erratic data stream using serial connection to MakerPlot

I am new to serial connections, so there may be an obvious answer to this ...

I am recording data from six analog inputs to the Arduino over a serial port to MakerPlot. They plot well, but the timing is distorted ... it pauses every so often (maybe every second or so?), making a wildly distorted graph.

My data have a cycle of around 120 cycles per minute (500 ms per cycle), so I need pretty consistent readings to get a smooth curve.

I don't know these pauses are a characteristic of serial ports, of Arduino, or of MakerPlot. However, when using the built-in Arduino serial monitor, it doesn't seem to do this.

Would appreciate suggestions as to the best way to get a reliable stream of data from the Arduino, hopefully at a consistent sampling interval of around 10ms.

(I have a data-logging shield (using an SD card), but haven't put it together yet, as real-time logging and display are better, if they don't screw up the data ...)

void readpins() {
     float   V0=analogRead(A0)*5/1024.0;
      float V1=analogRead(A1)*5/1024.0;
      float V2=analogRead(A2)*5/1024.0;
      float V3=analogRead(A3)*5/1024.0;
      float V4=analogRead(A4)*5/1024.0;
      float V5=analogRead(A5)*5/1024.0;
    }
void testprint(){
  Serial.print(V0);
  Serial.print(",");
  Serial.print(V1);
  Serial.print(",");
  Serial.print(V2);
  Serial.print(",");
  Serial.print(V3);
  Serial.print(",");
  Serial.print(V4);
  Serial.print(",");
  Serial.println(V5);
 }

Thanks!

Phil

what is source impedence value? is it greater than 10kohms?
also you should try use any one of a) first conversion mode b) free running mode or c) an interrupt that is a multiple of your ADC clock all other modes will have 1/2 adc clock jitter.

A bug was found in MakerPlot which was causing this stalling. Recent releases have corrected this issue ( and others).

The latest version can be downloaded at www.makerplot.com

Sincerely,
Martin
MakerPlot Developer