C++ Binding Overview - MotorBridge Python SDK

Channel Compatibility (PCAN + slcan + CAN-FD + Damiao Serial Bridge)

Linux SocketCAN uses interface names directly: can0, can1, slcan0.
For USB-serial CAN adapters, bring up slcan0 first: sudo slcand -o -c -s8 /dev/ttyUSB0 slcan0 && sudo ip link set slcan0 up.
CAN-FD transport is available both in CLI (--transport socketcanfd) and C++ SDK (Controller::from_socketcanfd(...)), and is required for Hexfellow.
Damiao-only serial bridge transport is also available in CLI (--transport dm-serial --serial-port /dev/ttyACM0 --serial-baud 921600).
Full Damiao serial-bridge interface list and command patterns are documented in motor_cli/README.md (section 3.6 in motor_cli/README.zh-CN.md).
On Linux SocketCAN, do not append bitrate in --channel (for example can0@1000000 is invalid).
On Windows (PCAN backend), can0/can1 map to PCAN_USBBUS1/2; optional @bitrate suffix is supported.

RAII-style C++ wrapper on top of motor_abi.

Chinese version: README.zh-CN.md

ABI Metadata Helpers

motorbridge::abi_version() returns the loaded ABI library version.
motorbridge::abi_capabilities_json() returns the loaded ABI capability JSON.
Binding parity is tracked in bindings/api_surface.json.

Damiao Set-Zero Rule (dm-serial)

For Damiao, call disable() before set_zero_position().
Core guard rejects set_zero_position() when motor is not disabled.
Core applies an internal fixed settle (~20ms) after set_zero_position().
C++/ABI signatures are unchanged; this is behavior guard in core.

Controller Entrypoints

Controller(channel) (SocketCAN/PCAN path)
Controller::from_socketcanfd(channel) (CAN-FD path, required by Hexfellow)
Controller::from_dm_serial(serial_port, baud) (Damiao-only serial bridge)
add_damiao_motor(motor_id, feedback_id, model)
add_hexfellow_motor(motor_id, feedback_id, model)
add_myactuator_motor(motor_id, feedback_id, model)
add_robstride_motor(motor_id, feedback_id, model)
add_hightorque_motor(motor_id, feedback_id, model)

Quick Start

Damiao:

#include "motorbridge/motorbridge.hpp"

int main() {
  motorbridge::Controller ctrl("can0");
  auto motor = ctrl.add_damiao_motor(0x01, 0x11, "4340P");
  ctrl.enable_all();
  motor.ensure_mode(motorbridge::Mode::MIT, 1000);
  motor.send_mit(0.0f, 0.0f, 20.0f, 1.0f, 0.0f);
  ctrl.shutdown();
  return 0;
}

Damiao over serial bridge:

#include "motorbridge/motorbridge.hpp"

int main() {
  auto ctrl = motorbridge::Controller::from_dm_serial("/dev/ttyACM1", 921600);
  auto motor = ctrl.add_damiao_motor(0x04, 0x14, "4310");
  ctrl.enable_all();
  motor.send_mit(0.5f, 0.0f, 20.0f, 1.0f, 0.0f);
  ctrl.shutdown();
  return 0;
}

RobStride:

#include "motorbridge/motorbridge.hpp"

int main() {
  motorbridge::Controller ctrl("can0");
  auto motor = ctrl.add_robstride_motor(127, 0xFD, "rs-06"); // replace with the RS model you use for limits/logging
  auto ids = motor.robstride_ping();
  float pos = motor.robstride_get_param_f32(0x7019);
  ctrl.shutdown();
  return static_cast<int>(ids.first == 127 && pos > -1000.0f);
}

RobStride supports rs-00 through rs-06. The C++ wrapper keeps one add_robstride_motor(...) shape, but parameter read/write is backed by the common section 4 runtime table. RobStride-specific wrapper helpers include:

robstride_ping()
robstride_ping_host_id(host_id, timeout_ms)
robstride_get_param_f32_host_id(param_id, host_id, timeout_ms)
robstride_get_fault_report()
robstride_set_device_id(new_device_id)
robstride_set_active_report(enabled)
robstride_get_param_i8/u8/u16/u32/f32(param_id, timeout_ms)
robstride_write_param_i8/u8/u16/u32/f32(param_id, value)

MyActuator:

#include "motorbridge/motorbridge.hpp"

int main() {
  motorbridge::Controller ctrl("can0");
  auto motor = ctrl.add_myactuator_motor(1, 0x241, "X8");
  ctrl.enable_all();
  motor.ensure_mode(motorbridge::Mode::POS_VEL, 1000);
  motor.send_pos_vel(3.1416f, 2.0f);  // rad / rad/s
  ctrl.shutdown();
  return 0;
}

