diff --git a/.gitignore b/.gitignore index 3ca43ae..193d30e 100644 --- a/.gitignore +++ b/.gitignore @@ -14,3 +14,8 @@ Cargo.lock # MSVC Windows builds of rustc generate these, which store debugging information *.pdb + + +# Added by cargo + +/target diff --git a/Cargo.toml b/Cargo.toml new file mode 100644 index 0000000..28b8de2 --- /dev/null +++ b/Cargo.toml @@ -0,0 +1,14 @@ +[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] diff --git a/src/error.rs b/src/error.rs new file mode 100644 index 0000000..3fb08e7 --- /dev/null +++ b/src/error.rs @@ -0,0 +1,42 @@ +#[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 + } + } +} diff --git a/src/instruction.rs b/src/instruction.rs new file mode 100644 index 0000000..eaffe20 --- /dev/null +++ b/src/instruction.rs @@ -0,0 +1,206 @@ +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 { + 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), + } + } +} diff --git a/src/lib.rs b/src/lib.rs new file mode 100644 index 0000000..1125d3a --- /dev/null +++ b/src/lib.rs @@ -0,0 +1,4 @@ +#![no_std] + +pub mod error; +pub mod instruction;