Description

ROS 2 package for receiving CRSF (RC channels values) packets over serial port (UART).

CRSF protocol packet format description.

Topics

• rc/channels - received rc channels values
• rc/link - connection statistics information

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Installation

Dependencies:

Install CppLinuxSerial before:

git clone https://github.com/gbmhunter/CppLinuxSerial.git

cd CppLinuxSerial
mkdir build/
cd build
cmake ..
make
sudo make install
cd ../..

Let's assume that your ros 2 workspace localized at ~/row2_ws/.

1. Clone package from git:

cd ~/row2_ws/src

# Types dependency package:
git clone https://github.com/AndreyTulyakov/ros2_crsf_receiver.git

2. Build

cd ~/row2_ws

colcon build --packages-select crsf_receiver_msg
colcon build --packages-select crsf_receiver

3. Re-source

source ~/row2_ws/install/setup.bash

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Running

Set up params:

1. Serial device name: device, default is /dev/ttyUSB0
2. Baud rate: baud_rate, default is 420000
3. Enable / Disable link statistics info: link_stats, default is false
4. Receiver rate (hz): receiver_rate, default is 100

Run ros node:

# Run Node with default parameters
ros2 run crsf_receiver crsf_receiver_node

# Or setup and run Node with custom parameters values:
ros2 run crsf_receiver crsf_receiver_node --ros-args -p "device:=/dev/serial0" -p baud_rate:=420000  -p link_stats:=true

Check

After correct setup and running without errors you can check topics:

# Check channels values
ros2 topic echo /rc/channels

# Check link statisics
ros2 topic echo /rc/link

# Check receiver rate
ros2 topic hz /rc/channels

Link statistics message fields:

• uplink_rssi_ant1 - ( dBm * -1 )
• uplink_rssi_ant2 - ( dBm * -1 )
• uplink_status - Package success rate / Link quality ( % )
• uplink_snr - ( db )
• active_antenna - Diversity active antenna ( enum ant. 1 = 0, ant. 2 )
• rf_mode - ( enum 4fps = 0 , 50fps, 150hz)
• uplink_tx_power - ( enum 0mW = 0, 10mW, 25 mW, 100 mW, 500 mW, 1000 mW, 2000mW )
• downlink_rssi - ( dBm * -1 )
• downlink_status - Downlink package success rate / Link quality ( % )
• downlink_snr - ( db )