Package ROHand

Nodes for ROHand. One bus, i.e. one port need one node.

1. Clone

cd ~
mkdir -p ros2_ws/src
cd ros2_ws/src
git clone ssh://[email protected]/oymotion/rohand_ros2_pkg

2. Prepare

Install pymodbus

cd /path/to/workspace  # Should be ~/ros2_ws/src

# Create a vertual env for python
virtualenv -p python3 ./venv

# Make sure that colcon doesn’t try to build the venv
touch ./venv/COLCON_IGNORE

# Activate
source ./venv/bin/activate

# Install python module
python3 -m pip install pymodbus

Edit ~/bashrc and add virtual env lib path to PYTHONPATH

export PYTHONPATH=$PYTHONPATH:~/ros2_ws/src/venv/lib/python3.12/site-packages  # Modify python3.12 to your actual versioni
source ~/.bashrc

3. Compile

cd /path/to/workspace
colcon build

4. Node rohand

Listens to topic 'target_joint_state' and controls ROHand, reads current joint state and publish to 'current_joint_state'.

4.1 Topics

Topic	Description
"current_joint_state"	current joint state in message type JointState, frame_id in header distinguishes hand id
"target_joint_state"	target joint state in message type JointState, frame_id in header distinguishes hand id

4.2 Run

# Prepare package
source /path/to/workspace/install/bash

# Insert USB-485 module to USB port then add permission to users
# Run following command every time you plug in your USB-485 module
sudo chmod o+rw /dev/ttyUSB0  # Modify ttyUSB0 to your actual device name

# Run node
ros2 run rohand rohand --ros-args -p port_name:="/dev/ttyUSB0" -p baudrate:=115200 -p hand_ids:=[2,3]  # Modify parameters according to your real case

5. Node rohand_teleop

Reads keys to modify target joint angles, then publish to 'target_joint_state'.

5.1 Topics

Topic	Description
"target_joint_state"	target joint state in message type JointState, frame_id in header distinguishes hand id

5.2 Run

# Prepare package
source /path/to/workspace/install/bash

# Run node
ros2 run rohand rohand_teleop --ros-args -r rohand_teleop_node/target_joint_states:=/rohand_node/target_joint_states -p hand_id:=2  # Modify parameters according to your real case

Press following keys to operate:

key	Description
q	quit
a	thumb bends by step
z	thumb relaxes by step
s	index bends by step
x	index relaxes by step
d	middle bends by step
c	middle relaxes by step
f	ring bends by step
v	ring relaxes by step
g	little bends by step
b	little relaxes by step
h	thumb rotation +step
n	thumb rotation -step

Step is range / 10.