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December 12, 2019, 09:49:19 pm

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SMF - Just Installed!


Process automation: accurate temperature sensing

Started by Andy Brown, September 16, 2017, 09:11:03 am

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Andy Brown

I've just published a new article describing how I built a temperature sensing board to compliment the earlier relays and triacs board.



Now that I've got sensing and switching I can mount these two boards inside a PC case and get working on the middleware software. Here's a picture of both the boards ready to mount in the case.


It's worse than that, it's physics Jim!

VirgilBo

Awesome article as per usual, Andy! Thanks for sharing.

Bwanna

Andy,

Don't mean to hijack this post, but I've starting planning a similar project and wanted to ask if you would have time to provide feedback?  More than happy to start a new post if you want.  Here's a quick summary of what I'm looking to do:

>Inputs: (6) K-type inputs and (2) 2-wire RTD
>SDI output goes to ESP32 running Ardunio IDE
>ESP32 outputs to TFT 320x240 display

Right now, I have a working version for just the 2 RTDs (and a few digital pressure sensors) with an Atmega328p and TFT display.  This project will add the k-types and a larger display. I've already successfully ported the code over for the display, etc. and am now working the inputs.

My first question is if you think the LTC2986 is an appropriate choice for obtaining input from the 8 (6+2) sensors and sending this to the ESP32 in via the SPI connections?

Thanks for your time in reading this.
Cheers,

Andy Brown

Hi, I think you may run out of inputs on a single LTC2986. I would recommend downloading the evaluation software from the analog.com site and running the configuration designer to see if what you're planning is feasible.
It's worse than that, it's physics Jim!

Bwanna

Quote from: Andy Brown on August 06, 2019, 09:47:20 am
Hi, I think you may run out of inputs on a single LTC2986. I would recommend downloading the evaluation software from the analog.com site and running the configuration designer to see if what you're planning is feasible.


I'll have to wait until later when I'm near my dev computer.  Maybe a simple question, but are both of the K-type wires needing to be connected to individual channels? ...or can one side of each of the 6 K sensors be tied to one channel?   With RTD's I've tied on side of those to 5v and then measured each separately on the 328p.