basic_bot.commons.constants

basic_bot.commons.constants can be imported to access the constants used by basic_bot services. The constants are set by default and all can be overridden by setting environment variables.

If you are using bb_start to start the services, you can set the BB_ environment variables in the basic_bot.yml file. See the bb_start documentation

BB_ENV

Test runner will set this to "test".

Set this to "production" on the onboard computer to run the bot in production mode. See Getting Started Guide for more information.

BB_LOG_ALL_MESSAGES

Set this to True to log all messages sent and received by services to each of their respective log files.

BB_LOG_DEBUG

Set this to True to write all log.debug to the log file. Note that log.debug calls are also written to the log file when BB_ENV is "development" or "test".

BB_HUB_HOST

The websocket host that the central hub is running.

BB_HUB_PORT

The websocket port that the central_hub service listens on.

BB_HUB_URI

This is the full URI to connect to the central_hub service websocket.

BB_MOTOR_I2C_ADDRESS

Used by basic_bot.services.motor_control_2w to connect to the i2c motor controller.

BB_LEFT_MOTOR_CHANNEL

default: 1

BB_RIGHT_MOTOR_CHANNEL

default: 2

BB_SERVO_CONFIG_FILE

See api docs for servo control services

BB_SYSTEM_STATS_SAMPLE_INTERVAL

In seconds, the interval at which the system stats service samples the system and publishes system stats to the central hub.

BB_CAMERA_MODULE

default: "basic_bot.commons.camera_opencv" or "basic_bot.test_helpers.camera_mock" when BB_ENV=test

When using a ribbon cable camera on a Raspberry Pi 4/5, set this to "basic_bot.commons.camera_picamera".

BB_CAMERA_CHANNEL

The camera channel to use. 0 is the default camera.

BB_CAMERA_ROTATION

The camera rotation in degrees. 0 is the default rotation.

BB_CAMERA_FPS

The camera setting frames per second.

BB_VISION_WIDTH

In pixels, this is the width of the camera frame to capture.

BB_VISION_HEIGHT

In pixels, this is the height of the camera frame to capture.

BB_VISION_FOV

The field of view of the camera in degrees. Depends on camera; RPi v2 cam is 62 deg.

BB_OBJECT_DETECTION_THRESHOLD

The object detection threshold percentage 0 - 1; higher = greater confidence.

BB_ENABLE_CORAL_TPU

Set this to True to enable the Coral USB TPU for object detection.

BB_TFLITE_MODEL

Which model to use for object detection when BB_ENABLE_CORAL_TPU is false. Default is the model from the coral site which is faster than the model from the tensorflow hub

BB_TFLITE_MODEL_CORAL

Which model to use for object detection when BB_ENABLE_CORAL_TPU is true.

BB_TFLITE_THREADS

Number of threads to use for tflite detection. Testing object detection on a Rasberry PI 5, without any other CPU or memory pressure, 4 tflite threads was only 1 fps faster (29.5fps) than 3 threads (28.6fps). 2 threads was 22fps.

Warning: Setting this too high can actually reduce the object detection frame rate. In the case of daphbot_due, which has a pygame based onboard UI service that has a configurable render frame rate, the tflite detection running on 4 threads was reduced to about 12 fps when the render frame rate was set to 30fps.

BB_VISION_HOST

The IP address that the vision service is running on for REST api and video streaming.

BB_VISION_PORT

The HTTP port that the vision service listens on for video streaming and REST api.

BB_MJPEG_VIDEO_PORT

The HTTP port that the vision service listens on for video MJPEG streaming.

BB_VISION_URI

The full URI to connect to the vision service REST and video streaming.

BB_DISABLE_RECOGNITION_PROVIDER

Set this to True to disable the recognition provider.

BB_VIDEO_PATH

The path where the vision service saves recorded video.

BB_LEGACY_RECORD_VIDEO

Set this to True to use the legacy video recording method which buffers frames directly from the camera module instead of using WebRTC.

BB_USE_ARECORD

Set this to True to use arecord for audio capture instead of PulseAudio (Linux only). Provides lower latency audio streaming via direct ALSA access.

BB_AUDIO_BUFFER_SIZE

Buffer size for arecord audio capture. Smaller values reduce latency but may cause audio dropouts. Only used when BB_USE_ARECORD is True.

BB_AUDIO_PERIOD_SIZE

Period size for arecord audio capture. Smaller values reduce latency. Only used when BB_USE_ARECORD is True.

BB_AUDIO_SAMPLE_RATE

Sample rate for arecord audio capture. Lower values reduce processing overhead and latency. 22050 provides good quality with minimal latency. Only used when BB_USE_ARECORD is True.

BB_AUDIO_CHANNELS

Number of audio channels for arecord capture. 1=mono, 2=stereo. Mono reduces processing overhead and latency. Only used when BB_USE_ARECORD is True.

BB_WEB_PUBLIC

The path to the directory containing the web application's static files. The web server will serve files from this directory.