Order #2733556-3471611041
I have purchased several MAX31865 and several different RTD PT100 sensors. All the sensors are three wire. I have checked the resistance of the wires, the matching pair is ~2 while the other single to the pair is ~109 ohms.
I am using the default MAX31865 sketch. The only time I made a change was when I tried using only two of the three wires on a probe. I still had the same result.
Adafruit MAX31865 PT100 Sensor Test!
RTD value: 0
Ratio = 0.00000000
Resistance = 0.00000000
Temperature = -242.02
Fault 0x40
RTD Low Threshold
I have been following this howto: https://learn.adafruit.com/adafruit-max ... -amplifier
I also have read through: viewtopic.php?f=31&t=166096
Attached are photos of my setup. If/When there needs to be a different angle for a photo, please ask.
Thanks,
-AJ
MAX31865 RTD Low Threshold
Moderators: adafruit_support_bill, adafruit
Please be positive and constructive with your questions and comments.
- ajokela
- Posts: 2
- Joined: Mon Dec 13, 2021 8:55 pm
MAX31865 RTD Low Threshold
- Attachments
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- sparkfun-uno.jpeg (487.49 KiB) Viewed 610 times
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- Three wire
- threewire.jpeg (333.81 KiB) Viewed 610 times
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- Three wire
- threewire-1.jpeg (421.1 KiB) Viewed 610 times
- adafruit_support_bill
- Posts: 88092
- Joined: Sat Feb 07, 2009 10:11 am
Re: MAX31865 RTD Low Threshold
The connections look good. Make sure that you have cut fully through the bridge on the "24" side of the ""24 - 3" jumper. It is hard to see in the photo.
- ajokela
- Posts: 2
- Joined: Mon Dec 13, 2021 8:55 pm
Re: MAX31865 RTD Low Threshold
Here are close up photos of the cut jumper.
I am not seeing any difference in the output. Still the RTD Low Threshold
I am not seeing any difference in the output. Still the RTD Low Threshold
- Attachments
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- signal-2021-12-14-200849.jpeg (173.85 KiB) Viewed 604 times
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- signal-2021-12-14-200907_001.jpeg (288.63 KiB) Viewed 604 times
- adafruit_support_bill
- Posts: 88092
- Joined: Sat Feb 07, 2009 10:11 am
Re: MAX31865 RTD Low Threshold
We can try replacing the board. Please contact [email protected] with a link to this thread.
Please be positive and constructive with your questions and comments.