Add additional methods for low level single motor control (#22)

This PR adds the ability to refresh and query specific motors. The
current use case is primarily for calibration.

.gitignore

@@ -0,0 +1,16 @@
+# Copyright 2025 Enactic, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+/.vscode
+/build

include/openarm/can/socket/arm_component.hpp

@@ -27,9 +27,9 @@ public:
     ArmComponent(canbus::CANSocket& can_socket);
     ~ArmComponent() = default;
 
-    void init_motor_devices(std::vector<damiao_motor::MotorType> motor_types,
-                            std::vector<uint32_t> send_can_ids, std::vector<uint32_t> recv_can_ids,
-                            bool use_fd);
+    void init_motor_devices(const std::vector<damiao_motor::MotorType>& motor_types,
+                            const std::vector<uint32_t>& send_can_ids,
+                            const std::vector<uint32_t>& recv_can_ids, bool use_fd);
 
 private:
     std::vector<damiao_motor::Motor> motors_;

include/openarm/can/socket/openarm.hpp

@@ -48,6 +48,8 @@ public:
     void disable_all();
     void set_zero_all();
     void refresh_all();
+
+    void refresh_one(int i);
     // The timeout for reading from socket, set to timeout_us.
     // Tuning this value may improve the performance but should be done with caution.
     void recv_all(int timeout_us = 500);

include/openarm/damiao_motor/dm_motor_device_collection.hpp

@@ -32,9 +32,12 @@ public:
     // Common motor operations
     void enable_all();
     void disable_all();
-    void set_zero_all();
     void set_callback_mode_all(CallbackMode callback_mode);
 
+    // Flash new zero position
+    void set_zero(int i);
+    void set_zero_all();
+
     // Refresh operations (for individual motors)
     void refresh_one(int i);
     void refresh_all();
@@ -49,6 +52,7 @@ public:
 
     // Device collection access
     std::vector<Motor> get_motors() const;
+    Motor get_motor(int i) const;
     canbus::CANDeviceCollection& get_device_collection() { return *device_collection_; }
 
 protected:

src/openarm/can/socket/arm_component.cpp

@@ -23,9 +23,9 @@ namespace openarm::can::socket {
 ArmComponent::ArmComponent(canbus::CANSocket& can_socket)
     : damiao_motor::DMDeviceCollection(can_socket) {}
 
-void ArmComponent::init_motor_devices(std::vector<damiao_motor::MotorType> motor_types,
-                                      std::vector<canid_t> send_can_ids,
-                                      std::vector<canid_t> recv_can_ids, bool use_fd) {
+void ArmComponent::init_motor_devices(const std::vector<damiao_motor::MotorType>& motor_types,
+                                      const std::vector<canid_t>& send_can_ids,
+                                      const std::vector<canid_t>& recv_can_ids, bool use_fd) {
     // Reserve space to prevent vector reallocation that would invalidate motor
     // references
     motors_.reserve(motor_types.size());

src/openarm/can/socket/openarm.cpp

@@ -73,6 +73,12 @@ void OpenArm::refresh_all() {
     }
 }
 
+void OpenArm::refresh_one(int i) {
+    for (damiao_motor::DMDeviceCollection* device_collection : sub_dm_device_collections_) {
+        device_collection->refresh_one(i);
+    }
+}
+
 void OpenArm::disable_all() {
     for (damiao_motor::DMDeviceCollection* device_collection : sub_dm_device_collections_) {
         device_collection->disable_all();

src/openarm/damiao_motor/dm_motor_device_collection.cpp

@@ -41,6 +41,12 @@ void DMDeviceCollection::disable_all() {
     }
 }
 
+void DMDeviceCollection::set_zero(int i) {
+    auto dm_device = get_dm_devices().at(i);
+    auto zero_packet = CanPacketEncoder::create_set_zero_command(dm_device->get_motor());
+    send_command_to_device(dm_device, zero_packet);
+}
+
 void DMDeviceCollection::set_zero_all() {
     for (auto dm_device : get_dm_devices()) {
         CANPacket zero_packet = CanPacketEncoder::create_set_zero_command(dm_device->get_motor());
@@ -114,6 +120,8 @@ std::vector<Motor> DMDeviceCollection::get_motors() const {
     return motors;
 }
 
+Motor DMDeviceCollection::get_motor(int i) const { return get_dm_devices().at(i)->get_motor(); }
+
 std::vector<std::shared_ptr<DMCANDevice>> DMDeviceCollection::get_dm_devices() const {
     std::vector<std::shared_ptr<DMCANDevice>> dm_devices;
     for (const auto& [id, device] : device_collection_->get_devices()) {