How to solve the problem that the ADC reading of MSP432 is affected by external electrical appliances?

davidchee

How to solve the problem that the ADC reading of MSP432 is affected by external electrical appliances? [Copy link]

I need help from the experts in the forum. I use MSP432P401R to read the temperature of the thermocouple, and then use a heater to perform point heating to control the temperature. The thermocouple voltage signal is transmitted to the ADC interface of the microcontroller through the AD8495 amplifier. The ADC is set to use the internal 2.5V reference voltage. Now I find that when the heating is turned on, the temperature read by the microcontroller will instantly rise by several degrees. When the heating is turned off, the temperature will suddenly drop by several degrees. It feels like there is interference from the heater. I am not sure whether it is common mode or differential mode interference. How can I solve this problem? Thank you

月下良缘

No way!

alan000345

This has errors, so pid-type corrections are needed.

zhangleiat185

Is it because your thermocouple and heating rod are too close?

xsn5

Excuse me, can you tell me about the internal temperature sensor module?

davidchee

xsn5 posted on 2019-6-4 16:11 Can I ask about the internal temperature sensor module?

The AD8495 used, the specific reference manual can be searched on the AD official website

davidchee

zhangleiat185 posted on 2019-5-28 22:13 It's not that your thermocouple and heating rod are too close

It's quite close, so it's a bit troublesome.

zhangleiat185

davidchee posted on 2019-6-28 12:43 It is quite close, so it is a bit troublesome

That is probably caused by being too close. If the distance is too close, you can consider controlling the power of the heater and not letting it work at a constant power.

davidchee

zhangleiat185 posted on 2019-6-28 21:09 That is probably caused by being too close. If the distance is too close, you can consider controlling the power of the heater and not letting it work at constant power

Thanks for your reply