Sphero Bolt Python Library

Hardware shopping list

Sphero Bolts
Realsense D415
Microphone

Compute requirements

This should work on Linux 16.04, 18.04, and 20.04. This was tested on 18.04 and 20.04. The docker image pulls from an 18.04 base image.

Configure bluetooth on host machine

On host OS, run
sudo apt-get install blueman
reboot

Now, open blueman. This should be an option on the top right of the menu bar. For each device SB-XXXX (Sphero Bolts) click "add" and then "proceed without pairing". Once each device is "known" to the your host machine in this way, your computer should remember the Bolts as "friendlies" forever.

Plug in peripherals

Plug the realsense and Q9-1 Microphone into host usb ports. The microphone can use usb2.0, but the realsense needs usb3.0.

Build the docker image

docker build -t spheroimage:1.0 .

Make a dataset directory

mkdir dataset

Run the docker container

docker run --net=host --privileged --mount type=bind,source=/var/run/dbus/system_bus_socket,target=/var/run/dbus/system_bus_socket --mount type=bind,source=/<path_to_lib>/SpheroPyLib/dataset,target=/sphero/dataset -it spheroimage:1.0

Populate the dataset

python3.8 collector_manager.py dataset
This script will add data to the "dataset" folder up to a certain number of samples, specified in "gather_random_dataset_sphero.py"

Sphero Configuration

In SpheroLib/config is the configuration of the envrironment.

sphero_config = {
    "SIMULTANEOUS_SPHEROS": 1,
    "SPHEROMACS": [
        "D1:E3:4B:81:F3:29",
        "DA:E7:C9:C5:81:CD",
        "E1:91:60:4F:3B:27",
        "E1:91:60:4F:3B:27", 
                   ],
    "SPHEROCOLORASSIGNMENTS": [(255, 0, 0),
                               (0, 255, 0),
                               (0, 0, 255),
                               (255, 255, 255)],
    # Amount of time to maintain past state for.
    "STATE_LEN_TIME_SECS": 2,
    ...

The library supports multirobot setups, although the current dataset collection script is just commanding one.

To control 2+ robots, simply add their mac addresses and color assignments to the config and set "SIMULTANEOUS_SPHEROS" to the correct number.

In the data collection script, add a line sphero_lib.set_sphero_action for each sphero num (first arg) that you wish to control

for elt in range(4):
    action_start = time.time()
    sphero_lib.set_sphero_action(0, heading_trajectory[elt], speed_trajectory[elt])
    # sphero_lib.set_sphero_action(1, heading_trajectory[elt], speed_trajectory[elt])
    time.sleep(max([.5 - (time.time() - action_start), 0]))

When a Sphero dies, switch the order of the MAC addresses to use a different one (the library uses the topmost MAC address/s)

Docker Bugs

The library seems to not shutdown correctly from a ctrl + c from docker. Some processes, including the ones controlling the robot, get orphaned. I'm sure this is a trivial fix.

Common Errors:

###"ValueError: No input device matching 'Q9-1'"### The microphone is not being recognized by the computer. Try rebooting and unplugging. On your host machine, you should be able to open a python script and run:
import sounddevice as sd
print (sd.query_devices())

and see an entry for:
X Q9-1: USB Audio (hw:1,0), ALSA (1 in, 0 out)

If not, keep rebooting. Glhf.

Camera not connected

  File "/usr/lib/python3.8/multiprocessing/process.py", line 313, in _bootstrap
    self.run()
  File "/usr/lib/python3.8/multiprocessing/process.py", line 108, in run
    self._target(*self._args, **self._kwargs)
  File "/sphero/SpheroLib/camera.py", line 19, in run_camera
    prof = pipeline.start(cam_config)
RuntimeError: Couldn't resolve requests

To fix this, on your host machine open up the realsense-viewer and ensure that the camera is visible (and that the connection says usb 3.X, not 2.X).

Bluetooth Connectivity Error

Traceback (most recent call last):
  File "/usr/local/lib/python3.8/dist-packages/gatt/gatt_linux.py", line 293, in _connect
    self._object.Connect()
  File "/usr/local/lib/python3.8/dist-packages/dbus/proxies.py", line 72, in __call__
    return self._proxy_method(*args, **keywords)
  File "/usr/local/lib/python3.8/dist-packages/dbus/proxies.py", line 141, in __call__
    return self._connection.call_blocking(self._named_service,
  File "/usr/local/lib/python3.8/dist-packages/dbus/connection.py", line 652, in call_blocking
    reply_message = self.send_message_with_reply_and_block(
dbus.exceptions.DBusException: org.bluez.Error.Failed: Input/output error

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.8/multiprocessing/process.py", line 313, in _bootstrap
    self.run()
  File "/usr/lib/python3.8/multiprocessing/process.py", line 108, in run
    self._target(*self._args, **self._kwargs)
  File "/sphero/SpheroLib/sphero_bluetooth.py", line 22, in run_sphero
    device.connect()
  File "/usr/local/lib/python3.8/dist-packages/gatt/gatt_linux.py", line 288, in connect
    self._connect()
  File "/usr/local/lib/python3.8/dist-packages/gatt/gatt_linux.py", line 312, in _connect
    self.connect_failed(_error_from_dbus_error(e))
  File "/sphero/SpheroLib/sphero_bluetooth.py", line 110, in connect_failed
    self.log("[%s] Connection failed: %s" % (str(error)))
TypeError: not enough arguments for format string

This one is likely either:

• Bluetooth is not on on your host machine.
• You can't see the spheros. Pull up the bluetooth devices on your host machine. Do you see each "SB-XXXX" device?
• You have not opened blueman and added each device. Or you need to try doing that a few more times. I have not been thrilled with the linux bluetooth stack.