Derivated versions

Lock-in+PID H

Harmonic lock-in up to 50 kHz, PID filters and lock control.

Lock-in+PID SQ

Version of Lock-in+PID with only the square (fast) lock-in.

Lock-in+PID H HF

High frequency version of Lock-in+PID H, up to 1 MHz.

Lock-in+PID H2

Two lock-in demodulators sharing the same local oscillator.

Here you can find other works and versions related with this App. Most of them are just the same application but with slight modifications.

2.x versions: they were redesigned by porting the original FPGA designs onto the base design of RedPitaya-FPGA Release_2025.2 (tag 2.07-48, branch origin/Release-2025.2), which is suitable for the Red Pitaya Ecosystem 2.0. The FPGA is built with Vivado 2020.1.

Which version should I download?

2.x → Red Pitaya Ecosystem 2.0 (e.g. RedPitaya_OS_2.04; tested on 2.04-35).
0.x → 0.9x / 1.0 ecosystems.

All versions

Lock-in+PID H

Harmonic version of Lock-in+PID. It includes a harmonic lock-in up to 50 kHz, PID filters and lock control.

This version of the App doesn’t include the square Lock-in. That frees some “physical surface” of the FPGA to implement other features.

The new features are:

Modulation added on outputs: In the Auxiliar tab of the Lock-in instrument you can switch on/off the modulation signal cos_ref to be added to the signal already chosen for each port. A -1 value means off and any other value is the relative amplitude with respect to 8191 int == 1 Vpp.
Enhanced amplification: The X and Y signals can now be amplified by x524288 (x512k). This enables the possibility to measure signals that are far below the resolution limit (~1V/8192).
Red Pitaya Ecosystem 2.0: since v0.3.9 the App was expected to work on the 2.0 ecosystem, but some bugs were found in that implementation (v0.3.10 and v0.3.11 fixed several of them, see the ChangeLog). The new 2.x versions are based on the FPGA design of RedPitaya-FPGA Release_2025.2, suitable for the 2.0 ecosystem, and they seem to work without major problems.

The lower physical surface load may correct some cross-talking problems between signals that happened on some devices in the Lock-in+PID App.

The source code can be found in the github rp_lock-in_pid_h repository.

Downloads:

For	Downloads
Ecosystem 2.0
Ecosystems 0.9x / 1.0

All releases are also available in github
ChangeLog in the project page

Lock-in+PID SQ

Version of Lock-in+PID with only the square (fast) lock-in. It takes the Lock-in+PID H App and replaces the harmonic modulation with square modulation, like the one of the original Lock-in+PID: a square local oscillator with reference and quadrature outputs up to 31.25 MHz and a square lock-in, while keeping the features of the harmonic App (modulation added to the control signals, two PIDs, ramp, lock control run by the FPGA, streaming and HTTP remote control).

It is only available as a 2.x version, for the Red Pitaya Ecosystem 2.0.

The source code can be found in the github rp_lock-in_pid_sq repository.

Downloads:

For	Downloads
Ecosystem 2.0

Lock-in+PID H HF

High Frequency version of Lock-in+PID H. It is a copy of that project with only one change: the harmonic modulation signal frequency can be set from 60 Hz to 1 MHz.

The source code can be found in the github rp_lock-in_pid_h_hf repository.

Downloads:

For	Downloads
Ecosystem 2.0
Ecosystems 0.9x / 1.0

Lock-in+PID H2

Based on Lock-in+PID H, this version includes two lock-in demodulators that share the same local oscillator, PID filters and lock control.

Features:

Two lock-in amplifiers
In-phase and quadrature demodulation
- Demodulation for arbitrary phase
- Demodulation for double and triple frequency
Two PID filters, for loop back stabilization
Ramp/Scan controller for response analysis
Lock control for automatic scan-stop / PID start
Streaming system for continued acquisition of two channels
Remote control through HTTP API

The source code can be found in the github rp_lock-in_pid_h2 repository.

Downloads: