Go Down

Topic: Heat detection with thermopile sensors/non-contact / NEWBIE (Read 2408 times) previous topic - next topic

a spy

I have to detect heat in the range of approx. 50° C and a distance between 10 - 30 cm. I have already read the options TPA81 and Melexis MLX90614-boards with their price between 40 - 80 €. 

Is there a possibility to connect only a TPS334 (thermopile sensor) or MLX90614ESF-AAA components ? They should give a return value (voltage!) for my analog-input (or with i2c?), in the program I will convert this value into a approx. temperature. Has anybody experience with such a (cheaper) approach ?

Thanks in regard
arduino newbie...


you've picked a bit of a tough one.  Do you need to detect temperature in absolute value or only a change in heat?  I think the TPA81 will only detect a moving/changing  heat signature.

I have some experience with this device:
"Parallax MLX90614 Infrared Thermometer Module (10° FOV)"

I have it working; it talks over serial RS232 to Arduino.  The only problem I have is that the Emissivity value cannot be changed.  I guess one other issue is that this solution is a bit expensive.

A nice solution (if you can figure it out) would be to use this device: MLX90614ESF-AAA and communicate through I2C.  However, the device technically is SMBUS (not I2C) and some references say it will work while others say it will not.  The best answer I found is that it is more compatible at 3.3V than 5V due to logic level differences.  For an example of this check out Sparkfun.  They have made a board that includes the Melexis sensor and some type of AVR chip to help us it.  I find the communication protocol with the MLX90614 very confusing but if Sparkfun has included the code with their board you will have a head start.

There is also some information on diydrones.com

a spy

thanks a lot. I have to detect this hotter space, the temperature is not relevant. Therefore I thought there works simply components like fotoresistors...
arduino newbie...


Since you have some experience with the 10 deg FOV sensor, do u know which material is the extra housing.

The 35/10 deg FOV sensors have an extra housing on top of the 90 deg FOV, but i simply cannot find what it is made of.



sorry, I cannot be certain about the plastic.   It might be Nylon or Delrin.  The datasheet doesn't say and I don't want to set mine on fire to find out what it is :smiley-eek-blue:


Ok, so you are sure it is some plastic like nylon.
I was thinking that the housing should be done in a highly conductive metal, like copper, so that it would be easier to avoid temperature gradients, and to achieve a faster equilibrium temperature with the underneath sensor.

Also, won´t nylon be a problem if it warms up, due to its high emissivity?


Go Up

Please enter a valid email to subscribe

Confirm your email address

We need to confirm your email address.
To complete the subscription, please click the link in the email we just sent you.

Thank you for subscribing!

via Egeo 16
Torino, 10131