Power supply and RTD connection basic setup, RTD data acquisition hat


New member
Hi folks,

I purchased the RTD data acquisition raspberry pi hat back in 2019, got sidetracked, and am now finally back at it. The board is labelled 5.1.

I've never used a Pi hat before, so I'll apologize in advance if my questions are pedestrian.

1. I plugged the hat directly onto the gpio pins of a raspberry pi I have lying around, which is being powered by a POE-splitter from a POE switch. Does the hat need a separate power supply too, or does it somehow draw power from the gpio bus? If the hat needs a separate power supply, I see a pair of connection points at the upper right of the board labelled 5V and GND, does that imply I need to somehow splice a pair of raw wires from a 5vdc power supply to connect to those connection points on the board?

2. I have some PT100 RTD's I intend to use for testing, with 2x red wires and 1x blue wire. I strongly suspect the RTD is between the blue and either of the red wires, and I should connect it to the hat connection points in that manner. Correct?



New member
Update: I simply tried it, and lo and behold, it seems to be working.

Power question - it appears simply plugging it into the gpio header is sufficient, at least for 1x board with 3x RTDs. At what point would a separate power source become needed, how many boards and/or RTD's?

RTD connection: I seem to have guessed correctly.


Staff member

Sorry I did not manage to answer earlier but I am glad you figure out.
The card consume about 50mA with all the sensors connected so you can power all the cards (you can stack up to 8 on a single Raspberry pi) from the gpio connector.