First implementation only sending.

This commit is contained in:
Max Känner 2023-12-31 00:44:44 +01:00
parent 451bab2625
commit f912c03661
5 changed files with 271 additions and 0 deletions

5
.gitignore vendored
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@ -14,3 +14,8 @@ Cargo.lock
# MSVC Windows builds of rustc generate these, which store debugging information # MSVC Windows builds of rustc generate these, which store debugging information
*.pdb *.pdb
# Added by cargo
/target

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Cargo.toml Normal file
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[package]
name = "dynamixel"
version = "0.1.0"
edition = "2021"
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[lints.clippy]
pedantic = "warn"
nursery = "warn"
unwrap_used = "deny"
expect_used = "deny"
[dependencies]

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src/error.rs Normal file
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#[derive(Debug, PartialEq, Eq, Clone, Copy)]
pub enum Error {
/// Failed to process the sent instruction packet
Result,
/// Undefined instruction has been used
Instruction,
/// CRC of the sent packet does not match
Crc,
/// Data to be written in the corresponding address is outside the range of the minimum /
/// maximum value
DataRange,
/// Attempt to write data that is shorter than the data length of the corresponding address
DataLength,
/// Data to be written in the corresponding address is outside of the limit value
DataLimit,
/// Access error (write to read only, read from write only, write to rom in rom lock)
Access,
/// There is some hardware issue with the device. Check hardware error status for details.
Hardware,
/// An unknown error code was returned
Unknown,
/// The buffer is to small
BufferSize,
}
impl Error {
/// Converts the error byte from a status packet into a rust result.
const fn from_byte(byte: u8) -> Result<(), Self> {
match byte & 0x7F {
0 if byte & 0x80 == 0 => Ok(()),
0 => Err(Self::Hardware),
1 => Err(Self::Result),
2 => Err(Self::Instruction),
3 => Err(Self::Crc),
4 => Err(Self::DataRange),
5 => Err(Self::DataLength),
6 => Err(Self::DataLimit),
7 => Err(Self::Access),
_ => Err(Self::Unknown), // This shouldn't be possible
}
}
}

