Andy's Workshop Forums

General Category => General discussion => Topic started by: Andy Brown on September 16, 2017, 09:11:03 am

Title: Process automation: accurate temperature sensing
Post by: Andy Brown on September 16, 2017, 09:11:03 am
I've just published a new article (http://andybrown.me.uk/2017/09/02/temperature/) describing how I built a temperature sensing board to compliment the earlier relays and triacs board.

(http://andybrown.me.uk/wp-content/images//brewery/system/temperature/ebay-stainless-reading.jpg)

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.

(http://andybrown.me.uk/wp-content/images//brewery/system/temperature/both.jpg)
Title: Re: Process automation: accurate temperature sensing
Post by: VirgilBo on October 08, 2017, 05:35:23 am
Awesome article as per usual, Andy! Thanks for sharing.
Title: Re: Process automation: accurate temperature sensing
Post by: Bwanna on August 06, 2019, 08:58:43 am
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,
Title: Re: Process automation: accurate temperature sensing
Post by: 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.
Title: Re: Process automation: accurate temperature sensing
Post by: Bwanna on August 06, 2019, 10:02:00 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.