# instrument-components — Rust test-equipment control
[](https://github.com/josh-hemphill/instrument-components-rs/actions/workflows/ci.yml)
High-level Rust control for VISA instruments: auto-discovery, IVI-inspired typed classes (DMM, PSU, function generator), and mock fixtures for CI — built on [visa-rs](https://crates.io/crates/visa-rs).
**Install:** `cargo add instrument-components`
**Import:** `use instrument::prelude::*` (the library name stays `instrument` even though the package is `instrument-components`)
## What you get
- Auto-discovery of USB, GPIB, and serial VISA resources
- Typed instrument classes with SI units (volts, amps, hertz)
- Mock transport for hardware-free CI
- Per-device comms health and optional push diagnostics
- Stable `DeviceId` for instrument replacement workflows
## Choose your path
| Test in CI without hardware | [Mock quick start](#mock-quick-start) |
| Talk to real USB/GPIB gear | [Hardware quick start](#hardware-quick-start) |
| Build an app with device pickers | [docs/discovery.md](docs/discovery.md) |
| Use async VISA I/O (opt-in) | [docs/async.md](docs/async.md) |
## Mock quick start
No VISA installation required.
```toml
[dependencies]
instrument-components = { version = "0.1", default-features = false }
```
```rust
use instrument::prelude::*;
let fixture = ScriptedFixture::builder()
.idn("Acme Corp", "SMU2602", "SN001", "1.0")
.kinds([InstrumentKind::Dmm, InstrumentKind::DcPowerSupply])
.on_query(":MEAS:VOLT:DC?", "3.300")
.build();
let catalog = DeviceCatalog::from_fixture("mock://smu-1", fixture)?;
let dmm = catalog.open_dmm("mock://smu-1")?;
let volts = dmm.measure_voltage_dc(None)?;
println!("{volts} V");
```
## Hardware quick start
1. Install [NI-VISA](https://www.ni.com/en-us/support/downloads/drivers/download.ni-visa.html) or [Keysight IO Libraries](https://www.keysight.com/us/en/lib/software-detail/computer-software/io-libraries-suite-downloads-2175637.html).
2. Add the dependency (VISA enabled by default):
```toml
[dependencies]
instrument-components = "0.1"
```
3. Discover and measure:
```rust
use instrument::prelude::*;
let catalog = Discovery::visa()?.scan()?;
catalog.print_summary();
let dmm = catalog.open_dmm(&catalog.devices_by_kind(InstrumentKind::Dmm)[0].address.raw)?;
let volts = dmm.measure_voltage_dc(None)?;
println!("{volts} V");
```
TCPIP/LXI devices usually need a manual address:
```rust
let catalog = Discovery::visa()?
.manual_address("TCPIP0::192.168.0.42::INSTR")
.scan()?;
```
See [docs/getting-started.md](docs/getting-started.md) for the full walkthrough.
## Feature flags
| `visa` | yes | VISA backend via `instrument-visa` |
| `record` | no | Record real I/O into mock scripts |
| `tokio` | no | Full async API: `AsyncScpiSession`, `AsyncDiscovery`, typed classes |
| `cross-compile` | no | Cross-compile enum repr for `visa-rs` |
| `default-features = false` | — | Mock/CI only; no native VISA link |
```toml
# CI / mock only
instrument-components = { version = "0.1", default-features = false }
# Async VISA (opt-in)
instrument-components = { version = "0.2", features = ["visa", "tokio"] }
tokio = { version = "1", features = ["rt-multi-thread", "macros"] }
```
## Async quick start
Same mock path as above, with `.await` and `AsyncDeviceCatalog`:
```toml
[dependencies]
instrument-components = { version = "0.2", default-features = false, features = ["tokio"] }
tokio = { version = "1", features = ["rt-multi-thread", "macros"] }
```
```rust
use instrument::prelude::*;
#[tokio::main]
async fn main() -> Result<()> {
let fixture = ScriptedFixture::builder()
.idn("Acme", "DMM1", "SN1", "1.0")
.kinds([InstrumentKind::Dmm])
.on_query(":MEAS:VOLT:DC?", "1.0")
.build();
let catalog = AsyncDeviceCatalog::from_fixture("mock://dmm", fixture).await?;
let mut dmm = catalog.open_dmm("mock://dmm").await?;
println!("{} V", dmm.measure_voltage_dc(None).await?);
Ok(())
}
```
See [docs/async.md](docs/async.md) for hardware async discovery and the full type map.
## Documentation
- [Getting started](docs/getting-started.md) — step-by-step setup
- [Architecture](docs/architecture.md) — crate layout and mental model
- [Discovery](docs/discovery.md) — probe policy, device assignment
- [Diagnostics](docs/diagnostics.md) — health polling and observers
- [Async I/O](docs/async.md) — tokio feature and async API
- [API overview](docs/api-overview.md) — main types reference
- [Examples](docs/examples.md) — runnable examples index
- [Contributing](CONTRIBUTING.md)
API reference on [docs.rs](https://docs.rs/instrument-components) (after first publish).
## Workspace crates
| `instrument-components` | facade | Discovery, typed classes, re-exports |
| `instrument-core` | backend | Transport, SCPI, mocks — no VISA |
| `instrument-visa` | backend | NI-VISA / Keysight VISA via visa-rs |
## Testing
```bash
# Mock path (no VISA) — runs in CI
cargo test --workspace --no-default-features
# Async mock path
cargo test -p instrument-core --features async
cargo test -p instrument-components --features tokio --no-default-features
# Hardware (local, requires VISA + instruments)
cargo test -p instrument-components --features visa -- --ignored
```
## License
Licensed under either of [Apache License, Version 2.0](LICENSE-APACHE) or [MIT License](LICENSE-MIT) at your option.