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Command Reference

The library encodes commands; it does not transmit them. Each oscp_cmd_* function writes an ASCII command into a caller-owned buffer, framed for the selected transport, and returns the number of bytes written. The caller transmits those bytes.

let mut cmd = [0u8; 32];

if let Ok(len) = oscp_cmd_config(&mut cmd, OscpTransport::Rs422) {
    /* Transmit as-is */
    platform_dependant_rs422_write(&cmd[..len]);
    /* Delay between consecutive commands */
    platform_dependant_delay_ms(10);
}

let mut cmd = [0u8; 32];

if let Ok(len) = oscp_cmd_config(&mut cmd, OscpTransport::Canfd) {
    /* CAN command ID 0x6FC; caller applies DLC padding */
    platform_dependant_canfd_write(0x6FC, &cmd[..len]);
    /* Delay between consecutive commands */
    platform_dependant_delay_ms(10);
}

Buffer sizing

A 32-byte buffer holds any encoded command. If the buffer is too small, the function returns Err(OscpErr::Err).

How framing depends on transport

The last argument of every command function is an OscpTransport:

Transport Encoding
OscpTransport::Rs422 ASCII payload, COBS-encoded, terminated by 0x00. Transmit unchanged.
OscpTransport::Canfd ASCII payload only; no COBS, no delimiter. The caller sets the CAN command identifier (0x6FC) and the DLC.

Command classes

Commands differ in which state accepts them and in whether the unit replies.

Receiving replies

On RS422, replies are returned by the parser as OscpFrame::CmdResponse(OscpFrameCmd). On CAN-FD, replies use CAN ID 0x6FD. oscp_frame_decode does not decode replies; filter ID 0x6FD before calling it.

Class Reply Valid state
Silent / ANY None Any
Silent / CONFIG None CONFIG
Ack / OPERATING OscpFrameCmd OPERATING
Ack / CONFIG OscpFrameCmd CONFIG
Frame reply / CONFIG Requested frame CONFIG

Frame reply commands

SUF and OF<x> are not acknowledged with OscpFrameCmd::Success. The reply is the requested frame: one OscpFrame::Startup for SUF, one frame of the selected type for OF<x>. OscpFrameCmd::Failed is sent only for an invalid selector, which OscpFrameSel cannot express. OF does not change the periodic output frames; use oscp_cmd_enable_oft / oscp_cmd_disable_oft.

Command catalogue

All functions have the form fn oscp_cmd_X(cmd: &mut [u8], [args,] transport: OscpTransport) -> Result<usize, OscpErr>. The Wire column is the ASCII payload before transport framing.

Silent - valid in ANY state
Function Wire Purpose
oscp_cmd_reset RESET Reset the unit
Silent - valid in CONFIG state
Function Wire Purpose
oscp_cmd_exit EXIT Return from CONFIG to OPERATING state
oscp_cmd_refs REFS Restore factory settings and reset the unit. Replies Failed if the restore fails.
Ack - valid in OPERATING state
Function Wire Purpose
oscp_cmd_config CONFIG Enter CONFIG state
Frame reply - valid in CONFIG state
Function Args Wire Purpose
oscp_cmd_suf - SUF Request one Startup frame
oscp_cmd_of OscpFrameSel OF<x> Request one frame of type x
Ack - valid in CONFIG state
Function Args Wire Purpose
oscp_cmd_om OscpOmSel OM<x> Set operating mode
oscp_cmd_enable_oft OscpFrameSel EOFT<x> Enable an output frame type
oscp_cmd_disable_oft OscpFrameSel DOFT<x> Disable an output frame type
oscp_cmd_drg OscpGyroDr DRG<nnnn> Set gyroscope dynamic range
oscp_cmd_dra OscpAccelDr DRA<nn> Set accelerometer dynamic range
oscp_cmd_dri OscpInclDr DRI<n.n> Set inclinometer dynamic range
oscp_cmd_enable_mcorr - EMCORR Enable misalignment correction
oscp_cmd_disable_mcorr - DMCORR Disable misalignment correction
oscp_cmd_wr OscpUsrReg, u32 WR<REG><8·hex> Write a user register
oscp_cmd_save - SAVE Save configuration to flash

Argument enumerations

Frame selector - OscpFrameSel

Used by oscp_cmd_of, oscp_cmd_enable_oft and oscp_cmd_disable_oft.

