Displaying waveforms of the DS1054Z oscilloscope with Processing

scope.java

/*
A processing script to display waveforms
https://gist.github.com/pklaus/d16fcffe335ce520a0eb
*/

byte data[];
int a, b;

void setup()
{
  size(1200, 768, P3D);
  background(0);
  frameRate(30);
}
 
void draw()
{
  data = loadBytes("/dev/shm/wfm.dat");
  fill(0, 32, 0, 32);
  rect(0, 0, width, height);
  stroke(32);
  for (int i = 0; i < 13 ; i++){
    line(i*100, 0, i*100, height);
  }
  for (int i = 0; i < 9 ; i++){
    line(0, i*96, width, i*96);
  }
  stroke(0);
  line(width/2, 0, width/2, height);
  line(0, height/2, width, height/2);
  stroke (128,255,128);
  if (data.length < 1) return;
  b = data[0] & 0xff;
    b = 128 - b;
  for(int i = 0; i < data.length - 1; i++)
  {
    a = b;
    b = data[i+1] & 0xff;
    b = 128 - b;
    line(i, height/2 + a*3, i+1, height/2 + b*3);
  }
  println(frameRate);
}

shm_feed.py

#!/usr/bin/env python

import time
import re

import ds1054z # https://pypi.python.org/pypi/ds1054z
from universal_usbtmc.exceptions import *

ds = ds1054z.DS1054Z('TCPIP::192.168.178.74::INSTR')
#ds = ds1054z.DS1054Z('TCPIP::192.168.178.74::5555::SOCKET')
#ds = ds1054z.DS1054Z('USB::0x1ab1::0x04ce::INSTR')
#ds = ds1054z.DS1054Z('/dev/usbtmc0', 'linux_kernel')

print("IDN:", ds.idn)

class ConnectionProblem(Exception): pass

ds.write(':WAVEFORM:SOURCE CHAN2')

start = time.perf_counter()
i = 0
ntimeout = 0
try:
    while True:
        if ntimeout > 10: raise ConnectionProblem()
        print('getting waveform {}'.format(i))
        try:
            ret = ds.query_raw(':WAVEFORM:DATA?')
            ntimeout = 0
        except UsbtmcReadTimeoutError:
            ntimeout += 1
            continue
        i += 1
        try:
            assert ret.startswith(b'#9000001200')
            vals = [int(val) for val in ret[11:-1]]
            with open('/dev/shm/wfm.dat', 'wb') as f:
                f.write(bytes(vals))
        except:
            print("Data invalid? - " + str(ret))
except KeyboardInterrupt:
    pass
except ConnectionProblem:
    print('Could not reach the device repeatedly')

end = time.perf_counter()
fmt = "Received {} waveforms in {:.3f} seconds (= {:.2f} wfm/s)"
print(fmt.format(i, end-start, i/(end-start)))