Centrifuges#

PyLabRobot supports the following centrifuges:

VSpin

Centrifuges are controlled by the Centrifuge class. This class takes a backend as an argument. The backend is responsible for communicating with the centrifuge and is specific to the hardware being used.

from pylabrobot.centrifuge import Centrifuge
backend = SomeCentrifugeBackend()
pr = Centrifuge(backend=backend)
await pr.setup()

The setup() method is used to initialize the centrifuge. This is where the backend will connect to the centrifuge and perform any necessary initialization.

The Centrifuge class has a number of methods for controlling the centrifuge. These are:

open_door(): Open the centrifuge door.
close_door(): Close the centrifuge door.
lock_door(): Lock the centrifuge door.
unlock_door(): Unlock the centrifuge door.
lock_bucket(): Lock centrifuge buckets.
unlock_bucket(): Unlock centrifuge buckets.
go_to_bucket1(): Rotate to Bucket 1.
go_to_bucket2(): Rotate to Bucket 2.
rotate_distance(): Rotate the buckets a specified distance (8000 = 360 degrees).
start_spin_cycle(): Start centrifuge spin cycle.

Start spin cycle:

await cf.start_spin_cycle(g = 800, duration = 60)

VSpin#

The VSpin centrifuge is controlled by the VSpin class.

from pylabrobot.centrifuge import Centrifuge, VSpin
cf = Centrifuge(name = 'centrifuge', backend = VSpin(bucket_1_position=0), size_x= 1, size_y=1, size_z=1)

Installation#

The VSpin centrifuge connects to your system via a COM port. Integrating it with pylabrobot library requires some setup. Follow this guide to get started.

1. Preparing Your Environment#

Windows:

Find Your Python Directory#

To use the necessary FTDI .dll files, you need to locate your Python environment:

Open Python in your terminal:

python
>>> import sys
>>> sys.executable

This will print a path, e.g., C:\Python39\python.exe.
Navigate to the Scripts folder in the same directory as python.exe.

Download FTDI DLLs#

Download the required .dll files from the following link: FTDI Development Kit (link will start download).

Extract the downloaded zip file.
Locate the bin64 folder.
Copy the files named:
- libftdi1.dll
- libusb-1.0.dll

Place DLLs in Python Scripts Folder#

Paste the copied .dll files into the Scripts folder of your Python environment. This enables Python to communicate with FTDI devices.

macOS:

Install libftdi using Homebrew:

brew install libftdi

Linux:

Debian (rpi) / Ubuntu etc:

sudo apt-get install libftdi-dev

Other distros may have similar packages.

2. Configuring the Driver with Zadig#

This step is only required on Windows.

Use Zadig to replace the default driver of the VSpin device with libusbk:

Identify the VSpin Device
- Open Zadig.
- To confirm the VSpin device, disconnect the RS232 port from the centrifuge while monitoring the Zadig device list.
- The device that disappears is your VSpin, likely titled “USB Serial Converter.”
Replace the Driver
- Select the identified VSpin device in Zadig.
- Replace its driver with libusbk.
- Optionally, rename the device to “VSpin” for easy identification.

Note: If you need to revert to the original driver for tools like the Agilent Centrifuge Config Tool, go to Device Manager and uninstall the libusbk driver. The default driver will reinstall automatically.

3. Finding the FTDI ID#

To interact with the centrifuge programmatically, you need its FTDI device ID. Use the following steps to find it:

Open a terminal and run:

python -m pylibftdi.examples.list_devices

This will output something like:
```
FTDI:USB Serial Converter:FTE0RJ5T
```
Copy the ID (FTE0RJ5T or your equivalent).

4. Setting Up the Centrifuge#

Use the following code to configure the centrifuge in Python:

from pylabrobot.centrifuge import Centrifuge, VSpin

# Replace with your specific FTDI device ID and bucket position for profile in Agilent Centrifuge Config Tool.
backend = VSpin(bucket_1_position=6969, device_id="XXXXXXXX")
centrifuge = Centrifuge(
   backend=backend,
   name="centrifuge",
   size_x=1, size_y=1, size_z=1
)

# Initialize the centrifuge.
await centrifuge.setup()

You’re now ready to use your VSpin centrifuge with pylabrobot!