Hardware calibrations

Hardware calibrations serve as a method to get accurate performance from your Pioreactor.

Stirring calibrations

tip

This is optional, but can really help stirring performance. Creating a stirring calibration is also very easy, so we recommend it.

1. Start by filling a Pioreactor vial about 3/4th with water, and place the stirbar inside. Close with lid. Place into the Pioreactor.
2. We'll perform this routine through your computer's command line. Need help accessing it?
3. Enter ssh pioreactor@<insert unit name>.local.
   • For example, to calibrate on our Pioreactor named worker3, we typed ssh pioreactor@worker3.local.
   • The default password is raspberry.
4. After SSHing into your Pioreactor, enter pio calibrations run --device stirring.
5. The Pioreactor will increment the voltage applied to the motor, and record the RPM. After it's done, it will collect this data into a calibration curve, and store it locally.
6. At the end, you'll be prompted to set this as the "active" calibration. Select "Yes".

You're done! Your stirring RPM should be much more responsive now.

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Pump calibration

Calibrating a pump, like a low-volume peristaltic pump, is very important to accurately dispense or remove a target volume. There is no liquid feedback loop in the Pioreactor (unlike in the stirring & RPM relationship), so this calibration curve is important.

There are three pumps on the Pioreactor: media, alt-media, and waste. You don't need to have all three available, and can calibrate them one at a time. For calibration, you'll need the following:

1. A pump, with power connection to Pioreactor's PWM outputs
2. An accurate weighing scale, with accuracy of 0.1g or better.
3. Container of water

tip

Supplying external power? Make sure to plug in your external power before pump calibration!

Calibrating the pumps #

1. We'll perform this routine through your computer's command line. Need help accessing it?
2. Enter ssh pioreactor@<insert unit name>.local.
   • For example, to calibrate on our Pioreactor named worker3, we typed ssh pioreactor@worker3.local.
   • The default password is raspberry.
3. To calibrate the media_pump, enter pio calibrations run --device media_pump. Likewise for waste_pump and alt_media_pump.
4. Follow the prompts to calibrate your pump.
5. At the end, you'll be prompted to set this as the "active" calibration. Select "Yes".

Managing calibrations

From both the UI and the command line, you can manage your Pioreactor's calibrations.

In the UI

• Use the Pioreactor and Device filters at the top of the Calibrations page to focus on a specific unit and hardware type. Toggle Only Active calibrations to hide everything except the curve currently in use.
• Click any calibration row to open its detail view. Use Set active to mark that calibration as the one the Pioreactor will use for that device (only one calibration can be active per device per Pioreactor). Use Set inactive to clear it and disable calibration for that device.
• The chart in both the list view and detail view has a download icon—click it to export a PNG of the calibration curve for lab notes. The top-level Download all calibrations button grabs all calibration YAML files for backup.
• To edit a calibration, open its detail view and choose View YAML. Make small changes, save the YAML, and re-upload it via Upload calibration (or edit the YAML on-disk and use pio calibrations display to confirm before setting it active).

From the command line

• List what you have with pio calibrations list or scope to a single device with pio calibrations list --device <device>.
• Set which calibration is active with pio calibrations set-active --device <device> --name <calibration_name>. Omit --name to clear the active calibration for that device.