Bottom LED — Python Example

Source: rbq_sdk/python/example/sport/rbq_led_bottom.py

Python port of the C++ Bottom LED. Sets the two status LEDs under the body by publishing one LedBottom_ message on rt/rbq/cmd/led_bottom, then prints the 1 Hz LedBottomState_ the robot reports on rt/rbq/led_bottom.

How it works

1. Reads interface and optional side mode r g b on_ms off_ms count from the command line.
2. Calls ChannelFactoryInitialize(0, interface), then creates ChannelPublisher("rt/rbq/cmd/led_bottom", LedBottom_) and ChannelSubscriber("rt/rbq/led_bottom", LedBottomState_) with a handler that keeps the latest state.
3. Waits ~0.5 s for DDS discovery, fills the LedBottom_ message and publishes once.
4. Waits ~2.5 s for the IF board to apply the setting and report it, prints the last LedBottomState_ received and exits.

The on-robot Network process checks the ranges (the same check as PUT /api/led/bottom), Motion sends the setting to the IF board over CAN FD, and the board's once-a-second report comes back on rt/rbq/led_bottom.

Prerequisites

• rbq_sdk_py importable — see Python SDK Overview.
• The robot stack running on the same DDS interface.
• A CAN FD robot. On other robots Network rejects the command and publishes no state, so the example prints no state on rt/rbq/led_bottom. In the simulator Motion stands in for the IF board and MuJoCo shows the two LEDs under the body, so the example works there too.

Run

cd RBQ/rbq_sdk/python/example/sport
python3 rbq_led_bottom.py [networkInterface] [side] [mode] [r] [g] [b] [on_ms] [off_ms] [count]

# Both LEDs steady blue (the defaults) — the interface always comes first:
python3 rbq_led_bottom.py eth0

# Right LED blinking red, 0.5 s on / 0.5 s off, forever:
python3 rbq_led_bottom.py eth0 right blink 255 0 0 500 500 0

# Both LEDs off:
python3 rbq_led_bottom.py eth0 both off

All arguments are positional, so the interface must be the first argument.

Arguments and defaults are identical to the C++ version. Use the interface that reaches the robot — lo when running on the robot PC, your NIC from another host.

Example output

[rbq_led_bottom] published: side=right mode=blink rgb=255,0,0 on_ms=500 off_ms=500 count=0
[rbq_led_bottom] state: age_ms=312 configured=1 if_fw=2026100701
  right: mode=blink rgb=255,0,0 on_ms=500 off_ms=500 count=0 actual=255,0,0 lpf_w=0.6
  left: mode=on rgb=0,0,255 on_ms=0 off_ms=0 count=0 actual=0,0,255 lpf_w=0.4

Values depend on the robot. actual is the last output after the IF board's power limit, and limited appears when that limit reduced the output within the last second.