Temperature reading negative

I am trying to get used to Cayenne by doing some of the tutorials.
I am trying the temperature one, but I did not have a TMP36 but I only had a LM3502.
it seems to be sensing, but is registering a negative value and if you warm it up the numerical value decreases.
Is there a way of calibrating the sensor to read correctly?

I found a LM35, but it still reads negative.

are you using arduino, raspberry with agent or python?

Just following the tutorial.


Tony Hudson

i mean you have connected LM3502 to arduino or raspberry???

Yes! I went through the tutorial and connected it as shown in the diagram. I checked the data sheet to check that the pin out. Would the output be different for this device?
Went through the normal connection routine and uploaded the sketch.


Tony Hudson

do you understand what i am saying? you have still not mentioned which device you are using.

I mentioned the devices I have I can connect either to test. I am using the TMP36 code and let’s say I’m using the LM3502 device.
Does that make it any clearer?

sorry, but i cannot help you.


Do you know for what an LM3502 used?

Sorry I did not have a magnifying glass and I thought it said TM3502, But I have found my Magnifying glass and it says TM 35 DZ.
This is a Temperature sensor.
I’m afraid you will have to compensate for me as I am 71.

okay, next which microcontroller or single-board computer are using to connect the TM36DZ sensor? You need a device which connect to the internet so that you can send the TM35DZ sensor data to cayenne. Here is the list of all supported devices https://developers.mydevices.com/cayenne/docs/supported-hardware/#supported-hardware

Arduino Uno

with ethernet or wifi shield or? to connect to internet.

Yes! W5100
I have post before on another post. Thought you may have remembered.

Do you have data sheet of TM35DZ? can you share it here. there is limited resource on this device. Are you able to read the TM35DZ sensor data on your arduino? or do you have any link on it?

I did try to attach, but you don’t support PDF’s.
Here is a link:

i came across this, i guess it is the same sensor https://create.arduino.cc/projecthub/infoelectorials/project-003-arduino-lm35-temperature-sensor-project-0a43ba
can you try and see if it works.

I have looked at this and I am sure that it is the correct one.
The sketch has not been Cayenne’ised.
I have made an attempt to write the Cayenne stuff in, but I have not got it right as I get an error.
‘unterminated argument list invoking macro “CAYENNE_LOG”’[LM35

LM35 error.txt (28.7 KB)
LM35 Sketch.txt (1.2 KB)
Is there any tutorials on how to write code for Cayenne?
For now can you point out my errors in my attempt?