We have been working with a new external temperature sensor, and it’s really great:
This is great! also functional for the XR?
Yes, works with the 40ml XR too!
Sounds exciting! What was the culture volume in this instance? @CamDavidsonPilon
I believe it was 25ml. Let me know if theres a volume you want to try.
What is the reason behind using Spec A instead of Spec B? I assume to reduce deviation from the actual temperature at the bottom? @CamDavidsonPilon
SPEC A was chosen since it’s more likely to be viewing glass → liquid, vs glass → air (the former being our actual target). You could try SPEC B, and perform a temperature offset calibration (new protocol available with the plugin) to get more accurate too.
I’m excited for the spectrometers!!
Coming soon?
@Pedre91 that’s available now! The spec board and our plugin can do spectroscopy.
FYI there’s a new spec board with more channels: Adafruit AS7343 14-Channel Light / Color Sensor Breakout [STEMMA QT / Qwiic] : Adafruit Industries, Unique & fun DIY electronics and kits
Comparing the two boards wavelengths:
AS7341
415 445 480 515 555 590 630 680 ---- 910
AS7343
405 425 450 475 515 550 555 600 640 690 745 --- 855
Plugin coming soon!
Hey,
I am trying to run cultures at 52 °C based on your internal tests. But for me it seems like not all pio’s manage this (See picture). I suppose they are max heating but not managing to heat the whole liquid column to 52.
I am using 30 mL in the 40mL v1.5’s. Maybe the fact that its 30 mL is an issue? But you used 25 in your tests, so not that big of a difference? Or maybe room temperature here is a lot colder than it is in Canada 
? Jokes aside, I think RT here it is also 20 °C.
Anybody got some suggestions? Maybe something in the hardware installation that gives this difference in heating capacity between units. Contact between PCB, rubber, and vial?
For now I keep using an incubator at around 35 °C and that solves the problem. But it’s obviously more of a hassle with cables, pumps, media, etc…
Thanks!
Sure 30ml is bigger, sure. Can you check that your PWM is at nearly 100%? SSH into any worker that is lagging and run:
pio cache view pwm_dc
and you should see pin 18 near 100%?
A few other checks:
Sorry, I meant a new sensor that enables GFP and RFP measurements. That would be amazing! 
Actually its only at between 80 and 90 % in the two where I checked a couple of times. Temperature maxing out at 48 and 49 °C.
Output I get
pioreactor@Pio08:~ $ pio cache view pwm_dc
17 = 20.109
18 = 82.16
On the other things:
So I tried 30ml in one of our machines. See below:
Starting at 19C, it’ll probably stabilize around 51.5C.
The heater does start the throttle when the PCB gets to >= 78C, which is why you see DC% around 80%-100% at the asymptote. There is a small bug here that causes the DC% to throttle too aggressively, that’s fixed in plugin v0.2.9, but I don’t think that’ll significantly increase the top-end.
- what is a top O-ring? the rubber ring inside the pio? We have those installed
Yes, that’s good.
I’m going to run a few more tests here to see if there are any insulation quick wins. I’m also going to drop the volume from 30ml to 25ml to see what changes, too
Also, perhaps not insignificant (but maybe so), I’m using RPi4s, which do output more heat passively vs RPi Zero 2w
one addition/thought.
I am using these white lids with a rubber stopper for anaerobic growth. There’s a tiny bit of space between the pio sleeve and the lid. Might that have an effect?
ha! Coincidentally, I’m using the same lids
I just tried two things:
I suspect it will stabilize around 55C.
How do I do that?
Also, this is not 100% obvious, but the plugin uses the computed volume to assist in inference. So make sure your volumes are correct. Either do this in:
[bioreactor] parameter initial_volume_ml,(I’m working on a better way to make this easier to control)