Due to high demand expect some shipping delays at this time, orders may not ship for 1-2 business days.
0

Max 31865
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

Max 31865

by Itay21 on Thu Mar 11, 2021 10:53 am

Hey,

I'm trying to run a program to check temperature by PT1000 and PT100 sensors and to present it on touch LCD screen:
-PT1000: cannot read the temp at all. every sec the temp is -246.000(guess a default value)
-PT100: if i unplug the screen it does work. but when i plug back the screen it doesnt.
i was thinking that the issue caused by SPI0. i'm using the adafruit_max31865 code for reading the temperature sensor.
attached link:
https://learn.adafruit.com/adafruit-max ... cuitpython

moreover, I gues that the screen "controls" the SPI0, because when i'm trying to run the program, I've received an /dev/spidev0.0 is not shown error.
what should i do??
how can i open the SPI1 for the sensor running and the SP0 for the screen?
my wish is to present the current temperature on the screen.

Thanks :)

Itay21
 
Posts: 7
Joined: Thu Mar 11, 2021 10:44 am

Re: Max 31865

by adafruit_support_carter on Thu Mar 11, 2021 11:36 am

Have you first verified that each items works as expected stand alone?

Just the PT1000 by itself - work as expected?
Just the PT100 by itself - work as expected?
Just the LCD screen by itself - work as expected?

For each, can just use an example from the respective device library.

adafruit_support_carter
 
Posts: 20078
Joined: Tue Nov 29, 2016 2:45 pm

Re: Max 31865

by Itay21 on Thu Mar 11, 2021 12:26 pm

Hey,

The LCD screen works as expected.
The PT100 works as expected.
Just the PT1000 doesn't.

Itay21
 
Posts: 7
Joined: Thu Mar 11, 2021 10:44 am

Re: Max 31865

by adafruit_support_carter on Thu Mar 11, 2021 12:34 pm

Just the PT1000 doesn't.

OK, let's figure that out. Post a photo of your PT1000 test setup showing how everything is connected.

adafruit_support_carter
 
Posts: 20078
Joined: Tue Nov 29, 2016 2:45 pm

Re: Max 31865

by Itay21 on Thu Mar 11, 2021 12:53 pm

I'm pretty new to this stuff.
To take a picture of the PT1000 with the max31865 connection?

Itay21
 
Posts: 7
Joined: Thu Mar 11, 2021 10:44 am

Re: Max 31865

by adafruit_support_carter on Thu Mar 11, 2021 12:56 pm

Yep. Basically, set things up with just the PT1000 breakout per the guide:
https://learn.adafruit.com/adafruit-max ... duino-code
and post a photo of your setup similar to the one in the guides. So we can see all the wires and how they go from the main board to the breakout, etc.

adafruit_support_carter
 
Posts: 20078
Joined: Tue Nov 29, 2016 2:45 pm

Re: Max 31865

by Itay21 on Thu Mar 11, 2021 1:22 pm

I follow the instructions there, and I'm using raspberryPi board.
IMG_8039.jpg
connection to raspberry, to use SPI1. GPIO16-CS, GPIO21-SCLK, GPIO20-MOSI, GPIO19-MISO
IMG_8039.jpg (106 KiB) Viewed 78 times


IMG_8038.jpg
IMG_8038.jpg (145.23 KiB) Viewed 78 times

Itay21
 
Posts: 7
Joined: Thu Mar 11, 2021 10:44 am

Re: Max 31865

by adafruit_support_carter on Thu Mar 11, 2021 1:30 pm

How are you currently accessing the Pi? Remotely via SSH? Or more directly with an attached keyboard and display?

adafruit_support_carter
 
Posts: 20078
Joined: Tue Nov 29, 2016 2:45 pm

Re: Max 31865

by Itay21 on Sat Mar 13, 2021 3:05 pm

By ssh..

Itay21
 
Posts: 7
Joined: Thu Mar 11, 2021 10:44 am

Re: Max 31865

by adafruit_support_carter on Mon Mar 15, 2021 2:23 pm

Since you accessing via SSH, can you try without the LCD screen attached. So the only thing attached is the PT1000.

The only difference between the PT100 and PT1000 is the reference resistor. Are you generally wiring and connecting these in the same way?

adafruit_support_carter
 
Posts: 20078
Joined: Tue Nov 29, 2016 2:45 pm

Re: Max 31865

by Itay21 on Thu Mar 18, 2021 3:09 am

When I've tried it without the screen, the PT1000 still didn't work well.
It has just gave me -242.000 C.
Yes, I plugged it in the same way

Itay21
 
Posts: 7
Joined: Thu Mar 11, 2021 10:44 am

Re: Max 31865

by adafruit_support_carter on Thu Mar 18, 2021 10:32 am

Are you setting up your sensor with something like this:
Code: Select all | TOGGLE FULL SIZE
sensor = adafruit_max31865.MAX31865(spi, cs,  wires=3, rtd_nominal=1000.0, ref_resistor=4300.0)

to specify that you are using 3 wire mode with the PT1000 resistor values?

Does the value at least change if you warm up the sensor? Pinch it in your finger, or breathe on it, etc.

adafruit_support_carter
 
Posts: 20078
Joined: Tue Nov 29, 2016 2:45 pm

Re: Max 31865

by Itay21 on Fri Mar 19, 2021 4:18 am

Yes, i'm using exactly this code. I receive just -242.000 as a temp, and 0 resistor.
I think it just doesn't read the temperature.

Itay21
 
Posts: 7
Joined: Thu Mar 11, 2021 10:44 am

Re: Max 31865

by adafruit_support_carter on Fri Mar 19, 2021 10:40 am

Weird. Let's double check wiring again. Can you post a new photo showing how you are connecting everything without the display on.

adafruit_support_carter
 
Posts: 20078
Joined: Tue Nov 29, 2016 2:45 pm

Please be positive and constructive with your questions and comments.