Contact-less Infrared Temperature Sensor - MLX90614

adhanabal

hello all
Im building a SLS 3d printer with duet3 6HC v1.1,
I want to have surface temperature regulation of powder using IR heaters, which will have temperature reading from MLX90614 - IR sensor,
the problem is i wont able to directly connect that with mainboard,
I tested the sensor with arduino uno and it works fine,
Is there anyway i can get the temperature reading on duet from the mentioned sensor?
so that i can use layer change script to regulate my temperature.
regards

zapta

Datasheet in the link below if anybody is interested. It seems to support SMbus and PWM output.

https://www.melexis.com/en/documents/documentation/datasheets/datasheet-mlx90614

dc42

@adhanabal assuming that you don't want to change the firmware, I can see two ways to interface it with the Duet:

Use the PWM output mode. Feed it through a R-C smoothing network to an analog input of the Duet and configure a Linear Analog Sensor to use that input. Preferably, use the 3V variant of the sensor and feed it from the 3.3V supply on the temperature daughter board connector (not 3.3V on the IO ports, which is a different 3.3V supply) to avoid errors caused by the Vcc supply to the sensor and the Duet analog reference drifting by different amounts.
Use a Arduino Nano or Pro Micro to read the sensor data in SMbus mode, and generate a smoothed PWM signal to feed to the Duet.

It wold also be possible to add a driver to the firmware to read it in SMBus mode directly.

Caution: in SMBus mode the SDA signal will be sensitive to noise, so it will almost certainly need to be shielded unless you have an Arduino or other interface device very close to the sensor.

adhanabal

@dc42 thank you , im major in Mechanical, i have to go through lot of this from your solution, i ll check and try, any one else have successfully done this before?
Im using arduino UNO, is it okay or should i change to arduino nano?

dc42

@adhanabal Arduino Uno is OK, the Nano is just a smaller version.

zapta

@dc42, will this improve the accuracy of the output voltage generated by the Arduino?

https://www.adafruit.com/product/935

dc42

@zapta said in Contact-less Infrared Temperature Sensor - MLX90614:

@dc42, will this improve the accuracy of the output voltage generated by the Arduino?

https://www.adafruit.com/product/935

I assume you would use an Arduino to drive that board. It has the advantage that you would not need to produce the output by filtering a PWM signal. The accuracy of the reading from the Duet would depend on how well the internal 3.3V rail on the Arduino and the Vcc supply to that board track each other.

Is this a one-off project, or something that you hope to manufacture? How accurate do you need the temperature reading to be?