Nutrient solution

Follow Pioreactor’s peristaltic pump setup guide, with these channels. Stop before calibrating: that is the next step, once this one’s checks pass.

1. On the unit’s Configuration page, set [PWM] channel 3 to waste, leave 4 as relay, and click Save.

2. Seat the pumps.

3. Plug the media pump into PWMOne of the HAT's five switched power outputs. In this build: 1 stirring, 2 media pump, 3 waste (product) pump, 4 CO₂ solenoid (relay), 5 heating. 2 and the product pump into PWM 3.

4. Lead the cables out through the notches.

5. Put the media and product bottles into their holders, with a 0.2 μm vent filterA 0.2 µm hydrophobic membrane on luer fittings. Gas passes; microbes and liquid do not, so each gas path stays sterile. on each GL45A standard 45 mm screw thread on lab bottles such as Duran. The media and product bottles and their multi-port caps use it. cap’s vent port.

6. Connect each bottle to its pump with the silicone tubing and luerA standard medical screw fitting. A male luer (the spigot) screws into a female luer (the socket). In this build, male ends mark outlets. fittings.

   Note

   The kit’s in-line parts on the media lines are non-return valves, not filters.

7. Check the 12V supply is in the HATThe Pioreactor circuit board that plugs onto the Raspberry Pi's pin header. It carries the PWM and LED outputs and the 12V barrel jack.’s barrel jack (external power). The shuntA small jumper on the HAT. In the position closest to the LED outputs it feeds the 12V supply to PWM channels 1 to 4. was checked in Raspberry Pi and HAT.

   Caution

   Calibrate only after this. Calibrating on the wrong supply means calibrating twice.

Parts

• 2×12 V peristaltic pumpspart
• 2×250 ml GL45 borosilicate bottlepart
• 2×GL45 capspart
• 1×Silicone tubing, 50 cmpart
• 2×1/16" barb to male luer lockpart
• 2×1/16" barb to female luer lockpart
• 2×0.2 µm hydrophobic vent filterspart
• 1×12 V power supplyearlier step

Check your work

1. Under [PWM] on the Configuration page, what do channels 2 to 4 say?

   • 2=media, 3=waste, 4=relay
   • 2=waste, 3=media, 4=relay
   • 2=media, 3=waste, 4=waste
   Show the answer

   Answer: 2=media, 3=waste, 4=relay

   • If you see 2=waste, 3=media, 4=relay: That is the MEP's mapping. On the AEP, set 2 to media and 3 to waste, and click Save.
   • If you see 2=media, 3=waste, 4=waste: Set 4 back to relay, and click Save: the CO₂ solenoidAn electric valve on PWM channel 4 that opens to sparge. It must be 3-way venting (3/2), so the line vents when it closes. is driven there.

2. Which PWM channelOne of the HAT's five switched power outputs. In this build: 1 stirring, 2 media pump, 3 waste (product) pump, 4 CO₂ solenoid (relay), 5 heating. is the product pump's lead plugged into?

   • PWM 2
   • PWM 3
   • PWM 4
   Show the answer

   Answer: PWM 3

   • If you see PWM 2: Swap the leads: media pump on PWM 2, product pump on PWM 3.
   • If you see PWM 4: Move it to PWM 3: PWM 4 drives the CO₂ solenoidAn electric valve on PWM channel 4 that opens to sparge. It must be 3-way venting (3/2), so the line vents when it closes. relay.

3. What is plugged into the HATThe Pioreactor circuit board that plugs onto the Raspberry Pi's pin header. It carries the PWM and LED outputs and the 12V barrel jack.'s barrel jack now?

   • The 12V supply
   • Nothing: it came out
   Show the answer

   Answer: The 12V supply

   • If you see Nothing: it came out: Plug the 12V supply back in before you calibrate. Calibrating on the Pi's own supply means calibrating twice.

≈ 0.02 g CO₂e per view