Red Pitaya interview

nice pictures of the connectors at the bottom!

Never heard of it before. Looks awesome!

It's a good time to be a hobbiest. With Rigol scopes coming in under $400, Saleae doing great things with logic analyzers, and these guys making signal analysis and generation available to serious DIYers... man.. we've come a long way. 8)

I am interested if they make an open source lock-in amplifier with the two channel analog inputs. I made some progress in that direction using NI hardware and labview, then I graduated. I wish someone makes a lock-in amplifier app. An off-the-shelf amplifier device costs over $2K. I hope their ADC has enough gain (should be why not) to amplify millivolts.

This is very interesting to my research side. Equipment has always been expensive.

I don't like microusb for power though, flimsy!
The two symmetrical 2-row connectors are good to look at but they may want to put some keys in them so people don't accidentally plug cables into the wrong port.

liudr:
I am interested if they make an open source lock-in amplifier with the two channel analog inputs. I made some progress in that direction using NI hardware and labview, then I graduated. I wish someone makes a lock-in amplifier app. An off-the-shelf amplifier device costs over $2K. I hope their ADC has enough gain (should be why not) to amplify millivolts.

This is very interesting to my research side. Equipment has always been expensive.

I'm also interested in lock-in amplifier especially for Arduino microcontroller based. Could you share your work before using NI hardware and Labview. Currently I'm trying to miniaturize the function of commercial lock-in amplifier (NF LI-5640) in microfluidic application. However, no outstanding results come out.

I was using an NI ad converter and I didnt finish the project. This red pitaya could be used for the same purpose. It is still a bit expensive. I wil consider one if it is around 200usd. Try google sound card lockin amplifier. Some people managed to make lockins using high quality sound cards. Frequency is low.

Lock-in amplifier on Red Pitaya? Why not!
Well seriously: the idea of its implementation on Red Pitaya seems great. All resources are there - including the reference generator. 60/10 MHz BW (125 Msps) seems more than sufficient, the complete pair is in place already (14bit DAC/ADC), PLL - can be realized in several ways and then the DSP part would have to be done.
Apparently the fact that it has not been implemented yet is just due to the fact that lock-in amps are not as frequently used as scopes, spectrum analyzers and similar, so first applications rather naturally had to cover that part.
In any case - the workload to complete the lock-in amplifier is not to be underestimated.
rokH

A lock-in is a physics research apparatus while a scope is EE lab equipment and generic lab equipment. They certainly put priority on that. Not sure when I can see lock-in implemented on red pitaya. It is, after all, mainly for engineering.

Agreed – semi. Found them both, scope and lock-in, very useful in physics experiments, lock-in always in somewhat special photoacoustics setups and scope, yes, mostly in a rather generic use. Still it does not impair the feasibility of lock-in amplifier instrument implementation on RedPitaya.
I am speaking of reference generation, (most probably) digital PLL and DSP alowing for in and out-of-phase component sampling – i.e. two phase lock-in.
Handling of I's and Q's was shown already (script) – even though offline and for a different purpose. That is right – for lock-in the implementation on FPGA is a must in order to realize longer sampling. Resources are enough on red pitaya's Zynq 7010 to do it. As said, it's feasible, it is all just a matter of efforts... as always :expressionless: