Hackdose SML-parser

A parser for SML messages as emitted by ISKRA(tm) smart meters for instance. It currently uses the peg-crate to express SML as a parser expression grammar. It also contains a mapping for OBIS numbers.

Usage

Once you have obtained the data for your SML-speaking appliance (e.g. a smart meter), you can use the library as follows:

use hackdose_sml_parser::{
    domain::AnyValue, domain::SmlMessageEnvelope, obis::Obis, parser::parse_body,
};

pub fn find_total_power(body: &[u8]) -> Option<i32> {
    let result = parse_body(body);
    let result = result.ok()?;
    for list in result.messages {
        match list {
            SmlMessageEnvelope::GetOpenResponse(_) => continue,
            SmlMessageEnvelope::GetListResponse(body) => {
                let values = &body.value_list;
                let usage = values.iter().find(|value| {
                    value.object_name == Obis::SumActiveInstantaneousPower.obis_number()
                });

                if let Some(usage) = usage {
                    if let AnyValue::Signed(value) = usage.value {
                        return Some(value as i32);
                    }
                }
            }
            SmlMessageEnvelope::GetCloseResponse => continue,
        }
    }
    return None;
}

Acknowledgements

Most of the work inside the library is actually performed by Kevin Mehall's peg crate. I am also indebted to Stefan Weigert's great blog post about the SML protocol which enabled me to develop the grammar incrementally rather than reading the whole 80 page specification in the first place.

Contributions

Any contributions are highly appreciated. I published this library (which is part of the yet-to-be-published hackdose project) to save everyone the work to implement yet another parser for this hard-to-read binary protocol and to focus on more interesting tasks.

License

This crate is dual-licensed under MIT and Apache 2 license at your choice.