Getting wrong value from sensor

Hey guys,

I’m having a strange issue with my Temp7410 module and don’t know where to start debugging.

Following situation:

I request the temperature from the sensor every second.

Everything works fine, but
-) when I touch the sensor IC or
-) bend a cable or
-) blow the sensor (smoothly with my mouth)

I sometimes get ‘0’ as return value.

I checked the solder joints, desoldered everything and soldered it again,
changed the cables, and decreased I2C clock frequency from 400kHz to 100kHz.

Last night I left it alone in the living room, capturing the temperature, and there was not a single ‘0’ reading.

I built a second circle on a breadboard, to see if it’s a layout issue. But same behavior.

So I expect it to be a problem with my driver, but I’m not doing anything else than reading a register from the sensor every second. I don’t know what could be wrong there.

You can find the driver here:

Additionally I have attached an image of the circuit.

Does anyone had a similar issue? Or could give me a hint where to start?


What’s your conversion time? Length of the cable?

According to the datasheet, the conversiontime is 240ms.

Have tried different cable lengths, from 10cm to 20cm. But shorter cable has no positive effect.

No ideas? :frowning:

Remove the pullups from SDA and SCL?

I try that! thx