bhills

That is a good idea. Thanks zeke, I will give that a try. I figured out the initial issue. It was mostly a hardware problem. The SD card reader was not getting the voltage that it needed to write. I rewired it, gave it ~0.1 sec startup time between when power is turned on and when I start the initialization. It seems to be working well now. Thanks for your help

Is this somehow different from your initialization procedure? This is written into the loop so it should initialize the card every loop. FatFs.begin(CS_PIN); // initialize FatFS library calls rc = FatFs.open("LOG.TXT"); // Specify file FatFs.lseek(file_byte); // Move forward to current location in file. Commands are the same as that in the PFatFsFileTest.ino example file. The SD card reader is supplied with power before the above commands, then instructed to write, then power is removed. Thanks

Thank you, I will give this a try

Hello, I am working on a project in which we are using the MSP4305969 to measure temperatures and write data to an SD card. The datalogger is in a remote location, so the system needs to conserve enough power to log for a full year. In order to do this we are logging only every 15 minutes and powering everything down to a sleep mode between measurements. We use a transistor as a switch to take power away from the line of temperature sensors while the board is sleeping. That all works fine, my issue is with the SD card reader. We are using the "slot socket" for arduino https://www.amazo