R=require('ringMod');
var dsize=432;

Declare an array of pointers to instances of ringMOD and then create the instances

For example:

var data=[];
data.push(new R("Date",dsize,Array,1,1,0,gettime,null,­datestring,0));
data.push(new R("Temp F",dsize,Int16Array,100,9/5,32,E.getTemp­erature,null,tofixed,2));
data.push(new R("Temp C",dsize,Int16Array,100,1,0,E.getTempera­ture,null));
data.push(new R("Flow l/s",dsize,Int16Array,4096,1,0,analogRea­d,pinB1,tofixed,2));
data.push(new R("Pump",dsize,Int8Array,1,1,0,digitalRe­ad,pinB3,tofixed,0));
data.push(new R("dhtTemp C",dsize,Int16Array,100,1,0,getTemp,null­));
data.push(new R("dhtRH %",dsize,Int16Array,100,1,0,getRH,null))­;

The fields used when creating instances of ringMOD

ring(hname,size,type,mult,slope,intercep­t,logfunc,lfargs,format,fargs){

1. hname - a string that is used for the column title in the final spreadsheet
   
2. size - the length of the ring buffer
   
3. type - the data type used to store the data. Examples Int16Array, Int8Array etv
   
4. mult - multiplies the raw data before storage, divides the stored value before using
   
5. slope - the linear regression slope used to scale raw values into engineering units (non-zero) If in doubt use 1.0
   
6. intercept - the linear regression intercept used to scale raw values into engineering units (try 0.0)
   

7. logfunc - name the function or helper function used to obtain the raw data. Examples:

   function gettime(a){
   return clk.getDate();
   }
   

8. lfargs - any argument needed to complte the logfunc. Example logfunc= "analogRead" and lgargs= B7, if not needed use null

9. format - name of helper function used to format the data Examples:

   function datestring(a){
   //  console.log(a);
   return Date(a).toString();
   }
   
   function tofixed(a,b){
   return(a.toFixed(b));
   }
   

10. fargs - argument used with the format function: For example format =tofixed and fargs=2

Inserting the data

Note the logflag used to suspend logging until the clock etc are ready to log.

function log() {
 var i;
 if(logflag>0){
  for(i=0;i<data.length;i++)data[i].insert­();
   digitalWrite(LED1,l=!l);
 }
}

Logging the data

The DHT22 returns data in a callback so call it first and in the callback save the DHT data and do the log()

// Do the logging at loginterval in ms
setInterval(function(){
dht.read(function (a){
 DHTt= a.temp;
 DHTrh= a.rh;
//  console.log("Temp is ",getTemp());
//  console.log("RH is ",getRH());
 log();
});
},loginterval);

The DHT temporary storage variables and the logfunct helper functions

var DHTt,DHTrh;
function getTemp(){return DHTt;}
function getRH(){return DHTrh;}

Creating the CSV data from the data array

The process.memoy() commands fix a bug that the cutting edge version of Espruino has fixed.

Send 10 lines at a time in the drain function to keep from using too much memory at a time.

function onPageRequest(req, res) { 
    var i=0;
    var ii=0;
    var j=0;
    var sss="";
  var a = url.parse(req.url, true);
if (a.pathname.substr(-1)=="/") { // a slash at the end
    res.writeHead(200, {'Content-Type': 'text/html'});
// substitute your own html here
// maybe a button to clear or reset the data log on the Pico
    res.write(page1+DweetID+page2);
process.memory(); 
    res.end();                                
}else{ //filename.csv after the URL slash to do csv files
process.memory(); 
console.log("dl");
    res.writeHead(200, {'Content-Type': 'text/csv'});
//write csv file header
     res.write("Station Name,"+DweetID+"\r");
     res.write("Download Time,"+clk.getDate().toString()+"\r");
     res.write("\r");
//write the column headers for the csv file
  for(j=0;j<data.length;j++)sss+=data[j].h­name+",";
  sss=sss.slice(0,sss.length-1)+'\r';
//  console.log("N,",sss);
  res.write("N,"+sss);
  i=0;j=0;
// send the data
  res.on('drain',function(){
process.memory(); ////////////////////////////////////////­/
    if(j>=data[0].cnt){ //logdata.length){ 
    console.log("rend1");
    res.end();
   }else{
  for(i=j;i<j+10;i++){
    if(i<data[0].cnt){ 
  sss="";
     for(ii=0;ii<data.length;ii++)
      sss=sss+data[ii].getDatum(i)+",";
     sss=sss.slice(0,sss.length-1)+'\r';
     res.write(i.toString()+","+sss);
     }else{
process.memory(); ////////////////////////////////////////­/
      console.log("rend2");
      if(j){
        res.end();
        j=0;
      }//end if j  
     }
    }//next i
    j+=10;
   }//end else
  });//end on drain
}//end else
 res.on('close', function() {});//console.log("t2close");  });
 req.on('data',function(data){});//,data)­;});
 req.on('error',function(){});//console.l­og("reqerr");});
 req.on('close',function(){});//console.l­og("reqcls");});
}//end onPagerequest