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By trackerj
#71721 I have used a ESP8266 nEXTEvo board:

nEXT_EVO_kit_s.jpg


The provided piece of code is still happily running since 2016

Pin allocation:
MISO = 5 --> GPIO14
CLK = 7 --> GPIO13
CS = 6 --> GPIO12

What version of Nodemcu LUA do you have there?

TJ.
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By rpav
#71724 Thank you for your reply.

I've latest stable version of Nodemcu LUA firmware: 2.1.0-master_20170824
I don't think that this is the software issue.

First of all I have to confirm, that you used the right pins, all of them are for HSPI. I believe that using any others can lead to hangs and reboot. This was exactly what I observed and later I remember, that I've already reported this problem: https://github.com/nodemcu/nodemcu-firmware/issues/1602

So I've changed to:
local MISO = 6 --> GPIO12
local CLK = 5 --> GPIO14
local CS = 8 --> GPIO15

But there is one more (or even more :| ) issue. I'm afraid it is not ESP even software issue, but the modules one. I found description of very similar problem here:
http://forum.arduino.cc/index.php?topic=155641.0

Now it seems to me that something wrong is with MAX module. Can you pls specify which kind of MAX31855 module is used in your project?

I'm using MAX31855K chip (probably version 1.0):
Image
Also, I'm not sure if the Thermocouple Probe is connected right, is red for minus and blue for plus? Anyway I've try both variants without the reasonable result.
Which MAX module is in your project?
Thank you for answer.
Roman
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By trackerj
#71727 I have not used a ready-made MAX31855 module i've just designed a custom one for that specific project.
Ordered MAX31855 from Farnell, MAX31855KASA+ to be more specific.
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By rpav
#71762 Just to be sure I'm not kidding, I tried to connect MAX31855 module do R-Pi and use Adafruit library. The module measurement was totally incorrect:
PiMAX31855.png


I've ordered new module form Aliexpress and will report to this thread if it helps. I hope it will.

Thank you trackerj for help and your code.
Regards,
Roman