SD Card Read/Write with MAX 31856

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pdschroder
 
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SD Card Read/Write with MAX 31856

Post by pdschroder »

I'm working on a project that needs to read and write files from a SD Card reader (ID 254) and read thermocouples on four MAX 31856 (ID 3263). I can read and write files as long as I don't begin any of the MAX31856's. If I do that, I get an error when I try to open the SD card for writing, but it appears that I can read the SD card once before I attempt to write to it. The thermocouple readers will work while the SD card gives errors.

Are these two components compatible?

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pdschroder
 
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Re: SD Card Read/Write with MAX 31856

Post by pdschroder »

I just confirmed that I can read the SD card once, but cannot read it again if the thermocouples have been started. It doesn't matter if I attempt to write to the SD card between reads.

The controller is a Feather M4 Express.

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Re: SD Card Read/Write with MAX 31856

Post by adafruit_support_carter »

It sounds like the chip select (CS) for the SD card is not being managed correctly. What library are you using for SD card access?

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pdschroder
 
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Re: SD Card Read/Write with MAX 31856

Post by pdschroder »

The library is SD by Adafruit Industries. Should I be using SDfat--Adafruit fork? I tried SDfat-Adafruit Fork, but with it I can't get the SD reader to initialize. I've read something about SS needing to be an output, but I don't understand what SS is on a Feather M4 or M0.

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pdschroder
 
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Re: SD Card Read/Write with MAX 31856

Post by pdschroder »

Update: I compiled and downloaded code to try to see if the SdFat library would work better, but I couldn't get it to work at all. Then I recompiled the code that hadn't been working before, and it worked! As far as I know, I made no changes to either the wiring or to the code, but there's nothing to fix now.

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