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src/instruction.rs Normal file
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use crate::error::Error;
/// An instruction packet sent from the host to the servo.
///
/// Structure:
/// ```text
/// 0xFF 0xFF 0xFD 0x00 ID Len_L Len_H Instruction Param1 … ParamN CRC_L CRC_H
/// ```
#[derive(Debug)]
pub struct Packet<'a> {
/// which servo to talk to
pub id: u8,
/// what to send to the servo
pub instruction: Instruction<'a>,
}
#[derive(Debug)]
pub enum Instruction<'a> {
Ping,
Read { addr: u16, len: u16 },
Write { addr: u16, data: &'a [u8] },
RegWrite { addr: u16, data: &'a [u8] },
Action,
FactoryReset(ResetType),
Reboot,
Clear,
ControlTableBackup(BackupDirection),
SyncRead { addr: u16, len: u16, ids: &'a [u8] },
SyncWrite { addr: u16, len: u16, data: &'a [u8] },
FastSyncRead { addr: u16, len: u16, ids: &'a [u8] },
BulkRead { data: &'a [u8] },
BulkWrite { data: &'a [u8] },
FastBulkRead { data: &'a [u8] },
}
#[derive(Debug, Clone, Copy)]
pub enum ResetType {
All,
AllExceptId,
AllExceptIdBaud,
}
#[derive(Debug, Clone, Copy)]
pub enum BackupDirection {
Store,
Restore,
}
impl<'a> Packet<'a> {
/// writes the instruction into the provided buffer.
///
/// # Errors
///
/// This function will return an error if the provided buffer isn't big enough
pub fn to_bytes<'b>(&self, buffer: &'b mut [u8]) -> Result<&'b mut [u8], Error> {
if buffer.len() < 10 {
return Err(Error::BufferSize);
}
buffer[..8].copy_from_slice(&[
0xFF,
0xFF,
0xFD,
0x00,
self.id,
0x00,
0x00,
self.instruction.number(),
]);
let len = self.instruction.insert_parameters(&mut buffer[8..])?;
buffer[5..7].copy_from_slice(&(len + 3).to_le_bytes());
let total_length = len as usize + 10;
// let crc = Self::CRC.checksum(&buffer[..total_length - 2]);
let crc = Self::crc(&buffer[..total_length - 2]);
buffer[total_length - 2..total_length].copy_from_slice(&crc.to_le_bytes());
Ok(&mut buffer[..total_length])
}
fn crc(buffer: &[u8]) -> u16 {
const CRC_TABLE: [u16; 256] = [
0x0000, 0x8005, 0x800F, 0x000A, 0x801B, 0x001E, 0x0014, 0x8011, 0x8033, 0x0036, 0x003C,
0x8039, 0x0028, 0x802D, 0x8027, 0x0022, 0x8063, 0x0066, 0x006C, 0x8069, 0x0078, 0x807D,
0x8077, 0x0072, 0x0050, 0x8055, 0x805F, 0x005A, 0x804B, 0x004E, 0x0044, 0x8041, 0x80C3,
0x00C6, 0x00CC, 0x80C9, 0x00D8, 0x80DD, 0x80D7, 0x00D2, 0x00F0, 0x80F5, 0x80FF, 0x00FA,
0x80EB, 0x00EE, 0x00E4, 0x80E1, 0x00A0, 0x80A5, 0x80AF, 0x00AA, 0x80BB, 0x00BE, 0x00B4,
0x80B1, 0x8093, 0x0096, 0x009C, 0x8099, 0x0088, 0x808D, 0x8087, 0x0082, 0x8183, 0x0186,
0x018C, 0x8189, 0x0198, 0x819D, 0x8197, 0x0192, 0x01B0, 0x81B5, 0x81BF, 0x01BA, 0x81AB,
0x01AE, 0x01A4, 0x81A1, 0x01E0, 0x81E5, 0x81EF, 0x01EA, 0x81FB, 0x01FE, 0x01F4, 0x81F1,
0x81D3, 0x01D6, 0x01DC, 0x81D9, 0x01C8, 0x81CD, 0x81C7, 0x01C2, 0x0140, 0x8145, 0x814F,
0x014A, 0x815B, 0x015E, 0x0154, 0x8151, 0x8173, 0x0176, 0x017C, 0x8179, 0x0168, 0x816D,
0x8167, 0x0162, 0x8123, 0x0126, 0x012C, 0x8129, 0x0138, 0x813D, 0x8137, 0x0132, 0x0110,
0x8115, 0x811F, 0x011A, 0x810B, 0x010E, 0x0104, 0x8101, 0x8303, 0x0306, 0x030C, 0x8309,
0x0318, 0x831D, 0x8317, 0x0312, 0x0330, 0x8335, 0x833F, 0x033A, 0x832B, 0x032E, 0x0324,
0x8321, 0x0360, 0x8365, 0x836F, 0x036A, 0x837B, 0x037E, 0x0374, 0x8371, 0x8353, 0x0356,
0x035C, 0x8359, 0x0348, 0x834D, 0x8347, 0x0342, 0x03C0, 0x83C5, 0x83CF, 0x03CA, 0x83DB,
0x03DE, 0x03D4, 0x83D1, 0x83F3, 0x03F6, 0x03FC, 0x83F9, 0x03E8, 0x83ED, 0x83E7, 0x03E2,
