I am having an issue regarding getting sensor data in node red i am using an MPRLS sensor. arduino nano and pi pi is getting 5V from a strong power supply (not the normal netconnector) i can get the MPRLS to work if i use: Nano 5V Nano GND Nano A4 SDA Nano A5 SCL But things get odd when i sw…

To me, at least, your explanation is not clear. It might be a good idea to draw a circuit diagram (even a photo of a Diagram). This might help us understand better what you are trying to do.

Ok. i'll draw. 3 drawings so might take a few min This works 100% as it should. Nano is powered through USB [image] This seem to work (i2c adress is visible, not sure about the code) [image] This does not work: Nano is powered through USB [image] This does not work: Nano is powered throu…

I suspect you have not joined GND on all components.

That is correct. should I connect all the GND? or only the 5V hardware (I have a DRV8255 powered with 12V)

[image] TotallyInformation: But why not power the microprocessor what do you mean?

[image] TotallyInformation: Ground must be common Also from 12V? I thought this could damage things (5V gnd and 12V gnd combined)

Unless I've misunderstood, in your 2nd image, you powered the sensor from a power supply but the MPS from USB. Power the MPS from the power supply and let the sensor take its power from the MPS. Then you, by definition, have a common ground and no issues and you've saved yourself an extra (USB) powe…

Ah, the nano, Yes there is 12V applied to it in the testing. didn't change the problem. I used the usb to also check serial monitor on arduino IDE.

[image] WBr: Also from 12V? I thought this could damage things (5V gnd and 12V gnd combined) Are you telling me that you are powering the sensor from 12v? If so my suggestion won't work of course. But I assumed that the sensor was low voltage since you said you could power it from the MPS. In…

SDA SCL 5V GND different power supply; errors

Hardware

TotallyInformation 19 May 2023 20:29 6

Ground must be common. But why not power the microprocessor from your power supply and the sensor from the microprocessor - then you would avoid all of the issues.

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SDA SCL 5V GND different power supply; errors

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