Just a quick note we have today:

A day or two ago Borut was coming up with some surprising results. He was using Red Pitaya for some slow measurements. Namely, he was checking the temperature regulation and stabilization in one of the devices in his lab. To be quick he simply grabbed one red one, recycled some code and hit the measurements.

Slow dynamics allowed for some averaging, yet we were surprised to hear the resolution of his measurements had been at the order of magnitude of 0.001 K. Have a look at the long term graph yourself and check then the magnified section!

There was no particular code development involved – a simple Octave script did the job quite well. We speak about running the acquisitions in the loop over SSH. Acquire.m routine was mentioned earlier in our blogs and is available from GitHub repository. As for the illustration – the acquisition part (just a segment of the script):

for jxx=1:1e6

command=[‘plink -l root -pw root ‘,ip_addr,’ “/opt/bin/acquire ‘,num2str(samps),’ ‘,num2str(dec),’ > /tmp/acq_tmp.txt”‘];

=system(command);

here=pwd;
%Copy file to current Matlab directory
command2=[‘pscp -pw root root@’,ip_addr,’:/tmp/acq_tmp.txt ‘,here];

=system(command2);

data=load(‘acq_tmp.txt’);
ave=(mean(data)-dc_cal)/8191*1.078*10;
tt=time-time0;
ttt=[ttt tt];
avs=[avs; ave(1)];

%Temperature conversion

R10=200e3;
Vref=1.25;
I2=1/10e3;
Rser=4.3e3;

I0=(avs-Vref)/R10; ….

And yes, the sensor: the NTC thermistor is rather well defined, its size is suitable for this kind of measurements.

This is it for today – we promised to be short. In fact it seems that precise slow measurements are no problem for Red Pitaya.

Check this page again – we are eager to report about the Red Pitaya demo at FPL conference next week.