0x83A3, 0x03A6, 0x03AC, 0x83A9, 0x03B8, 0x83BD, 0x83B7, 0x03B2, 0x0390, 0x8395, 0x839F,
0x039A, 0x838B, 0x038E, 0x0384, 0x8381, 0x0280, 0x8285, 0x828F, 0x028A, 0x829B, 0x029E,
0x0294, 0x8291, 0x82B3, 0x02B6, 0x02BC, 0x82B9, 0x02A8, 0x82AD, 0x82A7, 0x02A2, 0x82E3,
0x02E6, 0x02EC, 0x82E9, 0x02F8, 0x82FD, 0x82F7, 0x02F2, 0x02D0, 0x82D5, 0x82DF, 0x02DA,
0x82CB, 0x02CE, 0x02C4, 0x82C1, 0x8243, 0x0246, 0x024C, 0x8249, 0x0258, 0x825D, 0x8257,
0x0252, 0x0270, 0x8275, 0x827F, 0x027A, 0x826B, 0x026E, 0x0264, 0x8261, 0x0220, 0x8225,
0x822F, 0x022A, 0x823B, 0x023E, 0x0234, 0x8231, 0x8213, 0x0216, 0x021C, 0x8219, 0x0208,
0x820D, 0x8207, 0x0202,
];
let mut crc_acc = 0u16;
for byte in buffer {
let i = (crc_acc >> 8) as u8 ^ byte;
crc_acc = (crc_acc << 8) ^ CRC_TABLE[i as usize];
}
crc_acc
}
}
impl<'a> Instruction<'a> {
const fn number(&self) -> u8 {
match self {
Self::Ping => 0x01,
Self::Read { addr: _, len: _ } => 0x02,
Self::Write { addr: _, data: _ } => 0x03,
Self::RegWrite { addr: _, data: _ } => 0x04,
Self::Action => 0x05,
Self::FactoryReset(_) => 0x06,
Self::Reboot => 0x08,
Self::Clear => 0x10,
Self::ControlTableBackup(_) => 0x20,
Self::SyncRead {
addr: _,
len: _,
ids: _,
} => 0x82,
Self::SyncWrite {
addr: _,
len: _,
data: _,
} => 0x83,
Self::FastSyncRead {
addr: _,
len: _,
ids: _,
} => 0x8A,
Self::BulkRead { data: _ } => 0x92,
Self::BulkWrite { data: _ } => 0x93,
Self::FastBulkRead { data: _ } => 0x9A,
}
}
fn insert_parameters(&self, buffer: &mut [u8]) -> Result<u16, Error> {
use Instruction::{
Action, BulkRead, BulkWrite, Clear, ControlTableBackup, FactoryReset, FastBulkRead,
FastSyncRead, Ping, Read, Reboot, RegWrite, SyncRead, SyncWrite, Write,
};
match self {
Ping | Action | Reboot => Ok(0),
Read { addr, len } if buffer.len() >= 4 => {
buffer[..2].copy_from_slice(&addr.to_le_bytes());
buffer[2..4].copy_from_slice(&len.to_le_bytes());
Ok(4)
}
Write { addr, data } | RegWrite { addr, data } if buffer.len() >= 2 + data.len() => {
buffer[..2].copy_from_slice(&addr.to_le_bytes());
buffer[2..data.len() + 2].copy_from_slice(data);
Ok(2 + u16::try_from(data.len()).map_err(|_| Error::Unknown)?)
}
FactoryReset(reset) if !buffer.is_empty() => {
buffer[0] = match reset {
ResetType::All => 0xFF,
ResetType::AllExceptId => 0x01,
ResetType::AllExceptIdBaud => 0x02,
};
Ok(1)
}
Clear if buffer.len() >= 5 => {
buffer[..6].copy_from_slice(&[0x01, 0x44, 0x58, 0x4C, 0x22]);
Ok(5)
}
ControlTableBackup(direction) if buffer.len() >= 5 => {
buffer[0] = match direction {
BackupDirection::Store => 0x01,
BackupDirection::Restore => 0x02,
};
buffer[1..6].copy_from_slice(&[0x43, 0x54, 0x52, 0x4C]);
Ok(5)
}
SyncRead { addr, len, ids } | FastSyncRead { addr, len, ids }
if buffer.len() >= 4 + ids.len() =>
{
buffer[..2].copy_from_slice(&addr.to_le_bytes());
buffer[2..4].copy_from_slice(&len.to_le_bytes());
buffer[4..4 + ids.len()].copy_from_slice(ids);
Ok(4 + u16::try_from(ids.len()).map_err(|_| Error::Unknown)?)
}
SyncWrite {
addr: _,
len: _,
data: _,
} => unimplemented!(),
BulkRead { data: _ } => unimplemented!(),
BulkWrite { data: _ } => unimplemented!(),
FastBulkRead { data: _ } => unimplemented!(),
_ => Err(Error::BufferSize),
}
}
}

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src/lib.rs Normal file
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#![no_std]
pub mod error;
pub mod instruction;