# PicoVNA106 — MATLAB Instrument Driver

A MATLAB class for controlling the **PicoVNA 106** vector network analyzer over a TCP/IP connection. Provides methods for triggering sweeps, acquiring S-parameters in polar form, querying frequency axes, and packaging results into an `SPARAMS` object.

---

## Requirements

- MATLAB with the **Instrument Control Toolbox**
- The **PicoVNA software** must be running on the host machine with its SCPI server active on `localhost:5025`
- The companion `SPARAMS` class (required by `readToSparamsObject`, available at https://github.com/njchorda/MATLAB-Touchstone-Reader)

---

## Installation

1. Clone or download this repository.
2. Add the folder to your MATLAB path:
   ```matlab
   addpath('/path/to/PicoVNA106');
   ```
3. Ensure the PicoVNA application is open and its SCPI server is enabled before instantiating the class.

---

## Quick Start

```matlab
% Connect to the VNA
vna = PicoVNA106();

% Trigger a single sweep and wait for completion
vna.sweep();

% Read all four S-parameters as complex polar data
[S11, S12, S21, S22] = vna.getSParams();

% Get the corresponding frequency axis in Hz
f = vna.getFreqAxis();

% Or read everything into a single SPARAMS object
S = vna.readToSparamsObject();

% Clean up
vna.deInit();
```

---

## API Reference

### Constructor

```matlab
obj = PicoVNA106()
```

Opens a TCP connection to `localhost:5025` with a default timeout of 10 seconds. The PicoVNA 5 software must already be running.

---

### Sweep Control

```matlab
vna.sweep()
```
Triggers a single sweep (`INIT`) and waits for the instrument to acknowledge completion.

```matlab
vna.setContinuousSweep()
```
Puts the instrument into continuous sweep mode (`INIT:CONT:ALL`).

---

### S-Parameter Acquisition

```matlab
[S11, S12, S21, S22] = vna.getSParams()
```
Reads all four S-parameters from the instrument buffer as **complex polar vectors**. Each value is returned as a column vector of complex doubles. **Does not trigger a new sweep** — call `sweep()` first if fresh data is needed.

```matlab
S = vna.readToSparamsObject()
```
Combines `getSParams()` and `getFreqAxis()` into a single `SPARAMS` object. Sets the reference impedance to 50 Ω and the port count to 2. The S-parameter and frequency vectors are column-oriented.

---

### Frequency Axis

```matlab
f = vna.getFreqAxis()
```
Queries the start frequency, stop frequency, and number of sweep points from the instrument and returns a linearly spaced frequency vector in Hz. Handles `kHz`, `MHz`, and `GHz` unit strings automatically.

---

### Power Level

```matlab
p = vna.getPowerLevel()
```
Returns the current stimulus power level in dBm.

```matlab
vna.setPowerLevel(p)
```
Sets the stimulus power level in dBm.

---

### Instrument Utilities

```matlab
id = vna.getID()
```
Queries the instrument identification string (`*IDN?`).

```matlab
vna.reset()
```
Sends `*RST` to reset the instrument to its default state.

```matlab
vna.selfTest()
```
Runs the built-in self-test (`*TST?`) and prints the result to the console.

```matlab
vna.setLocal()
```
Returns front-panel control to the user (`SYST:LOC`).

```matlab
vna.clearBuffer()
```
Flushes any pending data in the TCP receive buffer by reading until empty. Temporarily reduces the timeout to 0.2 s during the flush.

```matlab
retVal = vna.sendCommand(cmd)
```
Sends an arbitrary SCPI command. If the command contains `?`, it reads and returns the response string; otherwise returns `0`.

```matlab
vna.deInit()
```
Releases the TCP connection. Returns `1` on success, `0` if the connection was already invalid.

---

## Notes

- S-parameters are returned in **polar (real/imaginary) format** — the instrument sends interleaved real and imaginary doubles which the driver recombines into complex MATLAB arrays.
- `getSParams()` does **not** trigger a sweep. Always call `sweep()` before reading data if you need up-to-date measurements.
- The frequency string parser handles `kHz`, `MHz`, and `GHz` unit suffixes from the instrument response. Responses in plain Hz are not currently handled — extend `freqStrConvert` if needed.
- The default TCP timeout is 10 seconds, which may need increasing for slow sweeps (e.g. high point counts or narrow IF bandwidths).

---

## License

MIT License — see [LICENSE](LICENSE) for details.