Hello,
I have upgraded my Pioreactors with an external power source of 12V but only the leader seems to be getting the extra voltage.
When i look in the SYSTEM tab of each reactor the leader is at 12.15V, worker1 is at 5.1V and worker2 doesn’t say anything,
I am rebooting them but nothing changes. And i have moved the shunt connector to the right position.
What am i missing?
Hi @Eleni_M,
Hm, that’s a new one I’ve never seen before. Can you turn on stirring - you should audibly notice a different pitch / noise level with 12V supplied. Few other things:
I’ll think more about this, but start with ^
I checked that everything is pushed all the way in and in the right place. I am using the same PSU for all three of them which is supposed to output 12V, but i also tried with the raspeberry HAT PSU which outputs 8V, but what i get is still only 5.1V. A few days ago when i was testing the external power supply i was doing that with worker1. And it was getting 12.15V. I am also measuring the output with a multitester to make sure that what i see in the software is really what i am getting.
I will try reinstalling the workers.
It is odd that for worker2 there is no info at all for the voltage.
Is it normal that the in the SYSTEM tab the leader doesn’t have anything written next to the software version, while the workers have the most resent update?
Probably you updated the software without restarting the leader - that’s fine. A restart is needed for version information to show up in the UI.
Yes, especially after a restart. But I would ignore that for now to focus on the voltage issue.
I am also measuring the output with a multitester to make sure that what i see in the software is really what i am getting.
How are you measuring the output of the Pioreactor’s PWM? Did you connect the multimeter to the PWM outputs (1,2,3 or 4), and set the DC % to 100%?
It’s all a bit odd, since we test exactly this in our internal QA: we put in a 12V PSU, and move the shunt back and forth and confirm the signal changes.
Here’s a little Python script you can run to constantly be reading the PWM output voltage:
from pioreactor.hardware import voltage_in_aux
import time
while True:
print(voltage_in_aux())
time.sleep(0.1)
Save this to your worker that’s experiencing a problem, and run it with python my_script.py
The voltage_in_aux is reading the ADC on our HAT, that is measuring the voltage supply to the PWM rail (and hence the PWM output). It should say 12V when a 12V barrel connector is in and the shunt is in the right position. The voltage_in_aux is also what populates the UI field.
Yes i am measuring the output in port 4 where i have the air_bubbler at 100%, 50% etc…
That sounds reasonable. And when you vary DC%, you should see the output voltage vary. Hmhmhm.
A few days ago when i was testing the external power supply i was doing that with worker1. And it was getting 12.15V.
So it sounds like at one point, it was working? Was any very high load attached to the PWM outputs that could have fried something? Something that consumes a lot of current?
To help debug, you can plug / unplug the barrel connector and move the shunt while the Pioreactor is on - it’s generally fine. Maybe just don’t have a load (i.e bubbler or pump) attached.
ok i did that for worker1; it prints 5.1000000000000005 when the shunt connector is in the aux_on position (closer to the led ports) and 5.2 when it is in the aux_off position (the default). the output doesnt change by me bluggin in and out the PSU barrel 
Does using the (working) 12V PSU from the leader do anything different?
We’re discussing internally other ideas, stay tuned!
Still 5.1000000000000005 with the leader’s PSU and shunt connector.
Ok i think i may have messed up the HATs somehow, because when i put the SD card of worker1 in the pi of the leader then i get 12.100000000000001V with the PSU and 5.1000000000000005 without.
Which mostly confirms it’s not a software issue (which we didn’t think it was).
yes, i don’t understand what i did that fried the HAT… but i guess buying new HATs is my only way out of this mess…
thank you for looking into it 
guess buying new HATs is my only way out of this mess…
we’re still investigating, no need for that yet.
If you can tell us what loads you were using the 12V connector for (product + supplier), that can help us understand.
do you mean what i was trying to power with the 12V? i was using the air_bubbler plugin to power a a heating pad
Yea, that’s what I meant (load == power). Okay we’ll get back to you!