Hexfellow (CAN-FD only):

#include "motorbridge/motorbridge.hpp"

int main() {
  auto ctrl = motorbridge::Controller::from_socketcanfd("can0");
  auto motor = ctrl.add_hexfellow_motor(0x01, 0x00, "hexfellow");
  ctrl.enable_all();
  motor.ensure_mode(motorbridge::Mode::MIT, 1000);  // Hexfellow: MIT / POS_VEL only
  motor.send_mit(0.8f, 1.0f, 30.0f, 1.0f, 0.1f);
  ctrl.shutdown();
  return 0;
}

Example Programs

examples/cpp_wrapper_demo.cpp
examples/hexfellow_canfd_demo.cpp (Hexfellow, CAN-FD, MIT / POS_VEL only)
examples/robstride_wrapper_demo.cpp
examples/full_modes_demo.cpp
examples/pid_register_tune_demo.cpp
examples/scan_ids_demo.cpp (Damiao legacy helper)
examples/pos_ctrl_demo.cpp
examples/pos_repl_demo.cpp

Unified scan via Rust CLI:

cargo run -p motor_cli --release -- \
  --vendor all --channel can0 --mode scan --start-id 1 --end-id 255

HighTorque via Rust CLI:

cargo run -p motor_cli --release -- \
  --vendor hightorque --channel can0 --motor-id 1 --mode read

HighTorque via C++ binding:

#include "motorbridge/motorbridge.hpp"

int main() {
  motorbridge::Controller ctrl("can0");
  auto motor = ctrl.add_hightorque_motor(1, 0x01, "hightorque");
  motor.send_mit(3.1416f, 0.8f, 0.0f, 0.0f, 0.8f);  // kp/kd kept for signature compatibility
  motor.request_feedback();
  auto st = motor.get_state();
  ctrl.shutdown();
  return st.has_value() ? 0 : 1;
}

Experimental Windows Support (PCAN-USB)

Linux remains the primary target. Windows support is experimental and currently uses PEAK PCAN.

Install PEAK PCAN driver + PCAN-Basic runtime (PCANBasic.dll).
Use can0@1000000 for channel/bitrate in Windows CLI validation.

Validation commands:

cargo run -p motor_cli --release -- --vendor damiao --channel can0@1000000 --model 4340P --motor-id 0x01 --feedback-id 0x11 --mode scan --start-id 1 --end-id 16
cargo run -p motor_cli --release -- --vendor damiao --channel can0@1000000 --model 4340P --motor-id 0x01 --feedback-id 0x11 --mode pos-vel --pos 3.1416 --vlim 2.0 --loop 1 --dt-ms 20
cargo run -p motor_cli --release -- --vendor damiao --channel can0@1000000 --model 4310 --motor-id 0x07 --feedback-id 0x17 --mode pos-vel --pos 3.1416 --vlim 2.0 --loop 1 --dt-ms 20

Build

cargo build -p motor_abi --release
cmake -S bindings/cpp -B bindings/cpp/build \
  -DMOTORBRIDGE_ABI_LIBRARY=$PWD/target/release/libmotor_abi.so
cmake --build bindings/cpp/build -j

End-to-End Demo Commands

export LD_LIBRARY_PATH=$PWD/target/release:${LD_LIBRARY_PATH}

# Damiao wrapper demo
./bindings/cpp/build/cpp_wrapper_demo \
  --channel can0 --model 4340P --motor-id 0x01 --feedback-id 0x11 \
  --pos 0 --vel 0 --kp 20 --kd 1 --tau 0 --loop 20 --dt-ms 20

# RobStride wrapper demo: ping
./bindings/cpp/build/robstride_wrapper_demo \
  --channel can0 --model rs-06 --motor-id 127 --feedback-id 0xFD --mode ping

# RobStride wrapper demo: velocity
./bindings/cpp/build/robstride_wrapper_demo \
  --channel can0 --model rs-06 --motor-id 127 --feedback-id 0xFD \
  --mode vel --vel 0.3 --loop 40 --dt-ms 50

​Channel Compatibility (PCAN + slcan + CAN-FD + Damiao Serial Bridge)

​ABI Metadata Helpers

​Damiao Set-Zero Rule (dm-serial)

​Controller Entrypoints

​Quick Start

​Example Programs

​Experimental Windows Support (PCAN-USB)

​Build

​End-to-End Demo Commands