Enum Wire char Frame
OscpFrameSel::Raw R Raw
OscpFrameSel::Euler E Euler
OscpFrameSel::Quaternion Q Quaternion
OscpFrameSel::RotMatrix M Rotation matrix
OscpFrameSel::Gnss G GNSS
OscpFrameSel::Debug D Debug 1 and Debug 2; oscp_cmd_of only

OscpFrameSel::Debug with enable/disable

oscp_cmd_enable_oft and oscp_cmd_disable_oft return Err(OscpErr::ErrInvalid) for OscpFrameSel::Debug. Debug frames are not periodic; they are requested with oscp_cmd_of in CONFIG state.

Operating mode - OscpOmSel

Used by oscp_cmd_om.

Enum Wire char RAW ODR GNSS ODR Other frames ODR
OscpOmSel::Idle I 0 Hz 0 Hz 0 Hz
OscpOmSel::Low L 100 Hz 1 Hz 100 Hz
OscpOmSel::Medium M 500 Hz 1 Hz 100 Hz

Gyroscope dynamic range - OscpGyroDr

Used by oscp_cmd_drg.

Enum Range
OscpGyroDr::Dps125 ±125 °/s
OscpGyroDr::Dps250 ±250 °/s
OscpGyroDr::Dps500 ±500 °/s
OscpGyroDr::Dps1000 ±1000 °/s
OscpGyroDr::Dps2000 ±2000 °/s
OscpGyroDr::Dps4000 ±4000 °/s

Accelerometer dynamic range - OscpAccelDr

Used by oscp_cmd_dra.

Enum Range
OscpAccelDr::G2 ±2 g
OscpAccelDr::G4 ±4 g
OscpAccelDr::G8 ±8 g
OscpAccelDr::G16 ±16 g

Inclinometer dynamic range - OscpInclDr

Used by oscp_cmd_dri. Discriminants are in tenths of g.

Enum Range
OscpInclDr::G0_5 ±0.5 g
OscpInclDr::G1_0 ±1.0 g
OscpInclDr::G2_0 ±2.0 g
OscpInclDr::G3_0 ±3.0 g

Readback

The Startup frame reports dynamic ranges with a different encoding. Use from_dyn_range_code; see Reading back dynamic ranges.

User registers - OscpUsrReg

Used by oscp_cmd_wr. The value is encoded as 8 uppercase hexadecimal digits.

Register mnemonics
Group Mnemonics
Gyroscope bias GXB, GYB, GZB, GOB (GOB: optical gyroscope, optical-based models only)
Accelerometer bias AXB, AYB, AZB
Inclinometer bias IXB, IYB
Magnetometer bias MXB, MYB, MZB
Magnetometer calibration matrix MXX…MZZ (9 entries)
AHRS fusion FCO (convention), FHS (heading source), FRT (recovery period), FGA (gain), FAR (accel rejection), FMR (mag rejection)
Gyroscope filters GFI (enable bitmask), GLP (low-pass), GHP (high-pass)
Accelerometer filters AFI (enable bitmask), ALP (low-pass), AHP (high-pass)

Variant names are the mnemonic in title case, e.g. OscpUsrReg::Fga.

/* Write AHRS fusion gain register */
oscp_cmd_wr(&mut cmd, OscpUsrReg::Fga, 0x3F80_0000, OscpTransport::Rs422)?;

Typical configuration sequence

  1. oscp_cmd_config: enter CONFIG from OPERATING. Periodic output stops.
  2. oscp_cmd_om, oscp_cmd_drg, oscp_cmd_dra, oscp_cmd_enable_oft, …: apply settings.
  3. oscp_cmd_exit: return to OPERATING. Periodic output resumes.

See Sending commands for the corresponding code.

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