xy-modbus

no_std Modbus-RTU driver for the XY-series programmable buck converters (XY7025, XY6020L, XY6015, XY-SK60, XY-SK120, XY-SK120X). These modules share a common register layout — the differences between models are mechanical (max V/A/W), not protocol.

Hardware verification: only the XY7025 has been tested against real hardware (see examples/esp32c6-test/). Other models are supported on the basis of the shared register layout documented by third-party reverse engineering, but are unverified.

Usage

use xy_modbus::{Model, SafetyLimits, Xy};

let mut xy = Xy::new(my_transport, Model::Xy7025);

xy.set_protection(SafetyLimits { lvp_v: 22.0, ovp_v: 15.0, ocp_a: 15.0 })?;
xy.set_voltage(13.5)?;
xy.set_current_limit(10.0)?;
xy.set_output(true)?;

let s = xy.read_status()?;

Model selects per-register scales for I-OUT, POWER, S-OCP, S-OPP — the wrong family silently shifts current and power readings by 10×. Call xy.verify_model()? at boot to catch a misconfiguration against the device's MODEL register.

Transport

The default embedded-io feature ships a UartTransport over any BlockingRead + embedded_io::Write pair. For esp-idf-hal, enable the esp-idf-hal feature and use Xy::from_esp_uart(uart, model). To bring your own, implement [ModbusTransport] directly — the framing module exposes the on-wire codec.

The transport implementer owns UART timing. The XY-series wants ~50 ms between frames and ~500 ms response window; see DATASHEET.md §2.

Cargo features

Boot / safety policy

This crate exposes the device protocol; it intentionally does not prescribe a power-on / fault-recovery policy. See DATASHEET.md §7 for the recommended bring-up checklist (program protection before raising V-SET, force OUTPUT_EN off until verification passes, etc.).

References

• DATASHEET.md — full register map, CRC algorithm, wire-level examples, known firmware quirks.
• examples/esp32c6-test/ — on-device 26-test sweep against a real XY7025 over UART, snapshots and restores every writable register.
• API reference on docs.rs.

License

Licensed under either of MIT or Apache-2.0 at your option.