gnss-protos 0.0.1

GNSS protos encoder and decoder
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144

//! GPS / QZSS protocol

/// GPS uses 30 bit data words, and is not aligned.
pub const GPS_WORD_SIZE: usize = 30;

/// Minimal allocation to encode a correct GPS data frame.
pub const GPS_MIN_SIZE: usize = GPS_WORD_SIZE * 10;

mod bytes;
mod decoder;
mod errors;
mod frame1;
mod frame2;
mod frame3;
mod frame_id;
mod how;
mod tlm;

pub use bytes::GpsDataByte;
pub use decoder::GpsQzssDecoder;
pub use errors::GpsError;
pub use frame_id::GpsQzssFrameId;
pub use how::GpsQzssHow;
pub use tlm::GpsQzssTelemetry;

pub use frame1::GpsQzssFrame1;
pub use frame2::GpsQzssFrame2;
pub use frame3::GpsQzssFrame3;

/// GPS / QZSS interpreted frame.
#[derive(Debug, Copy, Clone, PartialEq)]
pub struct GpsQzssFrame {
    /// [GpsQzssHow] describes following frame.
    pub how: GpsQzssHow,

    /// [GpsQzssTelemetry] describes following frame.
    pub telemetry: GpsQzssTelemetry,

    /// [GpsQzssSubframe] depends on associated How.
    pub subframe: GpsQzssSubframe,
}

/// GPS / QZSS Interpreted subframes
#[derive(Debug, Copy, Clone, PartialEq)]
pub enum GpsQzssSubframe {
    /// GPS Ephemeris Frame #1
    Ephemeris1(GpsQzssFrame1),

    /// GPS Ephemeris Frame #2
    Ephemeris2(GpsQzssFrame2),

    /// GPS Ephemeris Frame #3
    Ephemeris3(GpsQzssFrame3),
}

impl Default for GpsQzssSubframe {
    fn default() -> Self {
        Self::Ephemeris1(Default::default())
    }
}

impl GpsQzssSubframe {
    /// Unwraps self as [GpsQzssFrame1] reference (if feasible)
    pub fn as_eph1(&self) -> Option<&GpsQzssFrame1> {
        match self {
            Self::Ephemeris1(frame) => Some(frame),
            _ => None,
        }
    }

    /// Unwraps self as mutable [GpsQzssFrame1] reference (if feasible)
    pub fn as_mut_eph1(&mut self) -> Option<&mut GpsQzssFrame1> {
        match self {
            Self::Ephemeris1(frame) => Some(frame),
            _ => None,
        }
    }

    /// Unwraps self as [GpsQzssFrame2] reference (if feasible)
    pub fn as_eph2(&self) -> Option<&GpsQzssFrame2> {
        match self {
            Self::Ephemeris2(frame) => Some(frame),
            _ => None,
        }
    }

    /// Unwraps self as [GpsQzssFrame2] reference (if feasible)
    pub fn as_mut_eph2(&mut self) -> Option<&mut GpsQzssFrame2> {
        match self {
            Self::Ephemeris2(frame) => Some(frame),
            _ => None,
        }
    }

    /// Unwraps self as [GpsQzssFrame3] reference (if feasible)
    pub fn as_eph3(&self) -> Option<&GpsQzssFrame3> {
        match self {
            Self::Ephemeris3(frame) => Some(frame),
            _ => None,
        }
    }

    /// Unwraps self as [GpsQzssFrame3] reference (if feasible)
    pub fn as_mut_eph3(&mut self) -> Option<&mut GpsQzssFrame3> {
        match self {
            Self::Ephemeris3(frame) => Some(frame),
            _ => None,
        }
    }
}

// /// Verifies 24-bit LSB (right aligned) parity
// pub(crate) fn check_parity(value: u32) -> bool {
//     let data = value >> 6;
//     let expected = parity_encoding(data);
//     let parity = (value & 0x3f) as u8;
//
//     if expected == parity {
//         true
//     } else {
//         #[cfg(feature = "log")]
//         error!(
//             "GPS: parity error - expected 0x{:02X} - got 0x{:02X}",
//             expected, parity
//         );
//
//         false
//     }
// }
//
// /// Encodes 24-bit LSB into 6 bit parity (right aligned!)
// pub(crate) fn parity_encoding(value: u32) -> u8 {
//     let generator = 0x61_u32;
//     let mut reg = value << 6;
//
//     for _ in 0..24 {
//         if reg & (1 << 29) != 0 {
//             reg ^= generator << 23;
//         }
//         reg <<= 1;
//     }
//
//     ((reg >> 30) & 0x3f) as u8
// }