T
Bewertet in den USA am19. Januar 2025
It's really, really hard for me to recommend this module. There are critical problems out of the box.The documentation is terrible which does not help. Thanks to the info from another review, I was able to get this working and it is excellent and reliable with modification. I'm an electrical engineering student, it shouldn't be this much of a pain to get a temperature sensor setup.
nat
Bewertet in Kanada am 30. September 2024
As the title states the module doesnt work, but the rtd works fine.
Dr G.
Bewertet in Großbritannien am 23. Juli 2024
I bought this product to use with an Arduino Nano for temperature measurement in the range -10/+10C.The PT100 sensor appears good, showing a resistance of 100.0 ohms when immersed in a properly prepared distilled water/ice slurry measured with an 'old school' analogue bridge, making appropriate allowance for lead resistances.The same cannot be said for the module which is intended to measure the PT100 resistance, digitise the measurement and make the result available for reading over the SPI bus. I tested the module/sensor combination using Arduino libraries written specifically for these modules using both hardware and software controlled communication over the SPI bus. In all cases the module reported nonsensical results most of the time. Occasionally, with the water/ice slurry I would get a reading in the region of 100.5-101 ohms corresponding to a temperature in the region of 1-2 degrees C.Eventually I gave up trying to diagnose the problems and bought the Adafruit version of the module which just worked, giving a consistent temperature of 0.2C in the ice bath. As I used exactly the same physical/software setup with both modules I am very confident that my procedure/programming was not at fault.I realise that this review is based on a single board, but given my experience I can't recommend this product. The two star rating reflects my positive experience with the sensor which appears fine.
Doc D
Bewertet in den USA am13. Dezember 2024
It took me quite a bit of time to finally get this kit working. This isn't a plug-and-play module. The manufacturer of the board didn't make it easy for us. It comes with jumpers set for a 4 wire RTD sensor and the sensor provided is a 3 wire. Go figure. While a 3 wire RTD can theoretically be connected as a 4 wire sensor, it's tricky. So after reading several guides and schematics, you will need to solder a couple of tiny surface-mount pads together in 2 spots. In another area you have to cut a very thin jumper between pads (get your magnifying glass to find it). Once you fixup the hardware, then you need to get the firmware properly configured. One issue is that the kit comes with a PT100 RTD sensor which is 100 Ohms at 0 degrees C. The data sheet for the MAX31865 specifies that for a compatible range, the Reference Resistor should be about 4 times the nominal resistance of the RTD (100 Ohms x 4 = 400 Ohms. However the resistor soldered onto my board is a 4300 Ohm resistor. This plays a significant factor in the firmware calculations when trying to measure the RTD resistance. If you find example firmware, you will need to go through it carefully and reset various configurations such as the ADC range (12 to 15 bits), the Reference Resistance, the conversion formulas for temperature in C and F, the SPI settings (Mode, HW or SW version (I suggest using the hardware SPI), calibration, etc). My Masters Degree in Electrical Engineering (Cum Laude) from a Big Ten University came in handy for this project. Once I got it configured, the temperature readings were accurate and stable so the chip itself performs well.