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MAX31856
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

MAX31856

by Teus6789 on Tue Jul 05, 2022 10:16 am

L.S, In my case I like to program the ADAFRUIT-MAX31856 in PICbasic. I have uploaded the code in total and for insiders there is enough information to see exactly how the circuit needs to be made. My Max31856 works very well. I an amazed about the quality. Especially for a typr S couple. (after making thermocouple amplifiers and the translation software myself.) But during development of the code I saw that I always had to read twice to get one temperature reading. I do not want to put the MAX in the automatic mode. In the program TEMP3 contains the temperature information.
It may have to do with the remark that information is coming available AFTER cs has become back to 3.3 V ? It also may have to do with the 12 MHz as used by the PIC18F ? Or it is because I do not fully understand what the SHin and SHout statements do. Please help me if there is a better way to get the information from the MAX. No, I am not going to Arduino !!
Attachments
Reread03.txt
(11.19 KiB) Downloaded 9 times

Teus6789
 
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Re: MAX31856

by adafruit_support_bill on Tue Jul 05, 2022 10:36 am

As stated in the datasheet, in "One Shot" modem the conversion does not begin until /CS goes HIGH. And the conversion takes on the order of 150mS depending on your filter mode settings. If you try to read the result registers without waiting for the conversion to compete, the results are not defined.

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Re: MAX31856

by Teus6789 on Wed Jul 06, 2022 2:23 am

Thanks a lot for the quick answer. I suppose that you mean that I have to insert a 200 msec delay between the SHin and SHout statement ?

Teus6789
 
Posts: 3
Joined: Tue Jul 05, 2022 9:43 am

Re: MAX31856

by adafruit_support_bill on Wed Jul 06, 2022 5:53 am

That would be one way to do it.

If you configure the device for automatic conversion mode, the result registers will be updated every 100ms and you can read valid data at any time with no delay.

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Re: MAX31856

by Teus6789 on Thu Jul 07, 2022 6:00 am

Thanks for the help, it made me understand much better how the Max31856 has to be used. I see that more people are interested in the source and I wants to share the updated program for you.
Teus6789
Attachments
Reread03.txt
(10.87 KiB) Downloaded 2 times

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Posts: 3
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Please be positive and constructive with your questions and comments.